diskpar and Hitachi SAN for performance

We have a Hitachi Thunder SAN to host SharePoint databases. We are running
SQL server 2000 SP3 in a 2 node active/passive cluster. I have read articles
stating to run diskpar to align the offset correctly with the disks to
dramatically increase performance. I'm undecided on whether I should run
diskpar.
Does anybody have experience of seeing improvement using Hitachi SANs?
There seems to be more experience with Exchange than SQL out there.
--
Will RobinsonHi
Yes, run it. The alignment of OS blocks with the underlying SAN block does
eliminate the need for the SAN to do unnecessary IO.
Also, make sure that your formatting matches your SAN's block size. On or
Hitachi and EMC's, we format the drives with 64kb blocks, as this matches
SQL Server I/O sizes and our SAN's stripe size.
Regards
--
Mike Epprecht, Microsoft SQL Server MVP
Zurich, Switzerland
IM: mike@.epprecht.net
MVP Program: http://www.microsoft.com/mvp
Blog: http://www.msmvps.com/epprecht/
"WillAva" <WillAva@.discussions.microsoft.com> wrote in message
news:C95D1918-D841-42F9-B156-1C00A7BF8304@.microsoft.com...
> We have a Hitachi Thunder SAN to host SharePoint databases. We are
> running
> SQL server 2000 SP3 in a 2 node active/passive cluster. I have read
> articles
> stating to run diskpar to align the offset correctly with the disks to
> dramatically increase performance. I'm undecided on whether I should run
> diskpar.
> Does anybody have experience of seeing improvement using Hitachi SANs?
> There seems to be more experience with Exchange than SQL out there.
> --
> Will Robinson

diskpar and Hitachi SAN for performance

We have a Hitachi Thunder SAN to host SharePoint databases. We are running
SQL server 2000 SP3 in a 2 node active/passive cluster. I have read articles
stating to run diskpar to align the offset correctly with the disks to
dramatically increase performance. I'm undecided on whether I should run
diskpar.
Does anybody have experience of seeing improvement using Hitachi SANs?
There seems to be more experience with Exchange than SQL out there.
Will Robinson
Hi
Yes, run it. The alignment of OS blocks with the underlying SAN block does
eliminate the need for the SAN to do unnecessary IO.
Also, make sure that your formatting matches your SAN's block size. On or
Hitachi and EMC's, we format the drives with 64kb blocks, as this matches
SQL Server I/O sizes and our SAN's stripe size.
Regards
Mike Epprecht, Microsoft SQL Server MVP
Zurich, Switzerland
IM: mike@.epprecht.net
MVP Program: http://www.microsoft.com/mvp
Blog: http://www.msmvps.com/epprecht/
"WillAva" <WillAva@.discussions.microsoft.com> wrote in message
news:C95D1918-D841-42F9-B156-1C00A7BF8304@.microsoft.com...
> We have a Hitachi Thunder SAN to host SharePoint databases. We are
> running
> SQL server 2000 SP3 in a 2 node active/passive cluster. I have read
> articles
> stating to run diskpar to align the offset correctly with the disks to
> dramatically increase performance. I'm undecided on whether I should run
> diskpar.
> Does anybody have experience of seeing improvement using Hitachi SANs?
> There seems to be more experience with Exchange than SQL out there.
> --
> Will Robinson
sql

diskpar and Hitachi SAN for performance

We have a Hitachi Thunder SAN to host SharePoint databases. We are running
SQL server 2000 SP3 in a 2 node active/passive cluster. I have read article
s
stating to run diskpar to align the offset correctly with the disks to
dramatically increase performance. I'm undecided on whether I should run
diskpar.
Does anybody have experience of seeing improvement using Hitachi SANs?
There seems to be more experience with Exchange than SQL out there.
--
Will RobinsonHi
Yes, run it. The alignment of OS blocks with the underlying SAN block does
eliminate the need for the SAN to do unnecessary IO.
Also, make sure that your formatting matches your SAN's block size. On or
Hitachi and EMC's, we format the drives with 64kb blocks, as this matches
SQL Server I/O sizes and our SAN's stripe size.
Regards
--
Mike Epprecht, Microsoft SQL Server MVP
Zurich, Switzerland
IM: mike@.epprecht.net
MVP Program: http://www.microsoft.com/mvp
Blog: http://www.msmvps.com/epprecht/
"WillAva" <WillAva@.discussions.microsoft.com> wrote in message
news:C95D1918-D841-42F9-B156-1C00A7BF8304@.microsoft.com...
> We have a Hitachi Thunder SAN to host SharePoint databases. We are
> running
> SQL server 2000 SP3 in a 2 node active/passive cluster. I have read
> articles
> stating to run diskpar to align the offset correctly with the disks to
> dramatically increase performance. I'm undecided on whether I should run
> diskpar.
> Does anybody have experience of seeing improvement using Hitachi SANs?
> There seems to be more experience with Exchange than SQL out there.
> --
> Will Robinson

Disk space getting low

I have 3 disk volumes on my server. C, D, E. C=System, D=Logs, E= Data
How do I get the 2 databases to use drive D in addition to drive E for data?
I have 50 gig volume for E and I have about 9 gig free as of now. D has
only consumed 1 gig and free is 34 gig.
TIA
__StephenPre-allocate storage for the database files as desired. If you need to shrink one of the file (so
that data will be pushed to the other file), you can do it using DBCC SHRINKFILE. It will take a
while for a lot of data, though.
--
Tibor Karaszi, SQL Server MVP
http://www.karaszi.com/sqlserver/default.asp
http://www.solidqualitylearning.com/
"Stephen Russell" <srussell@.transactiongraphics.com> wrote in message
news:ugcOCCvsFHA.3040@.TK2MSFTNGP14.phx.gbl...
>I have 3 disk volumes on my server. C, D, E. C=System, D=Logs, E= Data
> How do I get the 2 databases to use drive D in addition to drive E for data? I have 50 gig volume
> for E and I have about 9 gig free as of now. D has only consumed 1 gig and free is 34 gig.
> TIA
> __Stephen
>
>

Disk space getting low

I have 3 disk volumes on my server. C, D, E. C=System, D=Logs, E= Data
How do I get the 2 databases to use drive D in addition to drive E for data?
I have 50 gig volume for E and I have about 9 gig free as of now. D has
only consumed 1 gig and free is 34 gig.
TIA
__Stephen
Pre-allocate storage for the database files as desired. If you need to shrink one of the file (so
that data will be pushed to the other file), you can do it using DBCC SHRINKFILE. It will take a
while for a lot of data, though.
Tibor Karaszi, SQL Server MVP
http://www.karaszi.com/sqlserver/default.asp
http://www.solidqualitylearning.com/
"Stephen Russell" <srussell@.transactiongraphics.com> wrote in message
news:ugcOCCvsFHA.3040@.TK2MSFTNGP14.phx.gbl...
>I have 3 disk volumes on my server. C, D, E. C=System, D=Logs, E= Data
> How do I get the 2 databases to use drive D in addition to drive E for data? I have 50 gig volume
> for E and I have about 9 gig free as of now. D has only consumed 1 gig and free is 34 gig.
> TIA
> __Stephen
>
>

Disk space getting low

I have 3 disk volumes on my server. C, D, E. C=System, D=Logs, E= Data
How do I get the 2 databases to use drive D in addition to drive E for data?
I have 50 gig volume for E and I have about 9 gig free as of now. D has
only consumed 1 gig and free is 34 gig.
TIA
__StephenPre-allocate storage for the database files as desired. If you need to shrin
k one of the file (so
that data will be pushed to the other file), you can do it using DBCC SHRINK
FILE. It will take a
while for a lot of data, though.
Tibor Karaszi, SQL Server MVP
http://www.karaszi.com/sqlserver/default.asp
http://www.solidqualitylearning.com/
"Stephen Russell" <srussell@.transactiongraphics.com> wrote in message
news:ugcOCCvsFHA.3040@.TK2MSFTNGP14.phx.gbl...
>I have 3 disk volumes on my server. C, D, E. C=System, D=Logs, E= Data
> How do I get the 2 databases to use drive D in addition to drive E for dat
a? I have 50 gig volume
> for E and I have about 9 gig free as of now. D has only consumed 1 gig a
nd free is 34 gig.
> TIA
> __Stephen
>
>sql

Disk permission to move SQL 2005 databases too...

I have a server with SQL 2000 and a name instance of SQL 2005, I am trying
to use the copy wizard to move databases from SQL2000 to SQL2005, when I do
this and to try to change the drive letters to my D: drive for the logs and
E: drive for the database, it goes through the process and fails. So I have
tried it again this time to the default location that SQL 2005 wants, which
is on the C: drive - of course this is not acceptable, but it works that
way. I figure it is a NTFS / permissions issue. But what permissions do I
need to setup on the other drive D: and E: to get this to work properly,
anyone please help me.
Thanks,
Andres
andres.perales@.mclaneat.com
Hi
Take a look at RESTORE command WITH MOVE option in the BOL
"Andres Perales" <andres@.andresperales.com> wrote in message
news:eu%23YtAyIHHA.1248@.TK2MSFTNGP03.phx.gbl...
>I have a server with SQL 2000 and a name instance of SQL 2005, I am trying
>to use the copy wizard to move databases from SQL2000 to SQL2005, when I do
>this and to try to change the drive letters to my D: drive for the logs and
>E: drive for the database, it goes through the process and fails. So I
>have tried it again this time to the default location that SQL 2005 wants,
>which is on the C: drive - of course this is not acceptable, but it works
>that way. I figure it is a NTFS / permissions issue. But what permissions
>do I need to setup on the other drive D: and E: to get this to work
>properly, anyone please help me.
> Thanks,
> Andres
> andres.perales@.mclaneat.com
>
>

Disk permission to move SQL 2005 databases too...

I have a server with SQL 2000 and a name instance of SQL 2005, I am trying
to use the copy wizard to move databases from SQL2000 to SQL2005, when I do
this and to try to change the drive letters to my D: drive for the logs and
E: drive for the database, it goes through the process and fails. So I have
tried it again this time to the default location that SQL 2005 wants, which
is on the C: drive - of course this is not acceptable, but it works that
way. I figure it is a NTFS / permissions issue. But what permissions do I
need to setup on the other drive D: and E: to get this to work properly,
anyone please help me.
Thanks,
Andres
andres.perales@.mclaneat.comHi
Take a look at RESTORE command WITH MOVE option in the BOL
"Andres Perales" <andres@.andresperales.com> wrote in message
news:eu%23YtAyIHHA.1248@.TK2MSFTNGP03.phx.gbl...
>I have a server with SQL 2000 and a name instance of SQL 2005, I am trying
>to use the copy wizard to move databases from SQL2000 to SQL2005, when I do
>this and to try to change the drive letters to my D: drive for the logs and
>E: drive for the database, it goes through the process and fails. So I
>have tried it again this time to the default location that SQL 2005 wants,
>which is on the C: drive - of course this is not acceptable, but it works
>that way. I figure it is a NTFS / permissions issue. But what permissions
>do I need to setup on the other drive D: and E: to get this to work
>properly, anyone please help me.
> Thanks,
> Andres
> andres.perales@.mclaneat.com
>
>|||Assuming the RESTORE command is correct (you have used the MOVE options corr
ectly):
The account used by the SQL Server service need create file and write permis
sions on the directory.
Tibor Karaszi, SQL Server MVP
http://www.karaszi.com/sqlserver/default.asp
http://www.solidqualitylearning.com/
"Andres Perales" <andres@.andresperales.com> wrote in message
news:eu%23YtAyIHHA.1248@.TK2MSFTNGP03.phx.gbl...
>I have a server with SQL 2000 and a name instance of SQL 2005, I am trying
to use the copy wizard
>to move databases from SQL2000 to SQL2005, when I do this and to try to cha
nge the drive letters to
>my D: drive for the logs and E: drive for the database, it goes through the
process and fails. So
>I have tried it again this time to the default location that SQL 2005 wants
, which is on the C:
>drive - of course this is not acceptable, but it works that way. I figure
it is a NTFS /
>permissions issue. But what permissions do I need to setup on the other dri
ve D: and E: to get this
>to work properly, anyone please help me.
> Thanks,
> Andres
> andres.perales@.mclaneat.com
>
>

Disk permission to move SQL 2005 databases too...

I have a server with SQL 2000 and a name instance of SQL 2005, I am trying
to use the copy wizard to move databases from SQL2000 to SQL2005, when I do
this and to try to change the drive letters to my D: drive for the logs and
E: drive for the database, it goes through the process and fails. So I have
tried it again this time to the default location that SQL 2005 wants, which
is on the C: drive - of course this is not acceptable, but it works that
way. I figure it is a NTFS / permissions issue. But what permissions do I
need to setup on the other drive D: and E: to get this to work properly,
anyone please help me.
Thanks,
Andres
andres.perales@.mclaneat.comHi
Take a look at RESTORE command WITH MOVE option in the BOL
"Andres Perales" <andres@.andresperales.com> wrote in message
news:eu%23YtAyIHHA.1248@.TK2MSFTNGP03.phx.gbl...
>I have a server with SQL 2000 and a name instance of SQL 2005, I am trying
>to use the copy wizard to move databases from SQL2000 to SQL2005, when I do
>this and to try to change the drive letters to my D: drive for the logs and
>E: drive for the database, it goes through the process and fails. So I
>have tried it again this time to the default location that SQL 2005 wants,
>which is on the C: drive - of course this is not acceptable, but it works
>that way. I figure it is a NTFS / permissions issue. But what permissions
>do I need to setup on the other drive D: and E: to get this to work
>properly, anyone please help me.
> Thanks,
> Andres
> andres.perales@.mclaneat.com
>
>|||Assuming the RESTORE command is correct (you have used the MOVE options correctly):
The account used by the SQL Server service need create file and write permissions on the directory.
--
Tibor Karaszi, SQL Server MVP
http://www.karaszi.com/sqlserver/default.asp
http://www.solidqualitylearning.com/
"Andres Perales" <andres@.andresperales.com> wrote in message
news:eu%23YtAyIHHA.1248@.TK2MSFTNGP03.phx.gbl...
>I have a server with SQL 2000 and a name instance of SQL 2005, I am trying to use the copy wizard
>to move databases from SQL2000 to SQL2005, when I do this and to try to change the drive letters to
>my D: drive for the logs and E: drive for the database, it goes through the process and fails. So
>I have tried it again this time to the default location that SQL 2005 wants, which is on the C:
>drive - of course this is not acceptable, but it works that way. I figure it is a NTFS /
>permissions issue. But what permissions do I need to setup on the other drive D: and E: to get this
>to work properly, anyone please help me.
> Thanks,
> Andres
> andres.perales@.mclaneat.com
>
>sql

Disk Layout from h/w perspective

We usually have our databases comprise of 2 data files and one log file
Is it best to have these files on their own array controller or even on
different channels on the same array controller ?
Whats ideal ?
How do organizations lay out there databases i.e. data and log files along
with the tempdb and backup files,etc.
Would love to hear in terms of array controllers,etc..
You could tell me in terms of an HP or a Dell server..Doesnt matter.. Just
seeking for advices.Ideally you would have your own controller for each with different raid
arrays -raid 10 for the logs and raid 5 for the data. If your work load is
write intensive (over 20% writes) I would make both arrays raid 10.
Hilary Cotter
Director of Text Mining and Database Strategy
RelevantNOISE.Com - Dedicated to mining blogs for business intelligence.
This posting is my own and doesn't necessarily represent RelevantNoise's
positions, strategies or opinions.
Looking for a SQL Server replication book?
http://www.nwsu.com/0974973602.html
Looking for a FAQ on Indexing Services/SQL FTS
http://www.indexserverfaq.com
"Hassan" <Hassan@.hotmail.com> wrote in message
news:Odg69QpPGHA.3984@.TK2MSFTNGP14.phx.gbl...
> We usually have our databases comprise of 2 data files and one log file
> Is it best to have these files on their own array controller or even on
> different channels on the same array controller ?
> Whats ideal ?
> How do organizations lay out there databases i.e. data and log files along
> with the tempdb and backup files,etc.
> Would love to hear in terms of array controllers,etc..
> You could tell me in terms of an HP or a Dell server..Doesnt matter.. Just
> seeking for advices.
>|||So even if a controller has 2-4 channels, you would not prefer to have
arrays hooked to different channels on the same array controller ?
"Hilary Cotter" <hilary.cotter@.gmail.com> wrote in message
news:O8TYu0qPGHA.3728@.tk2msftngp13.phx.gbl...
> Ideally you would have your own controller for each with different raid
> arrays -raid 10 for the logs and raid 5 for the data. If your work load is
> write intensive (over 20% writes) I would make both arrays raid 10.
> --
> Hilary Cotter
> Director of Text Mining and Database Strategy
> RelevantNOISE.Com - Dedicated to mining blogs for business intelligence.
> This posting is my own and doesn't necessarily represent RelevantNoise's
> positions, strategies or opinions.
> Looking for a SQL Server replication book?
> http://www.nwsu.com/0974973602.html
> Looking for a FAQ on Indexing Services/SQL FTS
> http://www.indexserverfaq.com
>
> "Hassan" <Hassan@.hotmail.com> wrote in message
> news:Odg69QpPGHA.3984@.TK2MSFTNGP14.phx.gbl...
>

Disk Layout from h/w perspective

We usually have our databases comprise of 2 data files and one log file
Is it best to have these files on their own array controller or even on
different channels on the same array controller ?
Whats ideal ?
How do organizations lay out there databases i.e. data and log files along
with the tempdb and backup files,etc.
Would love to hear in terms of array controllers,etc..
You could tell me in terms of an HP or a Dell server..Doesnt matter.. Just
seeking for advices.
Ideally you would have your own controller for each with different raid
arrays -raid 10 for the logs and raid 5 for the data. If your work load is
write intensive (over 20% writes) I would make both arrays raid 10.
Hilary Cotter
Director of Text Mining and Database Strategy
RelevantNOISE.Com - Dedicated to mining blogs for business intelligence.
This posting is my own and doesn't necessarily represent RelevantNoise's
positions, strategies or opinions.
Looking for a SQL Server replication book?
http://www.nwsu.com/0974973602.html
Looking for a FAQ on Indexing Services/SQL FTS
http://www.indexserverfaq.com
"Hassan" <Hassan@.hotmail.com> wrote in message
news:Odg69QpPGHA.3984@.TK2MSFTNGP14.phx.gbl...
> We usually have our databases comprise of 2 data files and one log file
> Is it best to have these files on their own array controller or even on
> different channels on the same array controller ?
> Whats ideal ?
> How do organizations lay out there databases i.e. data and log files along
> with the tempdb and backup files,etc.
> Would love to hear in terms of array controllers,etc..
> You could tell me in terms of an HP or a Dell server..Doesnt matter.. Just
> seeking for advices.
>
|||So even if a controller has 2-4 channels, you would not prefer to have
arrays hooked to different channels on the same array controller ?
"Hilary Cotter" <hilary.cotter@.gmail.com> wrote in message
news:O8TYu0qPGHA.3728@.tk2msftngp13.phx.gbl...
> Ideally you would have your own controller for each with different raid
> arrays -raid 10 for the logs and raid 5 for the data. If your work load is
> write intensive (over 20% writes) I would make both arrays raid 10.
> --
> Hilary Cotter
> Director of Text Mining and Database Strategy
> RelevantNOISE.Com - Dedicated to mining blogs for business intelligence.
> This posting is my own and doesn't necessarily represent RelevantNoise's
> positions, strategies or opinions.
> Looking for a SQL Server replication book?
> http://www.nwsu.com/0974973602.html
> Looking for a FAQ on Indexing Services/SQL FTS
> http://www.indexserverfaq.com
>
> "Hassan" <Hassan@.hotmail.com> wrote in message
> news:Odg69QpPGHA.3984@.TK2MSFTNGP14.phx.gbl...
>

Disk Layout from h/w perspective

We usually have our databases comprise of 2 data files and one log file
Is it best to have these files on their own array controller or even on
different channels on the same array controller ?
Whats ideal ?
How do organizations lay out there databases i.e. data and log files along
with the tempdb and backup files,etc.
Would love to hear in terms of array controllers,etc..
You could tell me in terms of an HP or a Dell server..Doesnt matter.. Just
seeking for advices.Ideally you would have your own controller for each with different raid
arrays -raid 10 for the logs and raid 5 for the data. If your work load is
write intensive (over 20% writes) I would make both arrays raid 10.
--
Hilary Cotter
Director of Text Mining and Database Strategy
RelevantNOISE.Com - Dedicated to mining blogs for business intelligence.
This posting is my own and doesn't necessarily represent RelevantNoise's
positions, strategies or opinions.
Looking for a SQL Server replication book?
http://www.nwsu.com/0974973602.html
Looking for a FAQ on Indexing Services/SQL FTS
http://www.indexserverfaq.com
"Hassan" <Hassan@.hotmail.com> wrote in message
news:Odg69QpPGHA.3984@.TK2MSFTNGP14.phx.gbl...
> We usually have our databases comprise of 2 data files and one log file
> Is it best to have these files on their own array controller or even on
> different channels on the same array controller ?
> Whats ideal ?
> How do organizations lay out there databases i.e. data and log files along
> with the tempdb and backup files,etc.
> Would love to hear in terms of array controllers,etc..
> You could tell me in terms of an HP or a Dell server..Doesnt matter.. Just
> seeking for advices.
>|||So even if a controller has 2-4 channels, you would not prefer to have
arrays hooked to different channels on the same array controller ?
"Hilary Cotter" <hilary.cotter@.gmail.com> wrote in message
news:O8TYu0qPGHA.3728@.tk2msftngp13.phx.gbl...
> Ideally you would have your own controller for each with different raid
> arrays -raid 10 for the logs and raid 5 for the data. If your work load is
> write intensive (over 20% writes) I would make both arrays raid 10.
> --
> Hilary Cotter
> Director of Text Mining and Database Strategy
> RelevantNOISE.Com - Dedicated to mining blogs for business intelligence.
> This posting is my own and doesn't necessarily represent RelevantNoise's
> positions, strategies or opinions.
> Looking for a SQL Server replication book?
> http://www.nwsu.com/0974973602.html
> Looking for a FAQ on Indexing Services/SQL FTS
> http://www.indexserverfaq.com
>
> "Hassan" <Hassan@.hotmail.com> wrote in message
> news:Odg69QpPGHA.3984@.TK2MSFTNGP14.phx.gbl...
>> We usually have our databases comprise of 2 data files and one log file
>> Is it best to have these files on their own array controller or even on
>> different channels on the same array controller ?
>> Whats ideal ?
>> How do organizations lay out there databases i.e. data and log files
>> along with the tempdb and backup files,etc.
>> Would love to hear in terms of array controllers,etc..
>> You could tell me in terms of an HP or a Dell server..Doesnt matter..
>> Just seeking for advices.
>

disk fragmentation

I have a Dell PowerEdge 2850 with Windows 2003 server. 2 disk drives with RAID. My databases are fragmented on the drive and I need to defrag the drive at least once a week. My database files are fragmented. Defragger cleans up the files but as soon as I start running processes again, the files fragment and system response time suffers.

What can I do to keep the files from fragmenting?

calculate the database growth

and set the file increment in the db option

bigger than that. i meann just a little bigger

|||

Question : does file fragmentation really impact the performance of a DB ?

I mean : by construction, the data in files are fragmented, and access to data in DB always require a lot of disk seek. Sequential access through files should be marginal. So, fragmentation of the whole file should not imply a big performance impact.

Am I correct ?

|||

How are you measuring the fragmentation?

There are two types of fragmentation here:

1) The normal filesystem fragmentation of the database files. This should have minimal to nil impact unless you do a lot of table-scans. On the other hand, you shouldn't be getting this sort of fragmentation unless you are constantly growing your database. Far better to size it for growth initially than to allow it to grow incrementally.

2) Internal fragmentation of the information within the database files (as measured by commands like DBCC SHOWCONTIG). THis has nothing to do with the physical files being fragmented on disk, and is resolved by using SQL techniques such as DBCC INDEXDEFRAG or ALTER INDEX REBUILD.

Disk Failure on Raid 5

Can a disk failure on Raid 5 cause torn pages? It actually did cause
torn pages on several databases for us, so I am wondering if we have
some kind of configuration problem.
Thanks
A torn page basically reads the last two bits of a page that is written to
disk. If you have a hardware issue as the page is written to disk you always
have the potential to have part of the data written and part not. I think
anytime you have a disk failure you run the risk of a torn page.
Andrew J. Kelly SQL MVP
"Dave" <daveg.01@.gmail.com> wrote in message
news:1136847162.322252.52170@.o13g2000cwo.googlegro ups.com...
> Can a disk failure on Raid 5 cause torn pages? It actually did cause
> torn pages on several databases for us, so I am wondering if we have
> some kind of configuration problem.
> Thanks
>
|||Is there anything we could do to prevent this or is it just a fact of
life?
I guess I don't understand why the data page would not have been
written correctly to the redundant drive.
|||I'm no storage expert, but I would ask the storage vendor whether the RAID system fulfils Write
ordering and other aspects mentioned in
http://www.microsoft.com/technet/pro...basics.mspx.in case of a drive
failure.
Tibor Karaszi, SQL Server MVP
http://www.karaszi.com/sqlserver/default.asp
http://www.solidqualitylearning.com/
Blog: http://solidqualitylearning.com/blogs/tibor/
"Dave" <daveg.01@.gmail.com> wrote in message
news:1136912372.389395.67820@.g47g2000cwa.googlegro ups.com...
> Is there anything we could do to prevent this or is it just a fact of
> life?
> I guess I don't understand why the data page would not have been
> written correctly to the redundant drive.
>
|||Well a RAID 5 does not actually have a redundant drive. All the drives are
written to with a small piece of the data. One of the drives holds the
parity while the others each get a piece of the actual data. So if any one
piece is missing it can rebuild the data with the parity. But that does not
mean you can not get corruption on the write especially during a hardware
failure. I won't claim to know how the drive controllers work internally and
how they each do their stuff. So I am not sure other than ensuring you have
good name equipment and all in proper working order. Especially the UPS.
Andrew J. Kelly SQL MVP
"Dave" <daveg.01@.gmail.com> wrote in message
news:1136912372.389395.67820@.g47g2000cwa.googlegro ups.com...
> Is there anything we could do to prevent this or is it just a fact of
> life?
> I guess I don't understand why the data page would not have been
> written correctly to the redundant drive.
>
|||Guys, I guess I am just not getting it. I thought that RAID 5 was
redundant, meaning it should not be affected by a disk failure. The
data should be stored on 2 drives right? So how can you get torn page
errors when a disk fails?
Can someone please step me though a scenario of how data can be
corrupted with a RAID 5 disk failure?
|||No that is not how a RAID 5 works. If you have 4 drives in a RAID 5 you
will essentially split the data into 3 pieces. One of each of the pieces
will go onto 3 of the drives and a parity is calculated and placed on the
fourth drive. Each time you write to the drive array this is repeated but
the parity moves around so it is not always on the same drive. Under normal
conditions when you read the data the parity is not used and the whole data
block is created by piecing the three pieces back together. In the event of
a single disk failure the controller can read the two remaining good pieces
and using the parity recreate the third to get the data back. A Raid 5 does
not store the data twice. But even if it did that still does not prevent
torn pages. As I mentioned a torn page occurs when for some reason (usually
hardware related) the last two bits on a page did not get written properly
or at all. This can happen when the driver thinks it wrote the page
properly but the hardware didn't. A Raid 5 array does not claim to stop this
from occurring. That is why backups are so important. You can not protect
your data 100% with a Raid array.
Andrew J. Kelly SQL MVP
"Dave" <daveg.01@.gmail.com> wrote in message
news:1137002846.251710.290370@.g44g2000cwa.googlegr oups.com...
> Guys, I guess I am just not getting it. I thought that RAID 5 was
> redundant, meaning it should not be affected by a disk failure. The
> data should be stored on 2 drives right? So how can you get torn page
> errors when a disk fails?
> Can someone please step me though a scenario of how data can be
> corrupted with a RAID 5 disk failure?
>
|||Thanks, that helps a little.
I am still having a hard time grasping parity.
I will use Raid 3 for simplicity.
Disk 1: 00000000
Disk 2: 11111111
Disk 3: ??
On Raid 3, if Disk 3 stores parity data, what would it store? I
don't understand how one drive could store enough data to rebuild
Disk 1 or Disk 2.
|||This should explain Parity:
http://www.pcguide.com/ref/hdd/perf/...nParity-c.html
This shows how raid 3 (and others) use parity.
http://www.storagereview.com/guide20...gleLevel3.html
This tells you why you may want to consider something other than RAID 5.
http://www.baarf.com/
Andrew J. Kelly SQL MVP
"Dave" <daveg.01@.gmail.com> wrote in message
news:1137006115.234760.166690@.g44g2000cwa.googlegr oups.com...
> Thanks, that helps a little.
> I am still having a hard time grasping parity.
> I will use Raid 3 for simplicity.
> Disk 1: 00000000
> Disk 2: 11111111
> Disk 3: ??
> On Raid 3, if Disk 3 stores parity data, what would it store? I
> don't understand how one drive could store enough data to rebuild
> Disk 1 or Disk 2.
>
|||How would RAID 10 affect this scenerio?
sql

Disk Failure on Raid 5

Can a disk failure on Raid 5 cause torn pages? It actually did cause
torn pages on several databases for us, so I am wondering if we have
some kind of configuration problem.
ThanksA torn page basically reads the last two bits of a page that is written to
disk. If you have a hardware issue as the page is written to disk you always
have the potential to have part of the data written and part not. I think
anytime you have a disk failure you run the risk of a torn page.
--
Andrew J. Kelly SQL MVP
"Dave" <daveg.01@.gmail.com> wrote in message
news:1136847162.322252.52170@.o13g2000cwo.googlegroups.com...
> Can a disk failure on Raid 5 cause torn pages? It actually did cause
> torn pages on several databases for us, so I am wondering if we have
> some kind of configuration problem.
> Thanks
>|||Is there anything we could do to prevent this or is it just a fact of
life?
I guess I don't understand why the data page would not have been
written correctly to the redundant drive.|||I'm no storage expert, but I would ask the storage vendor whether the RAID system fulfils Write
ordering and other aspects mentioned in
http://www.microsoft.com/technet/prodtechnol/sql/2000/maintain/sqlIObasics.mspx.in case of a drive
failure.
--
Tibor Karaszi, SQL Server MVP
http://www.karaszi.com/sqlserver/default.asp
http://www.solidqualitylearning.com/
Blog: http://solidqualitylearning.com/blogs/tibor/
"Dave" <daveg.01@.gmail.com> wrote in message
news:1136912372.389395.67820@.g47g2000cwa.googlegroups.com...
> Is there anything we could do to prevent this or is it just a fact of
> life?
> I guess I don't understand why the data page would not have been
> written correctly to the redundant drive.
>|||Well a RAID 5 does not actually have a redundant drive. All the drives are
written to with a small piece of the data. One of the drives holds the
parity while the others each get a piece of the actual data. So if any one
piece is missing it can rebuild the data with the parity. But that does not
mean you can not get corruption on the write especially during a hardware
failure. I won't claim to know how the drive controllers work internally and
how they each do their stuff. So I am not sure other than ensuring you have
good name equipment and all in proper working order. Especially the UPS.
--
Andrew J. Kelly SQL MVP
"Dave" <daveg.01@.gmail.com> wrote in message
news:1136912372.389395.67820@.g47g2000cwa.googlegroups.com...
> Is there anything we could do to prevent this or is it just a fact of
> life?
> I guess I don't understand why the data page would not have been
> written correctly to the redundant drive.
>|||Guys, I guess I am just not getting it. I thought that RAID 5 was
redundant, meaning it should not be affected by a disk failure. The
data should be stored on 2 drives right? So how can you get torn page
errors when a disk fails?
Can someone please step me though a scenario of how data can be
corrupted with a RAID 5 disk failure?|||No that is not how a RAID 5 works. If you have 4 drives in a RAID 5 you
will essentially split the data into 3 pieces. One of each of the pieces
will go onto 3 of the drives and a parity is calculated and placed on the
fourth drive. Each time you write to the drive array this is repeated but
the parity moves around so it is not always on the same drive. Under normal
conditions when you read the data the parity is not used and the whole data
block is created by piecing the three pieces back together. In the event of
a single disk failure the controller can read the two remaining good pieces
and using the parity recreate the third to get the data back. A Raid 5 does
not store the data twice. But even if it did that still does not prevent
torn pages. As I mentioned a torn page occurs when for some reason (usually
hardware related) the last two bits on a page did not get written properly
or at all. This can happen when the driver thinks it wrote the page
properly but the hardware didn't. A Raid 5 array does not claim to stop this
from occurring. That is why backups are so important. You can not protect
your data 100% with a Raid array.
--
Andrew J. Kelly SQL MVP
"Dave" <daveg.01@.gmail.com> wrote in message
news:1137002846.251710.290370@.g44g2000cwa.googlegroups.com...
> Guys, I guess I am just not getting it. I thought that RAID 5 was
> redundant, meaning it should not be affected by a disk failure. The
> data should be stored on 2 drives right? So how can you get torn page
> errors when a disk fails?
> Can someone please step me though a scenario of how data can be
> corrupted with a RAID 5 disk failure?
>|||Thanks, that helps a little.
I am still having a hard time grasping parity.
I will use Raid 3 for simplicity.
Disk 1: 00000000
Disk 2: 11111111
Disk 3: ''
On Raid 3, if Disk 3 stores parity data, what would it store? I
don't understand how one drive could store enough data to rebuild
Disk 1 or Disk 2.|||This should explain Parity:
http://www.pcguide.com/ref/hdd/perf/raid/concepts/genParity-c.html
This shows how raid 3 (and others) use parity.
http://www.storagereview.com/guide2000/ref/hdd/perf/raid/levels/singleLevel3.html
This tells you why you may want to consider something other than RAID 5.
http://www.baarf.com/
Andrew J. Kelly SQL MVP
"Dave" <daveg.01@.gmail.com> wrote in message
news:1137006115.234760.166690@.g44g2000cwa.googlegroups.com...
> Thanks, that helps a little.
> I am still having a hard time grasping parity.
> I will use Raid 3 for simplicity.
> Disk 1: 00000000
> Disk 2: 11111111
> Disk 3: ''
> On Raid 3, if Disk 3 stores parity data, what would it store? I
> don't understand how one drive could store enough data to rebuild
> Disk 1 or Disk 2.
>|||How would RAID 10 affect this scenerio?|||I don't think it would matter what raid level it was. While Raid 10 does not
use parity it still writes to the disk and any write has the potential to
have a torn page.
--
Andrew J. Kelly SQL MVP
"JLA" <info@.jlaenterprises-dot-com.no-spam.invalid> wrote in message
news:43c5acee$0$17777$c3e8da3@.news.astraweb.com...
> How would RAID 10 affect this scenerio?
>|||Thanks! that was some good reading!
I think I am going to push for Raid 10. :-)

Disk Failure on Raid 5

Can a disk failure on Raid 5 cause torn pages? It actually did cause
torn pages on several databases for us, so I am wondering if we have
some kind of configuration problem.
ThanksA torn page basically reads the last two bits of a page that is written to
disk. If you have a hardware issue as the page is written to disk you always
have the potential to have part of the data written and part not. I think
anytime you have a disk failure you run the risk of a torn page.
Andrew J. Kelly SQL MVP
"Dave" <daveg.01@.gmail.com> wrote in message
news:1136847162.322252.52170@.o13g2000cwo.googlegroups.com...
> Can a disk failure on Raid 5 cause torn pages? It actually did cause
> torn pages on several databases for us, so I am wondering if we have
> some kind of configuration problem.
> Thanks
>|||Is there anything we could do to prevent this or is it just a fact of
life?
I guess I don't understand why the data page would not have been
written correctly to the redundant drive.|||I'm no storage expert, but I would ask the storage vendor whether the RAID s
ystem fulfils Write
ordering and other aspects mentioned in
http://www.microsoft.com/technet/pr...mspx.in
case of a drive
failure.
Tibor Karaszi, SQL Server MVP
http://www.karaszi.com/sqlserver/default.asp
http://www.solidqualitylearning.com/
Blog: http://solidqualitylearning.com/blogs/tibor/
"Dave" <daveg.01@.gmail.com> wrote in message
news:1136912372.389395.67820@.g47g2000cwa.googlegroups.com...
> Is there anything we could do to prevent this or is it just a fact of
> life?
> I guess I don't understand why the data page would not have been
> written correctly to the redundant drive.
>|||Well a RAID 5 does not actually have a redundant drive. All the drives are
written to with a small piece of the data. One of the drives holds the
parity while the others each get a piece of the actual data. So if any one
piece is missing it can rebuild the data with the parity. But that does not
mean you can not get corruption on the write especially during a hardware
failure. I won't claim to know how the drive controllers work internally and
how they each do their stuff. So I am not sure other than ensuring you have
good name equipment and all in proper working order. Especially the UPS.
Andrew J. Kelly SQL MVP
"Dave" <daveg.01@.gmail.com> wrote in message
news:1136912372.389395.67820@.g47g2000cwa.googlegroups.com...
> Is there anything we could do to prevent this or is it just a fact of
> life?
> I guess I don't understand why the data page would not have been
> written correctly to the redundant drive.
>|||Guys, I guess I am just not getting it. I thought that RAID 5 was
redundant, meaning it should not be affected by a disk failure. The
data should be stored on 2 drives right? So how can you get torn page
errors when a disk fails?
Can someone please step me though a scenario of how data can be
corrupted with a RAID 5 disk failure?|||No that is not how a RAID 5 works. If you have 4 drives in a RAID 5 you
will essentially split the data into 3 pieces. One of each of the pieces
will go onto 3 of the drives and a parity is calculated and placed on the
fourth drive. Each time you write to the drive array this is repeated but
the parity moves around so it is not always on the same drive. Under normal
conditions when you read the data the parity is not used and the whole data
block is created by piecing the three pieces back together. In the event of
a single disk failure the controller can read the two remaining good pieces
and using the parity recreate the third to get the data back. A Raid 5 does
not store the data twice. But even if it did that still does not prevent
torn pages. As I mentioned a torn page occurs when for some reason (usually
hardware related) the last two bits on a page did not get written properly
or at all. This can happen when the driver thinks it wrote the page
properly but the hardware didn't. A Raid 5 array does not claim to stop this
from occurring. That is why backups are so important. You can not protect
your data 100% with a Raid array.
Andrew J. Kelly SQL MVP
"Dave" <daveg.01@.gmail.com> wrote in message
news:1137002846.251710.290370@.g44g2000cwa.googlegroups.com...
> Guys, I guess I am just not getting it. I thought that RAID 5 was
> redundant, meaning it should not be affected by a disk failure. The
> data should be stored on 2 drives right? So how can you get torn page
> errors when a disk fails?
> Can someone please step me though a scenario of how data can be
> corrupted with a RAID 5 disk failure?
>|||Thanks, that helps a little.
I am still having a hard time grasping parity.
I will use Raid 3 for simplicity.
Disk 1: 00000000
Disk 2: 11111111
Disk 3: ''
On Raid 3, if Disk 3 stores parity data, what would it store? I
don't understand how one drive could store enough data to rebuild
Disk 1 or Disk 2.|||This should explain Parity:
http://www.pcguide.com/ref/hdd/perf...enParity-c.html
This shows how raid 3 (and others) use parity.
http://www.storagereview.com/guide2.../www.baarf.com/
Andrew J. Kelly SQL MVP
"Dave" <daveg.01@.gmail.com> wrote in message
news:1137006115.234760.166690@.g44g2000cwa.googlegroups.com...
> Thanks, that helps a little.
> I am still having a hard time grasping parity.
> I will use Raid 3 for simplicity.
> Disk 1: 00000000
> Disk 2: 11111111
> Disk 3: ''
> On Raid 3, if Disk 3 stores parity data, what would it store? I
> don't understand how one drive could store enough data to rebuild
> Disk 1 or Disk 2.
>|||How would RAID 10 affect this scenerio?

Disk Error

I am getting this Error when i am doing a SELECT INTO Operation in a lot of
my databases on SQL SServer 2000
Pls help
Server: Msg 823, Level 24, State 2, Line 1
I/O error 1450(Insufficient system resources exist to complete the requested
service.) detected during read at offset 0x0000067c780000 in file
'K:\DCCTDG01\DCCTDG01_data2.ndf'.
ODBC: Msg 0, Level 16, State 1
Communication link failure
Connection Broken
See if these are related:
http://support.microsoft.com/default...&Product=sql2k
http://support.microsoft.com/default...&Product=sql2k
Andrew J. Kelly SQL MVP
"Sanjay" <Sanjay@.discussions.microsoft.com> wrote in message
news:CB67EA77-EE46-4872-A933-3D2874FD2CAF@.microsoft.com...
> I am getting this Error when i am doing a SELECT INTO Operation in a lot
of
> my databases on SQL SServer 2000
> Pls help
> Server: Msg 823, Level 24, State 2, Line 1
> I/O error 1450(Insufficient system resources exist to complete the
requested
> service.) detected during read at offset 0x0000067c780000 in file
> 'K:\DCCTDG01\DCCTDG01_data2.ndf'.
> ODBC: Msg 0, Level 16, State 1
> Communication link failure
> Connection Broken
>

Disk Error

I am getting this Error when i am doing a SELECT INTO Operation in a lot of
my databases on SQL SServer 2000
Pls help
Server: Msg 823, Level 24, State 2, Line 1
I/O error 1450(Insufficient system resources exist to complete the requested
service.) detected during read at offset 0x0000067c780000 in file
'K:\DCCTDG01\DCCTDG01_data2.ndf'.
ODBC: Msg 0, Level 16, State 1
Communication link failure
Connection BrokenSee if these are related:
http://support.microsoft.com/default.aspx?scid=kb;en-us;828339&Product=sql2k
http://support.microsoft.com/default.aspx?scid=kb;en-us;826433&Product=sql2k
Andrew J. Kelly SQL MVP
"Sanjay" <Sanjay@.discussions.microsoft.com> wrote in message
news:CB67EA77-EE46-4872-A933-3D2874FD2CAF@.microsoft.com...
> I am getting this Error when i am doing a SELECT INTO Operation in a lot
of
> my databases on SQL SServer 2000
> Pls help
> Server: Msg 823, Level 24, State 2, Line 1
> I/O error 1450(Insufficient system resources exist to complete the
requested
> service.) detected during read at offset 0x0000067c780000 in file
> 'K:\DCCTDG01\DCCTDG01_data2.ndf'.
> ODBC: Msg 0, Level 16, State 1
> Communication link failure
> Connection Broken
>

Disk defragmentation on SQLserver

SQLserver 200 SP3 running on Win2000
I check disk D: where all the databases reside and found that it is heavily
fragmented. The list of most fragmented files include some important
database (MDF) files.
I would like to defragment the disk but also concerned about possible
problem with the databases in question since they are up and running during
the defragmentation process.
What's a safe procedure to perform defragmentation on the the disk and how
to reduce fragment in the furture?
Any suggestion is greatly appreciated.
Bill
First off always make sure you have FULL and tested backups before
attempting something like that. While some vendors state they can defrag
the sql files while running I personally would not trust my data to it. If
you want to prevent fragmentation in the first place you should always start
with a clean disk and each time you add a new database you should do the
following:
One at a time:
1. Create the database with the files at say 10MB in size. (this is so you
can always shrink it down later if need be)
2. Immediately after creating the database, alter the database and grow
each file to the size you think you will need for the next year or two
allowing plenty of room for free space in each file.
If you do that for each database as you create them the files will be
contiguous on disk and there will be no need to defrag them in the future
unless you srink or grow them again.
Andrew J. Kelly SQL MVP
"Bill Nguyen" <billn_nospam_please@.jaco.com> wrote in message
news:%2368scSPcEHA.2520@.TK2MSFTNGP12.phx.gbl...
> SQLserver 200 SP3 running on Win2000
> I check disk D: where all the databases reside and found that it is
heavily
> fragmented. The list of most fragmented files include some important
> database (MDF) files.
> I would like to defragment the disk but also concerned about possible
> problem with the databases in question since they are up and running
during
> the defragmentation process.
> What's a safe procedure to perform defragmentation on the the disk and how
> to reduce fragment in the furture?
> Any suggestion is greatly appreciated.
> Bill
>

Disk defragmentation on SQLserver

SQLserver 200 SP3 running on Win2000
I check disk D: where all the databases reside and found that it is heavily
fragmented. The list of most fragmented files include some important
database (MDF) files.
I would like to defragment the disk but also concerned about possible
problem with the databases in question since they are up and running during
the defragmentation process.
What's a safe procedure to perform defragmentation on the the disk and how
to reduce fragment in the furture?
Any suggestion is greatly appreciated.
BillFirst off always make sure you have FULL and tested backups before
attempting something like that. While some vendors state they can defrag
the sql files while running I personally would not trust my data to it. If
you want to prevent fragmentation in the first place you should always start
with a clean disk and each time you add a new database you should do the
following:
One at a time:
1. Create the database with the files at say 10MB in size. (this is so you
can always shrink it down later if need be)
2. Immediately after creating the database, alter the database and grow
each file to the size you think you will need for the next year or two
allowing plenty of room for free space in each file.
If you do that for each database as you create them the files will be
contiguous on disk and there will be no need to defrag them in the future
unless you srink or grow them again.
--
Andrew J. Kelly SQL MVP
"Bill Nguyen" <billn_nospam_please@.jaco.com> wrote in message
news:%2368scSPcEHA.2520@.TK2MSFTNGP12.phx.gbl...
> SQLserver 200 SP3 running on Win2000
> I check disk D: where all the databases reside and found that it is
heavily
> fragmented. The list of most fragmented files include some important
> database (MDF) files.
> I would like to defragment the disk but also concerned about possible
> problem with the databases in question since they are up and running
during
> the defragmentation process.
> What's a safe procedure to perform defragmentation on the the disk and how
> to reduce fragment in the furture?
> Any suggestion is greatly appreciated.
> Bill
>