Monday, February 20, 2012

partitions

Hi,
I have a question in the middle beetween Windows and SQL.
I have RAID 5 system and then I can put SQL database and log file where i
want...
But..
Can be important create more logical partitions in RAID system for improve
defrag efficiency?
Example: I have only one database in SQL. I create a system partition C, a
database partition D and a log partition E.
Can I have better performance putting database in D and log in E?
Thank's a lot.. and sotty for my english..
Andrea
Since the drives are all a single Raid 5 you will not gain any performance by
spreading the data to the D drive and logs to the E drive.
"Rusty73" wrote:

> Hi,
> I have a question in the middle beetween Windows and SQL.
> I have RAID 5 system and then I can put SQL database and log file where i
> want...
> But..
> Can be important create more logical partitions in RAID system for improve
> defrag efficiency?
> Example: I have only one database in SQL. I create a system partition C, a
> database partition D and a log partition E.
> Can I have better performance putting database in D and log in E?
> Thank's a lot.. and sotty for my english..
> Andrea
>
>
|||I know that log files are writing sequentially to the disk btu with RAID 5 i
can decide to block the writing only on log disk...
but I can have no better performance to the defrag of log?
"fnguy" <fnguy@.discussions.microsoft.com> ha scritto nel messaggio
news:B17E4200-29D1-429B-AD10-B2A9C41DC43B@.microsoft.com...[vbcol=seagreen]
> Since the drives are all a single Raid 5 you will not gain any performance
> by
> spreading the data to the D drive and logs to the E drive.
>
> "Rusty73" wrote:
|||The best way to combat file fragmentation is to create the database files
once, as large as you will need them. If the files are allocated
contigueously, and never grow, then no file fragmentation will occur. Make
sure you give enough room for the Index Defrags, that will use internal data
pages, not file fragments to reorganize, again, as long as the file does not
grow.
Go ahead and leave the AUTOGROW feature on, but only as a fail-safe, in case
you've underestimated the space you will need.
Besides, file fragmentation will only affect scans and DSS type queries.
For a true OLTP system, the disk and database page access will be pretty
random, which will not be affected as much by file level fragmentation.
Sincerely,
Anthony Thomas

"Rusty73" <rusty77@.libero.it> wrote in message
news:%23iqlJn6tFHA.3932@.TK2MSFTNGP15.phx.gbl...
I know that log files are writing sequentially to the disk btu with RAID 5 i
can decide to block the writing only on log disk...
but I can have no better performance to the defrag of log?
"fnguy" <fnguy@.discussions.microsoft.com> ha scritto nel messaggio
news:B17E4200-29D1-429B-AD10-B2A9C41DC43B@.microsoft.com...[vbcol=seagreen]
> Since the drives are all a single Raid 5 you will not gain any performance
> by
> spreading the data to the D drive and logs to the E drive.
>
> "Rusty73" wrote:
|||Hi there,
Raid 5 will give you better performance for the DB.
For logs is best to create a mirror pair for improved performance, exactly
because of sequential writing.
My server is configured as follows:
system partition C - array of 2 mirrored drives - RAID 1
DB partition - array of a few disks in raid 5
log partition - another pair of mirrored drives - RAID 1
I agree with the previous comment that having different logical partitions
on the same disk array will not improve performance.
Hope this helps.
Kind regards,
Doru
"Anthony Thomas" <ALThomas@.kc.rr.com> wrote in message
news:u7bc6z$tFHA.2848@.TK2MSFTNGP10.phx.gbl...
> The best way to combat file fragmentation is to create the database files
> once, as large as you will need them. If the files are allocated
> contigueously, and never grow, then no file fragmentation will occur.
> Make
> sure you give enough room for the Index Defrags, that will use internal
> data
> pages, not file fragments to reorganize, again, as long as the file does
> not
> grow.
> Go ahead and leave the AUTOGROW feature on, but only as a fail-safe, in
> case
> you've underestimated the space you will need.
> Besides, file fragmentation will only affect scans and DSS type queries.
> For a true OLTP system, the disk and database page access will be pretty
> random, which will not be affected as much by file level fragmentation.
> Sincerely,
>
> Anthony Thomas
>
> --
> "Rusty73" <rusty77@.libero.it> wrote in message
> news:%23iqlJn6tFHA.3932@.TK2MSFTNGP15.phx.gbl...
> I know that log files are writing sequentially to the disk btu with RAID 5
> i
> can decide to block the writing only on log disk...
> but I can have no better performance to the defrag of log?
> "fnguy" <fnguy@.discussions.microsoft.com> ha scritto nel messaggio
> news:B17E4200-29D1-429B-AD10-B2A9C41DC43B@.microsoft.com...
>

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