Hardware Logical Drives or OS Level Partitions?

Is it better to divide an array into multiple partitions (or volumes) at the
OS level or into multiple logical drives at the hardware level? Does it make
any difference to track alignment? Will one give greater future flexibility
over the other?
I have to install SQL Server on an HP Proliant server with 6 drives bays - I
would prefer more, but that is what I have available. I plan to create 3
RAID 1 arrays using the HP Array Configuration Manager to use as follows:
Array 1 (disks 0 & 1)
C:\ OS
S:\ SQL Server Installation
T:\ TempDB
Array 2 (disks 2 & 3)
P:\ Page File
D:\ Data
Array 3 (disks 4 & 5)
L:\ Transaction Logs
X:\ Backups
All partitions will be formatted with NTFS. I plan a stripe and cluster
size of 64KB for the data and TempDB partitions - all the others will be
default sizes. DB backups will be made to a local drive and then backed up
to tape over the network.
This configuration gives good separation for resillience. It should reduce
file fragmentation and I hope will give reasonable performance.
Thanks for any comments
Why not use disks 2-5 as RAID0+1 and move tempdb to it. You can still create
partitions to split stff up if you want.
Jason Massie
www: http://statisticsio.com
rss: http://feeds.feedburner.com/statisticsio
"andrew" <andrew@.discussions.microsoft.com> wrote in message
news:9498413C-FE6F-4DCA-B042-00B84890086B@.microsoft.com...
> Is it better to divide an array into multiple partitions (or volumes) at
> the
> OS level or into multiple logical drives at the hardware level? Does it
> make
> any difference to track alignment? Will one give greater future
> flexibility
> over the other?
> I have to install SQL Server on an HP Proliant server with 6 drives bays -
> I
> would prefer more, but that is what I have available. I plan to create 3
> RAID 1 arrays using the HP Array Configuration Manager to use as follows:
> Array 1 (disks 0 & 1)
> C:\ OS
> S:\ SQL Server Installation
> T:\ TempDB
> Array 2 (disks 2 & 3)
> P:\ Page File
> D:\ Data
> Array 3 (disks 4 & 5)
> L:\ Transaction Logs
> X:\ Backups
> All partitions will be formatted with NTFS. I plan a stripe and cluster
> size of 64KB for the data and TempDB partitions - all the others will be
> default sizes. DB backups will be made to a local drive and then backed
> up
> to tape over the network.
> This configuration gives good separation for resillience. It should
> reduce
> file fragmentation and I hope will give reasonable performance.
> Thanks for any comments
|||Partitioning at the OS level does nothing to enhance or degrade performance.
The underlying RAID container has exactly the same IO capacity no matter how
you partition it. RAID containers can and do segment IO loads and can have
significant impact on performance.
Geoff N. Hiten
Senior SQL Infrastructure Consultant
Microsoft SQL Server MVP
"andrew" <andrew@.discussions.microsoft.com> wrote in message
news:9498413C-FE6F-4DCA-B042-00B84890086B@.microsoft.com...
> Is it better to divide an array into multiple partitions (or volumes) at
> the
> OS level or into multiple logical drives at the hardware level? Does it
> make
> any difference to track alignment? Will one give greater future
> flexibility
> over the other?
> I have to install SQL Server on an HP Proliant server with 6 drives bays -
> I
> would prefer more, but that is what I have available. I plan to create 3
> RAID 1 arrays using the HP Array Configuration Manager to use as follows:
> Array 1 (disks 0 & 1)
> C:\ OS
> S:\ SQL Server Installation
> T:\ TempDB
> Array 2 (disks 2 & 3)
> P:\ Page File
> D:\ Data
> Array 3 (disks 4 & 5)
> L:\ Transaction Logs
> X:\ Backups
> All partitions will be formatted with NTFS. I plan a stripe and cluster
> size of 64KB for the data and TempDB partitions - all the others will be
> default sizes. DB backups will be made to a local drive and then backed
> up
> to tape over the network.
> This configuration gives good separation for resillience. It should
> reduce
> file fragmentation and I hope will give reasonable performance.
> Thanks for any comments
|||thanks Geoff
by RAID container I take it you mean a logical drive created at hearware
level with the array.
"Geoff N. Hiten" wrote:

> Partitioning at the OS level does nothing to enhance or degrade performance.
> The underlying RAID container has exactly the same IO capacity no matter how
> you partition it. RAID containers can and do segment IO loads and can have
> significant impact on performance.
> --
> Geoff N. Hiten
> Senior SQL Infrastructure Consultant
> Microsoft SQL Server MVP
>
>
> "andrew" <andrew@.discussions.microsoft.com> wrote in message
> news:9498413C-FE6F-4DCA-B042-00B84890086B@.microsoft.com...
>
|||Thanks Jason
I did consider this, but thought I would be better with the separation. Do
you think 1 RAID 10 array would perform better than 2 RAID 1?
"jason" wrote:

> Why not use disks 2-5 as RAID0+1 and move tempdb to it. You can still create
> partitions to split stff up if you want.
>
> --
> Jason Massie
> www: http://statisticsio.com
> rss: http://feeds.feedburner.com/statisticsio
>
> "andrew" <andrew@.discussions.microsoft.com> wrote in message
> news:9498413C-FE6F-4DCA-B042-00B84890086B@.microsoft.com...
>
|||Correct.
Geoff N. Hiten
Senior SQL Infrastructure Consultant
Microsoft SQL Server MVP
"andrew" <andrew@.discussions.microsoft.com> wrote in message
news:D1EA04BC-EA2F-4F42-85B5-4057C9231E5C@.microsoft.com...[vbcol=seagreen]
> thanks Geoff
> by RAID container I take it you mean a logical drive created at hearware
> level with the array.
> "Geoff N. Hiten" wrote:
|||You said "DB backups will be made to a local drive and then backed up to
tape over the network."
I don't know what way you'll use to copy your backups thru your network
however I just wanted to stress that "BACKUP ... to TAPE" can not be used to
backup a database to a tape which is attached to a remote machine even if it
would be in the same network. The backup tape must be connected directly to
the SQL Server server to backup a database to tape.
Also, storing the OS and SQL Server binaries on the same drive would be OK
If tempdb is used in your environment frequently then you may consider
putting it on a dedicated disk which could be (if you don't need redundancy
or if you don't have enough resource for RAID1) RAID0.
However as Geoff mentioned, it would not make any difference to separate a
disk logically. You need physical disks to gain performance benefit for this
purpose.
You will want to give enough physical file space to your Transaction Log
file and Data files if you want less fragmentation.
Ekrem ?nsoy
"andrew" <andrew@.discussions.microsoft.com> wrote in message
news:9498413C-FE6F-4DCA-B042-00B84890086B@.microsoft.com...
> Is it better to divide an array into multiple partitions (or volumes) at
> the
> OS level or into multiple logical drives at the hardware level? Does it
> make
> any difference to track alignment? Will one give greater future
> flexibility
> over the other?
> I have to install SQL Server on an HP Proliant server with 6 drives bays -
> I
> would prefer more, but that is what I have available. I plan to create 3
> RAID 1 arrays using the HP Array Configuration Manager to use as follows:
> Array 1 (disks 0 & 1)
> C:\ OS
> S:\ SQL Server Installation
> T:\ TempDB
> Array 2 (disks 2 & 3)
> P:\ Page File
> D:\ Data
> Array 3 (disks 4 & 5)
> L:\ Transaction Logs
> X:\ Backups
> All partitions will be formatted with NTFS. I plan a stripe and cluster
> size of 64KB for the data and TempDB partitions - all the others will be
> default sizes. DB backups will be made to a local drive and then backed
> up
> to tape over the network.
> This configuration gives good separation for resillience. It should
> reduce
> file fragmentation and I hope will give reasonable performance.
> Thanks for any comments
|||Thanks Ekrem
Our backup plan is to run SQL backups to disk, then backup these files using
an enterprise backup solution along with system state etc. This eliminates
some of the additional complexities of backing up across the network (the
backup is less likely to fail if there are network problems or the other
server isn't available) and also means we have a local backup if we need it
for a partial restore or corrupt database.
I would love to put TempDB on a separate disk, but that is not possible in
this server as it only has 6 drive bays. I think separating logs and data
probably has a higher priority. I would hesitate to put TempDB on RAID 0 as
it still needs to be present, even if there is no data to preserve, or SQL
Server will fail.
We desperately need to replace some very old hardware right now and we
already have this server. Buying replacement hardware is a project for the
future - that box will have more drives!
"Ekrem ?nsoy" wrote:

> You said "DB backups will be made to a local drive and then backed up to
> tape over the network."
> I don't know what way you'll use to copy your backups thru your network
> however I just wanted to stress that "BACKUP ... to TAPE" can not be used to
> backup a database to a tape which is attached to a remote machine even if it
> would be in the same network. The backup tape must be connected directly to
> the SQL Server server to backup a database to tape.
> Also, storing the OS and SQL Server binaries on the same drive would be OK
> If tempdb is used in your environment frequently then you may consider
> putting it on a dedicated disk which could be (if you don't need redundancy
> or if you don't have enough resource for RAID1) RAID0.
> However as Geoff mentioned, it would not make any difference to separate a
> disk logically. You need physical disks to gain performance benefit for this
> purpose.
> You will want to give enough physical file space to your Transaction Log
> file and Data files if you want less fragmentation.
> --
> Ekrem ?nsoy
>
> "andrew" <andrew@.discussions.microsoft.com> wrote in message
> news:9498413C-FE6F-4DCA-B042-00B84890086B@.microsoft.com...
>
|||Data and Log files have more priority for sure.
Ekrem ?nsoy
"andrew" <andrew@.discussions.microsoft.com> wrote in message
news:13CD654F-8041-424B-903F-60389E725823@.microsoft.com...[vbcol=seagreen]
> Thanks Ekrem
> Our backup plan is to run SQL backups to disk, then backup these files
> using
> an enterprise backup solution along with system state etc. This
> eliminates
> some of the additional complexities of backing up across the network (the
> backup is less likely to fail if there are network problems or the other
> server isn't available) and also means we have a local backup if we need
> it
> for a partial restore or corrupt database.
> I would love to put TempDB on a separate disk, but that is not possible in
> this server as it only has 6 drive bays. I think separating logs and data
> probably has a higher priority. I would hesitate to put TempDB on RAID 0
> as
> it still needs to be present, even if there is no data to preserve, or SQL
> Server will fail.
> We desperately need to replace some very old hardware right now and we
> already have this server. Buying replacement hardware is a project for
> the
> future - that box will have more drives!
>
> "Ekrem ?nsoy" wrote:
|||Yes especially with the limited amount of drives. You are separating the
data and logs but you are also dividing the max throughput. BTW, in a small
hp config like this, I would set the stripe size in the ACU at 64k and the
cache to 0% read and 100% write(providing you have enough RAM). Sector align
with diskpart using a 128k offset as well.
Jason Massie
www: http://statisticsio.com
rss: http://feeds.feedburner.com/statisticsio
"andrew" <andrew@.discussions.microsoft.com> wrote in message
news:2BD76934-6814-46D7-BA51-EDBF09438BF0@.microsoft.com...[vbcol=seagreen]
> Thanks Jason
> I did consider this, but thought I would be better with the separation.
> Do
> you think 1 RAID 10 array would perform better than 2 RAID 1?
> "jason" wrote: