Performance with dynamic disk, various clustering

[Trapulo]

I'm going to install a SBS 2000 with exchange and SQL Server.

My server has a raid controller with 2 containers configured. The one is
20GB large, the second 110GB.
On the first I've set a single primary partition with NTFS, formatted 4-kb
clusters, with the system and the software.

On the second I'll put SQL Server data, Exchange data, and other data (web
sites). I think I'll convert the disk to dynamic, and I'll make two volumes.
The one formatted ntfs 64Kb-clustered, the second ntfs 4Kb-clustered. On the
one I'll put the sql server data, on the second the rest.
Then I'll leave unused disk space (about 40Gb) to use if one of the two data
partition will go out of space (I'm not sure the exact data load for sql
server and for exchange). So I'll can expand the partitions with the free
space, because they are on a dynamic disk

Is this a good idea?
I've some performance problem with the dynamic disk? Even if I expand the
volumes with non contiguos space?
The performance gain for sql server, using 64-kb cluster volumes, is
important?
Now I've the page file on the system partition (4kb cluster). Can be betterm
move it on a 64kb-cluster volume?

thanks

 

[Shane Ferrell [MS]]

From an overall system standpoint I would say that you would be better off
to keep the 2 partitions and format them with the default cluster size
(4kb?).



SQL has semi-static database size (i.e. you create your X database at 20 GB
or whatever, and then grow it when you need).



Exchange databases are dynamically growing. I.e. it starts at 2MB and grows
till it reaches steady state (mail quota x # users + some factor)



The difference between cluster size and dynamic vs. basic disk are small
(couple of percent), while differences on how the drives are configured
(Raid 5 vs. 0+1) are large (100% diff on writes), or in the physical
partition scheme - i.e. separate log disks from database (2-500%).



I would put all available disk space online, and then if you need it, it
will be there.



If you have extra spindles, I would look at dedicating disk to exchange logs
or SQL logs.



Let me know if you have any more questions.

Shane Ferrell

Exchange Deployment Tester



DISCLAIMER:

This posting is provided "AS IS" with no warranties, and confers no rights

 

[Trapulo]

From an overall system standpoint I would say that you would be better off
to keep the 2 partitions and format them with the default cluster size
(4kb?).

I think is 4Kb.
But I know that for SQL Server is better to have 64kb cluster size, because
(I think) it uses big files.

SQL has semi-static database size (i.e. you create your X database at 20 GB
or whatever, and then grow it when you need).

does this affect cluster size selection?

Exchange databases are dynamically growing. I.e. it starts at 2MB and grows
till it reaches steady state (mail quota x # users + some factor)

The difference between cluster size and dynamic vs. basic disk are small
(couple of percent), while differences on how the drives are configured
(Raid 5 vs. 0+1) are large (100% diff on writes), or in the physical
partition scheme - i.e. separate log disks from database (2-500%).

I know. I've RAID 1+0 for this reason. However I cannot have other disks for
logs.

I would put all available disk space online, and then if you need it, it
will be there.

Do you mean a single basic partition 4.kb clustered?


thanks

 

[Shane Ferrell [MS]]

INLINE

I think is 4Kb.
But I know that for SQL Server is better to have 64kb cluster size, because
(I think) it uses big files.


does this affect cluster size selection?

Not really. I would go for the default 4KB cluster.

I know. I've RAID 1+0 for this reason. However I cannot have other disks for

Do you mean a single basic partition 4.kb clustered?

I would go a single partion for the system drive (OS, Page, programs)
then a second Partition for the Data. If you wanted you could devide the
data between the SQL and the Exchange, but I would do this from a management
stand point rather than a performance stand point. i.e. if you know that the
SQL database is going to need 30 GB then create a 40GB partition of SQL and
the rest for Exchange. If you are not sure how big either of them are going
to get then, use 1 big volume (110 GB) and you can make it basic (can
upgrade to dynamic later if you need to add disk space).

 

[Carl Appellof]

SQL has semi-static database size (i.e. you create your X database at 20 GB
or whatever, and then grow it when you need).

MS SQL can be set to autogrow its database files too, but it's probably best
to preallocate a big chunk.

Carl Appellof