Vmdk's or iscsi For SQL db and exchange db

[ful56_uk]

What best to use for SQL db and exchange db, vmdk's or iscsi targets?

 

Mark

[dhicks]

What best to use for SQL db and exchange db, vmdk's or iscsi targets?

 

A few years ago, when harddrives were a bit smaller, best practice used to be to simply assign your database an entire, raw harddrive (or RAID array) for it to use as it saw fit. The idea was that it would bypass any file system overhead and be able to write data directly to the harddrive, arranging disk reads and writes in the most efficient way. These days, an SQL database tends to be just a large file on an existing file system as most databases don't take up the disk space to fill an entire drive or RAID array. However, disk space these days is as cheap as it's ever been, so you'd probably still get best performance if you assign your database a whole block device - a harddrive, RAID array, or, in your case, probably a whole RAID array exported as an iSCISI target from your SAN.

[pantscat]

How busy is your SQL / Exchange box?

How fast is your SAN?

 

I've got my SQL and Exchange boxes running as normal vmdks... performance is just as good, if not better, than when they were physical boxes.

[qcomer]

We have just about everything virtualized now utilizing our iSCSI SAN for storage.

 

We use a seperate virtual disk for EACH of the following on our SQL servers: OS, databases, logs and backups.

For exchange we use a seperate virtual disk for EACH of the following: OS, Logs, Databases.

 

The virtual disks are created on several different LUNs which are RAIDed to specific RAIDs depending on their purpose.

[gshaw]

I think I'm going with vmdks when we do our virtual migration, splitting the data onto a separate vmdk from the OS drive (pretty much same as you would physically, just replace drives with virtual disks )

 

Will also make it easier to back up as Veeam can just lift the vmdks and whack them onto our backup target server.

Edited April 26, 2011 by gshaw