Thursday, September 25, 2008

Sizing your Exchange 2007 storage on a StorageTek 6140 & 6540 for 20.000 mailboxes

Over @ BigAdmin there are two good , articles on sizing your array's for those who have a 6140 or 6540

Choosing a block size when creating a vmfs datastore

When you create a VMFS datastore on your VMware ESX servers many administrators select the default 1MB block size without knowing when or why to change it. The block size determines the minimum amount of disk space that any file will take up on VMFS datastores. So an 18KB log file will actually take up 1MB of disk space (1 block) and a 1.3MB file will take up 2MB of disk space (2 blocks). But the block size also determines the maximum size that any file can be, if you select a 1MB block size on your data store the maximum file size is limited to 256GB. So when you create a VM you cannot assign it a single virtual disk greater then 256GB. There is also no way to change the block size after you set it without deleting the datastore and re-creating it, which will wipe out any data on the datastore.

Because of this you should choose your block size carefully when creating VMFS datastores. The VMFS datastores mainly contain larger virtual disk files so increasing the block size will not use all that much more disk space over the default 1MB size. You have the following choices when creating a datastore:

• 1MB block size – 256GB maximum file size
• 2MB block size – 512GB maximum file size
• 4MB block size – 1024GB maximum file size
• 8MB block size – 2048GB maximum file size

Besides having smaller files use slightly more disk space on your datastore there are no other downsides to using larger block sizes. There is no noticeable I/O performance difference by using a larger block size. When you create your datastore, make sure you choose your block size carefully. 1MB should be fine if you have a smaller datastore (less than 500GB) and never plan on using virtual disks greater then 256GB. If you have a medium (500GB – 1TB) datastore and there is a chance that you may need a VM with a larger disk then go with a 2MB or 4MB block size. For larger datastores (1TB – 2TB) go with a 4MB or 8MB block size. In most cases you will not be creating virtual disks equal to the maximum size of your datastore (2TB) so you will usually not need a 8MB block size.

So remember, choose carefully, once you create your datastore there is no changing it later.

Monday, September 08, 2008

Time to walk the dog

Thursday, September 04, 2008

When I grow up I wanna be

Wednesday, September 03, 2008

VMware ESX and ESXi Comparison

Here is the run down on the differences between ESX and ESXi.

OpenSolaris intergration with Active Directory

Came across this on how to get your opensolaris box talking to Active Directory. You can check out the link here

Tuesday, September 02, 2008

Solaris 10 with ZFS as NFS target for VMware ESX

Thomas Weyell over @ Sun has an awesome set by setup on creating a ZFS pool and sharing it via NFS for your ESX Host.

You can read the full article here

Monday, September 01, 2008

Apple Visio Stencils

So for those of you looking to add some Apple kit into your visio diagrams I found a site which has some (very pretty indeed) You can download them here