maximum size of datastore in ESXi 4

[coolgod]

as i dont have much space left on my vmfs3 datastore, am planning to add a 3 TB Hard Disk to the ESXi 4.1 Host. I will then use the new hard disk for a creating a new datastore.

I also want to make sure the block size is same as the existing datastore.

please advise.

Thanks.

[schepp]

Hi,

the max VMFS3 size with ESXi 4.X is 2TB per LUN. If you want to to be bigger than 2TB, you would need to extend it over multiple LUNs.

In ESXi 5.X you can create VMFS3 volumes up to 50TB

For more information look at the "Additional Information" section of this kb article: http://kb.vmware.com/kb/1003565

Regards

Tim

[coolgod]

thanks tim for the link.

please note that I don't have a SAN and as I far i know LUN is about using SAN.correct me if am wrong here.

the only method i have is to buy new hard disks and put in the ESXi host.

please advise.

[schepp]

It's the same for local storage.

When you present a 3TB disk to ESXi 4.X, it will most likely only show the part that is over 2TB, So with a 3TB disk, which has a usable capacity of 2,7 TiB, your host will only see ~728GB.

To prevent this you have to create smaller volumes in your local raid controller

[coolgod]

thanks for clarifying this.

please also advise how do i make sure that when i add the second datastore it has the same block size as the existing one.

i read on the VMWARE KB that if you are moving a VM from a datastore with block size x to another datastore with block size y , mismatched

block size might create trouble.

[a_p_]

You can define the block size when you create the datastore (Add Storage ...). The block size defines the maximum possible file size (e.g. the size of a virtual disk) on the datastore, see tables in http://kb.vmware.com/kb/1012384.

When you migrate a VM between datastores with different block sizes, migration is slower than migrating between datastores with the same block size (see e.g. Blocksize impact? - Yellow Bricks). However, - disregarding the speed - the important part is to ensure that the target datastore's block size meets the requirements for the VM's virtual disk sizes.

André

[coolgod]

i checked the block size on the ESXi .. its 4 MB.

So just please confirm me that the maximum physical hard disk i can add is 2 TB.

[a_p_ · Accepted solution]

The maximum LUN/disk size in this case is 2TB minus 512 Bytes (see VMware KB: ESX/ESXi 3.x/4.x hosts do not support 2-terabyte LUNs for details). For the maximum virtual disk size with a 4MB block size, please take a look at the KB article I mentioned in my previous post.

André

[coolgod]

thanks a.p for clarifying this.