Unable to remove iSCSI Datastore

[crescendas]

We have a 1TG iSCSI Datastore mapped into ESX 4.0 that is configured as 1MB block size. After expanding this to 2TG and realizing that 1MB block size can only support up to 1TG, we are no longer able to remove this Datastore. Error message:

Remove datastore
192.168.190.199
Error during the configuration of the host:
DestroyVmfsDatastore: can't delete partition 1 on lun
naa.6090a068c0a6e5bc8fcd14481201102c

What can we do about this?

[idle-jam]

there could be some VMDKs and etc still in that datastore. you will need to delete it and unregister VM and then you are good to delete the datastore without any dependancy. have a look at this thread particularly the end of the discussion on detailed instructions: http://communities.vmware.com/thread/147591

[chriswahl]

Actually, a 1MB block size can only support a 256GB vm disk.

http://kb.vmware.com/kb/1003565

I'd recommend going with an 8MB block size. There's no substantial downside to choosing this size and it allows you to completely fill a 2TB-512byte LUN if needed and reduces the amount of grows needed on a thin disk. Some supporting details here:

http://www.yellow-bricks.com/2009/05/14/block-sizes-and-growing-your-vmfs/

[crescendas]

Hi idle-jam,

My 2TG database is completely empty. The thread suggestion of logging into the ESX host directly instead of vCenter to delete the datastore does not work for me. The same error appear:

Remove datastore
192.168.190.199
Error during the configuration of the host:
DestroyVmfsDatastore: can't delete partition 1 on lun
naa.6090a068c0a6e5bc8fcd14481201102c

What will happen if I bring this datastore offline from my SAN storage? My main concern is, will it affect my other iSCSI datastores?

[crescendas]

Sorry, you are right. The problem isn't with the 256GB, but with the 2TG-512kb limits. Since we have expanded this datastore to 2TB that cause vCenter to go crazy, is there a way to remove this datastore now?

[crescendas]

Found a resolution from vmware but no sure how safe it is to proceed:

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=101710...

[AndreTheGiant]

If datastore is empty you can mask the LUN from the storage side and make a rescan for all hosts.

If you see the the LUN is no more visible, then you can remove the LUN from storage side.

Andre