I was wondering if you can share a datastore across multiple clusters without any locking issues. Single Datacenter, but multiple Clusters(Esxi 4 and 5). Luns to be shared across Clusters are VMFS3.
Some pros and cons can be found in these articles...
http://www.yellow-bricks.com/2010/02/05/storage-masking/
Concerns would be an APD condition impacting more than 1 cluster, as well the ability for said LUN to perform when accessed from multiple hosts from multiple clusters.
The original use case as a swing-LUN for migrating VMs between clusters but which is no longer necessary in vSphere 5.1 with enhanced vMotion functionality.
HTH
Cormac
Yes this is possible. You can even vMotion VMs between clusters, provided the hosts are compatible.
André
I thought so. I had our SAN vendor say they would be corruption---basically had the mirror the cluster format on our SANs and when mapping luns between them it errored. I explained that esx would take care of the locking issues. Just thought I would check. Thanks,,,
Locking concerns are usually more around the quantity of VMs running on a datastore and if VAAI is supported, not how many clusters / hosts are presented. Your vendor may be thinking more around something like Windows failover clustering, which only allows one node to actively use the disk at once.
Note: Without VAAI, the entire LUN is locked when a write needs to occur. With VAAI, the ATS primitive allows you to do sub-LUN locks for just that VM.
Yes we have 1 SAN that suppors ATS,,the other will after a firmware upgrade. Excited to start using it. Will make a big difference, though we dont see a lot of reservation problems. thanks!
Some pros and cons can be found in these articles...
http://www.yellow-bricks.com/2010/02/05/storage-masking/
Concerns would be an APD condition impacting more than 1 cluster, as well the ability for said LUN to perform when accessed from multiple hosts from multiple clusters.
The original use case as a swing-LUN for migrating VMs between clusters but which is no longer necessary in vSphere 5.1 with enhanced vMotion functionality.
HTH
Cormac
Thanks, I forgot about that. I assume on non-shared storage the data is simply moved through the vmotion network?
Also these clusters are 4.1 and 5.1,,,so i dont think this will work entirely for me. therefore i may have to use a swing lun.
A
Yes - its only available in 5.1.
There is a great deep-dive on it here - http://frankdenneman.nl/vmotion/vsphere-5-1-vmotion-deepdive/
Yes - a datastore can be shared at the storage level across multiple clusters - this is not dependant on 5.1, we have been able to do this forever.
Thanks everyone!