We are currently running vmware esx server in our office network. Our vmware guest machines are running Ubuntu Server 11.04.
What we’re looking for is a way to share a storage space accessible by guest machines by using a virtual disk. If one of the guest machines writes to the shared storage space, then all other guests would see the change.
I have read a post about creating a vmdk that get’s mounted on the guest. But the post also mentions that none of the guests would see changes if one of the guests writes unless the disk is remounted. Is this correct?
Does anyone know how set this up strictly via vmware ? (meaning not using a nas guest machine configured with cifs, smb, nfs, etc.. for sharing)
You are asking for a “multi-writer” shared disk. VMware supports this (its used to support MSCS clusters, and VMware fault tolerant VMs), but there are not a lot of filesystems or OSes that can take advantage of this — I’m pretty confident none of the standard Ubuntu filesystems are capable of this. This setup is the virtual equivalent of plugging a single SCSI drive into two separate hosts … the caching and consistency issues are not trivial for the hosts to use the shared storage without clobbering each other.
Here is a VMware KB article about enabling multi-writer mode:
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1034165
There are also implications for VM management (migration, backups, etc) that get much more complicated with shared disks to be aware of.