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  • 1.  SAN based snapshot

    Posted Aug 03, 2010 05:34 PM

    Is there any benefit to using a iSCSI SAN storage array system (i.e. HP MSA2000 series) to take snapshots of VM's over just using VMWare's snapshot feature?

    Thanks in advance for your comments.

  • 2.  RE: SAN based snapshot

    Posted Aug 03, 2010 05:43 PM

    Welcome to the Forums - Well it depends on what you are trying to do - both are meant for different things - SAN based snapshots are meant to be able to restore files/data while VMware based snapshots are meant for allowing a backup to made of the virtual disk or to return the VM to a point in time and two things to keep in mind:

    1. VMware snapshots are not meant to be continously running -

    2. SAN based Snapshots need to be integrated with VMware -

    If you find this or any other answer useful please consider awarding points by marking the answer correct or helpful

  • 3.  RE: SAN based snapshot

    Posted Aug 03, 2010 07:11 PM

    I'm interested in learning some common uses for the san snapshot in a vmware environment. What are some ways that san snapshots are used with vmware vm's? I'm imaginging a san based snapshot could be backed up to tape for disaster recovery. Is is possible to take a san snapshot of a running vm? Are there any other benefits I'm not aware of? I'm trying to decide whether to include licenses for san snapshots with the purchase of an iscsi san.

  • 4.  RE: SAN based snapshot

    Broadcom Employee
    Posted Aug 03, 2010 08:33 PM


    SAN snapshot is a great feature, but only for RDM disk's.

    from www.vmware.com/pdf/esx25_rawdevicemapping.pdf

    "--When SAN snapshot or other layered applications are run in the virtual machine. Raw

    device mapping better enables scalable backup offloading systems using the features

    inherent to the SAN.--"

    SAN snapshot is a storage technology, you cannot backup a san snapshot to tape.

  • 5.  RE: SAN based snapshot

    Posted Aug 05, 2010 09:09 PM

    I use both in my environment. I have daily/hourly replays 'snapshots' done on our SAN. I use this for disaster recovery purposes. I use VM snapshots when I am making changes to a guest so I have the ability to roll back if it goes sour. I do commit the changes made once I verify its correct. As said above, you dont want to continue running on snapshots for an extended period of time.

    Correction on the above post too, you can backup SAN snapshots. You just have to mount that LUN to another server, and then offload to another media (spinning disk / tape) like you would with any other backup. You could recover VMDK data that way by using VMware Workstation 5.5 Disk Mount Utility to mount the VMDK within Windows. Several ways to go about it, just depends what you are trying to do exactly.