7 Replies Latest reply on May 19, 2008 10:15 AM by sdonnet

    Backup ?

    sdonnet Enthusiast

       

      I need to reopen a thread already seen in Beta 1 forum, but, as I have always failed to backup my VMs, I need some VMWarer experiences... So :

       

       

      How can we "really" backup the VMs, without stopping or freezing them ?

       

       

      - I have tried simple "cp -R ... ", but this raises critical network errors into all VMs,

      - I have tried a snapshot of my LVM, and then "cp ...", but quite same problem,

      - I was unable to install (I spoke "when I was under Beta 1") the Vmware API, so I was not able to script something...

       

       

      Is there a good way to perform a backup ?

       

       

      (My conf : HP Proliant DualCore server, with host=CentOS 5 x64, VMWare Beta 2, and guests=CentOS 4 or Windows 2000 Server).

       

       

      TIA

       

       

        • 1. Re: Backup ?
          Paul Thomas Master

           

          I would not expect a copy of an open vmdk file to work, as it is in effect a disk which is being updated. I've used snapshot technology to take online/hot backups, but not of a windows OS. I'm not sure this would work, although you would expect the restored OS to behaive as if it had previously suffered a power failure.

           

           

          I've been giving some thoughts to backups and are currently considering the following options.

           

           

          Use a script to suspent the VM, then copy the files using cp then restart the VM. The downside of this is that the VM will be unaavailable, however it is simple and quick to restore.

           

           

          Use a product such as Norton Ghost to create an image.  You would also need to save the vmware config file *.vmx etc also.  This would allow the vms to run while being backed up, but a restore would involvbe more work.

           

           

          • 2. Re: Backup ?
            Peter_vm Guru

            There are some tools to perform backups in form of disk snapshots from within running guest OS.

            But I guess they will suffer the same problems as of the systems having their power interrupted.

            While most environments survive such event, some would suffer perceived data corruption (like large database servers).

            • 3. Re: Backup ?
              sdonnet Enthusiast

               

              Thanks Paul, thanks Peter,

               

               

              I am quite surprised that there is no "official" way, or "bulletprof" way to perform backups. From your points of view, what is the best or the less annoying way to do it :

              - script a freeze on each VM (how ?), and use something like Ghost for Linux to clone files, or rsync, or cp -R

              - script a freeze on each VM, and perform a LVM snapshot of VM files (I manually already tried to do it, but it failed, but it could be my fault),

              - wait for 2 years that VMware announce VMotion for VMserver 2

               

               

               

               

               

              • 4. Re: Backup ?
                sdonnet Enthusiast

                 

                I have performed new tests on backup. Strange behaviour of VMWare Beta 2 (already seen in Beta 1) :

                 

                 

                I have 8 VM on same server. I stop the 8th (completely stop it : Guest OS stopped, VM stopped). I backup this 8th by rsync... All is OK. Except that in all other running VM, and during my backup, I got some error messages :

                 

                 

                May  4 12:24:45 vm2 kernel: mptscsi: ioc0: attempting task abort! (sc=df91d040)

                May  4 12:24:45 vm2 kernel: scsi0 : destination target 0, lun 0

                May  4 12:24:45 vm2 kernel:         command = Write (10) 00 00 bf 31 ad 00 00 08 00

                 

                 

                 

                Do these messages are important ? Simple warnings ?

                 

                 

                • 5. Re: Backup ?
                  Paul Thomas Master

                   

                  I've seen similar problems when running several VM's and disk activity is high. One thing I have learned from evaluating VMWare, is that it does require a very performant disk system. 

                   

                   

                  I suspect the problem may be caused by paging, given the number of VM's you are running, I would expect a reasonable amount of paging to be going on.  If at the same time the disk(s) are being accessed heavily by a backup of a large file, the paging requests will take longer, and could then have a knock on effect with various timeout issues.

                   

                   

                  • 6. Re: Backup ?
                    Peter_vm Guru
                    sdonnet wrote:

                     

                    I am quite surprised that there is no "official" way, or "bulletprof" way to perform backups. From your points of view, what is the best or the less annoying way to do it :

                    What's a "bulletproof" way to perform a backup on physical system?

                     

                    - wait for 2 years that VMware announce VMotion for VMserver 2

                    It is almost like waiting for a free version of ESX...

                    • 7. Re: Backup ?
                      sdonnet Enthusiast

                       

                      sdonnet wrote:

                       

                      I am quite surprised that there is no "official" way, or "bulletprof" way to perform backups. From your points of view, what is the best or the less annoying way to do it :

                      What's a "bulletproof" way to perform a backup on physical system?

                      Any system "snapshoting" a file or a disk, ie performing a quite-coherent image of the disk.

                       

                      - wait for 2 years that VMware announce VMotion for VMserver 2

                      Peter_vm wrote:

                      It is almost like waiting for a free version of ESX...

                      I was,and still I am ready to pay for that. Why not a reasonable-not-free VMotion option?

                      Sorry Peter, I have'nt seen your remarks...