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    Backup Alternatives

    Scheduled Pinned Locked Moved Backup
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    • R Offline
      rfx77
      last edited by

      The problem we have with XOA Backup is that it does not support Deduplication like Kopia, Borg or Restic. So we have to do our VM Backups with a script.

      The problem we faced with a simple solution like dump xva or ova files to kopia/restic/borg is that the tar file-format and the metadata (directory name Ref...) is different on every export (even when you export the same snapshot twice) and because of that dedup does not work (well). we had to do separate export for metadata and VDIs but because of this a restore is not unattended.

      I looked a little bit into the implementation of the XOA OVA export code and in my opinion, it should be possible for Vates to alter the format so that is could be deduplicated well. you than can easily stream it via stdin to kopia. kopia can also dump to stdout so restore should also be possible.

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      • olivierlambertO Offline
        olivierlambert Vates 🪐 Co-Founder CEO
        last edited by

        Is deduplication such a big deal? I mean, the cost of it is not negligible and (at least with SMAPIv1) the gain isn't great at all.

        R 1 Reply Last reply Reply Quote 0
        • R Offline
          rfx77 @olivierlambert
          last edited by rfx77

          @olivierlambert

          With dedup i mean dedup of the backup repo. And its an extremely big deal for backup repos. Backup vendors put a lot of effort in this. CommVault and NetBackup have it natively and Veeam does recommend deduplicated storage (Data Domain,...).

          In our case we use an S3 backend and if you pay for a month worth of full backups 2-3 times a full backup size or 30 times a compressed full backup size is really a big deal. And we keep out backups sometimes for month.

          We are doing bi-weekly fulls with our homebuilt kopia strategy of a 1.3 TB SR (no empty disks) and are using apx. 1.37 TB S3.

          e1559b4e-5935-44f9-a47a-b9be9fcaddcb-image.png

          its from 0.64 TB up to 1.37 TB. Green is size used and black are the blocks which could be deleted.

          if someone is interested why we use kopia instead of restic. restic is super slow on dumps to stdout and on mount. we use mount in combination with libguestfs to do file-level-recovery.

          this is the script. not super professional and not the best error-handling but it may be useful:

          #!/bin/bash
          
          
          
          VMNAME=$1
          SERVER=$2
          SERVER=${SERVER:=172.25.10.2}
          
          BACKUPDESC="Backup $(date +'%Y-%m-%d %H:%M:%S') of VM $VMNAME"
          
          echo "$(date +'%Y-%m-%d %H:%M:%S') Starting Backup of vm $VMNAME"
          
          
          echo SERVER:$SERVER
          
          
          PASS=$(cat /root/.pass)
          export XE_EXTRA_ARGS="server=$SERVER,port=443,username=root,password=$PASS"
          
          
          
          VMID=$(xe  vm-list name-label=$VMNAME | grep uuid | sed "s/.*: //g")
          
          if [ -z "$VMID" ]
          then
            echo VMID not found
            exit 1
          fi
          
          echo VMID: $VMID
          
          SNAPID=$(xe vm-snapshot uuid=$VMID  new-name-label=backup_$VMNAME)
          
          if [ -z "$SNAPID" ]
          then
            echo SNAPID not found
            exit 1
          fi
          
          
          echo SNAPID: $SNAPID
          
          declare -a DISKID
          declare -a DISKNAME
          
          
          TEMPD=$(mktemp -d)
          mkdir $TEMPD/data
          
          echo "$(date +'%Y-%m-%d %H:%M:%S') Temp directory: $TEMPD"
          xe vm-export metadata=true uuid=$VMID filename=$TEMPD/data/metadata.ova.tar
          xe snapshot-disk-list uuid=$SNAPID vdi-params=all vbd-params=all > $TEMPD/data/vdi.txt
          xe vm-list name-label=$VMNAME params=all > $TEMPD/data/vm.txt
          
          ls -l $TEMPD/data
          
          
          
          DISKID=( $(xe snapshot-disk-list uuid=$SNAPID vdi-params=uuid,name-label vbd-params=false | grep uuid | awk '{print $5}') )
          DISKNAME=( $(xe snapshot-disk-list uuid=$SNAPID vdi-params=uuid,name-label vbd-params=false | grep name-label |  awk '{print $4}') )
          echo DISKID: ${DISKID[@]}
          echo DISKNAME: ${DISKNAME[@]}
          
          for i in ${!DISKID[@]}; do
            DN=${DISKNAME[$i]}
            DID=${DISKID[$i]}
            echo "$(date +'%Y-%m-%d %H:%M:%S') tagging disk $i is ${DID} ${DN}"
            xe vdi-param-set name-description="$BACKUPDESC" uuid=$DID
          done
          
          
          
          for i in ${!DISKID[@]}; do
            DN=${DISKNAME[$i]}
            DID=${DISKID[$i]}
            echo "$(date +'%Y-%m-%d %H:%M:%S') backup disk $i is ${DID} ${DN}"
          
            xe vdi-export uuid=$DID filename= format=raw | kopia snapshot create --tags=vm:$VMNAME,data=$DN --no-progress --log-level=warning --override-source=/vms/$VMNAME/$DN --stdin-file=${DID}.vhd - || echo "ERROR"
            sleep 5
            xe vdi-destroy uuid=$DID
          done
          
          
          
          tar cvpf $TEMPD/metadata.tar -C $TEMPD/data .
          kopia snapshot create  --tags=vm:$VMNAME,data=meta  --no-progress --log-level=info --override-source=/vms/$VMNAME $TEMPD/metadata.tar || echo "ERROR"
          rm -rf $TEMPD
          echo "$(date +'%Y-%m-%d %H:%M:%S') waiting 30s"
          sleep 30
          
          echo "$(date +'%Y-%m-%d %H:%M:%S') deleting snapshot $SNAPID of VM $VMNAME"
          xe snapshot-uninstall uuid=$SNAPID force=true || echo ERROR
          sleep 20
          xe snapshot-uninstall uuid=$SNAPID force=true > /dev/null 2>&1 || true
          
          
          
          echo "$(date +'%Y-%m-%d %H:%M:%S') Done Backup of vm $VMNAME"
          
          
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          • olivierlambertO Offline
            olivierlambert Vates 🪐 Co-Founder CEO
            last edited by olivierlambert

            We tried dedup for the backup repo with ZFS, to see the ratio kept. Due to VHD fragmentation, the gain was between 10 to 30% tops. Far far from being useful. That's why I think it would makes sense with SMAPIv3 and not v1 (because of the VHD format and its fragmentation)

            edit: also a simple script like this won't be able to deal with chain protection and many other important features.

            R 1 Reply Last reply Reply Quote 0
            • R Offline
              rfx77 @olivierlambert
              last edited by

              @olivierlambert The problem is what you dedup.

              We dedup raw VDI exports and they are nearly perfect dedup candidates.
              I attached our script in the previous post.

              With XVA i also only get 25% dedup ratio because of the tar metadata-problem. We decided that this is useless.

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              • olivierlambertO Offline
                olivierlambert Vates 🪐 Co-Founder CEO
                last edited by

                We tested to dedup the VHD exported. Your dedup ratio will diminish inexorably with time, as your VHD will become more and more fragmented. In raw, it should be similar at some point, since blocks aren't removed after usage (no trim support in SMAPIv1)

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                • R Offline
                  rfx77
                  last edited by

                  To clarify: In a XVA the folder names are of the kind Ref... and the number in the folder-name is random. This kills the dedup. If we could force the folder-name to be like Disk_[1,2,3,4] XVAs would be very good deduplicatable

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                  • R Offline
                    rfx77 @olivierlambert
                    last edited by rfx77

                    @olivierlambert
                    We are using dedup backup-stores for years now and yes they grow if you keep very long time-ranges. but they never grow as much as compressed fulls. and if you only keep shorter ranges (1-2 month) than the dedup ration will be nearly constant after some month.

                    I just checked the CommVault-Repos of our customers and they are all above 70% dedup saving and about 50% of the repos are above 90% dedup saving.

                    Depending on the size of their backup NAS they all have retention seetings between 60 days and one year.

                    Our own XenBackup S3 repo for Kopia will stop to grow when we delete older snapshots. for now we just kep backing up and this is the reason why it grows.

                    73bfd47b-7573-41cf-be52-a802d77d8f1c-image.png

                    i removed the first column because it would show confidential customer information.

                    olivierlambertO R 2 Replies Last reply Reply Quote 0
                    • nikadeN Online
                      nikade Top contributor
                      last edited by

                      Dedup is a huge deal, in our SAN we're seeing a 6.7:1 ratio which means we're saving a ton of money. With that said, Veeam for example also has dedup but it totally sucks.
                      I think it might be hard to get a good ratio with backup-data.

                      R 1 Reply Last reply Reply Quote 0
                      • olivierlambertO Offline
                        olivierlambert Vates 🪐 Co-Founder CEO @rfx77
                        last edited by olivierlambert

                        @rfx77 I don't know how you can keep shorter range if you do forever incremental 🤔 The fragmentation will only grow

                        K R 2 Replies Last reply Reply Quote 0
                        • K Offline
                          KPS Top contributor @olivierlambert
                          last edited by

                          Is there any possibility to disable compression?
                          I think, it could be a good option to fully give ZFS control over the remote:

                          • ZFS can do compression
                          • Without "external compression", deduplication could be much more efficient
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                          • olivierlambertO Offline
                            olivierlambert Vates 🪐 Co-Founder CEO
                            last edited by

                            We benched ZFS dedup without compression and the result was bad. I'm convinced everything will change with a proper data path that will support trim.

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                            • R Offline
                              rfx77 @olivierlambert
                              last edited by

                              @olivierlambert dedup has nothing to do with forever incremental.

                              if you are doing backups, only the changed blocks are stored and the blocks which are not used in any backup are deleted. all blocks are backuped but the software stores only the blocks which are new

                              with our kopia solution we do always full backups. kopia manages the dedup. with commvault we do fulls and incs

                              i think that most people here are thinking to much backup as the way veeam does it with reverse-inc and forever inc. veeam does it in a very specific way. with commvault, netbackup,... we do classic fulls and incs.

                              i dont know how to describe it better. if you do an incremental backup you only backup the changed blocks. when you do a full afterwards these blocks are already in the backup repo so they dont have to be written. you can do incs and fulls and you will only have the blocks in the repo which are necessary to restore these backups. so one year of daily fulls or incs may not use more then 3-4 times a full in the backup repo.

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                              • R Offline
                                rfx77 @rfx77
                                last edited by

                                To be clear. i never talked about deduplicated storage. i am always talking about deduplicated backup store. the edup is not done by the fs but by the backup-software

                                deduplicated storage is a completely different topic which can be addresse with sapiv3 but its not the think my posts are all about

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                                • R Offline
                                  rfx77 @olivierlambert
                                  last edited by rfx77

                                  @olivierlambert we are talking about different things. i dont mean dedup storage. i am talking about deduplicated backup store. the dedup is done by the backup-software (kopia,restic,borg, commvault,...) they support various backends like s3, ftp, sftp, local disk,...

                                  olivierlambertO 1 Reply Last reply Reply Quote 0
                                  • R Offline
                                    rfx77 @nikade
                                    last edited by

                                    @nikade You can see the ratios in the picture above. they are all around 90%

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                                    • olivierlambertO Offline
                                      olivierlambert Vates 🪐 Co-Founder CEO @rfx77
                                      last edited by olivierlambert

                                      @rfx77 That's exactly what I'm talking about. As I said, we tested dedup ratio with exported VHD files and it tends to diminish pretty quickly as you have more and more fragmentation, at a point it's worthless. But, yes it works pretty well if you have similar templates underneath and little fragmentation.

                                      W R 2 Replies Last reply Reply Quote 0
                                      • W Offline
                                        wtdrisco @olivierlambert
                                        last edited by wtdrisco

                                        @olivierlambert this backup looks really good. I currently in my VMware space use veeam. It's ok. I mainly just run backups of my virtuals and move them to an offline storage so if an encryption hack gets in, they can't encrypt the disks. So I run a script to move the file through a link to a Synology. That is just the VMs. For all my SQLs I run smss jobs to back up dbs and then transaction logs every 15 min. Again moving to offline storage. That gets me at least 15 min recovery to the crash. So I really do not focus too much on the backup software but to get me a VM back but my data i do separately so I have to ability to restore locally or move it to external resource. People here have some good discussions on the backup. Good thread

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                                        • R Offline
                                          rfx77 @olivierlambert
                                          last edited by rfx77

                                          @olivierlambert fragmentation does not matter with deduplication (at least how dedup is used in backup repos). i dont know why it does not work in your case. we do raw and not vhd. maybe thats a point. there can also be a problem when the guest-filesystem is zfs or btrfs because how those filystem alain their blocks.

                                          in general (with non ROW/COW guest fs) fragmentation should not do any harm. at least thats what we see at our customers backup repos. and they have windows and different linux guests. we do not use base templates so there should not be any hidden benefit of something.

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                                          • olivierlambertO Offline
                                            olivierlambert Vates 🪐 Co-Founder CEO
                                            last edited by

                                            We tested with VHD format, not with raw. We could do a test, but with raw you can't do deltas.

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