Continuous Replication and snapshots together



  • Hi

    I'm about to setup CR. I have a question about snapshots. I'm the man who don't trust the CR, so be patient.

    I have these simple assumptions on this:

    • make optimal setup
    • no to make quirk setup
    • make setup that will not break my VM
    • I want to avoid any unnecesary snapshot on the VM (multiple CR backups)

    What I want to achieve is CR backup from XCP01 to XCP02

    • CR retention: 5, time range: 24h (CR from 8:00 to 16:00)
    • Also have 5 dialy snapshot of the VM on XCP01 server (5 days retention)

    Is this a problem to have eg.5 snapshots of the VM on XCP01 while CR-ing to XCP02?

    Second part, is it tricky or simple? As You can see on my professional diagram I want also to backup the VM to the two Backup servers, which are OnLine alternately. B01 is ON on the 1st and 3rd week of the month, B02 on the 2nd and 4th. So at the end I can "go back" to almost one month back.

    • Backup retention on the backup servers: 3

    • How to setup this backup?

    • will it break?

    • how many additional snapshot I'll have on source VM becouse of the multiple CR backups?

    • can I set only one CR backup task for the rotating backup servers?

    056d5126-d149-44b9-93e5-7f1fb15e88d0-image.png


  • XCP-ng Team

    This is a question for XO team. Ping @badrAZ


  • XO Team

    Hi,

    For your first question, created snapshots will not interfere with the CR.
    For your last question, by design and performance, you can' t set one CR for rotating servers.

    So, you need:

    • one CR with enabled Rolling Snapshot which will backup your VM from XCP01 to XCP02 and will create 5 snapshots.
    • two CRs one will backup your VM from XCP01 to B01 and the second will backup it from XCP01 to B02. These jobs will create 2 snapshots.

    Total snapshots created by these jobs: 7



  • @badrAZ @olivierlambert
    Thanks for quick reply, I'm bulding test env, I will report back with the results.



  • @badrAZ said in Continuous Replication and snapshots together:

    one CR with enabled Rolling Snapshot which will backup your VM from XCP01 to XCP02 and will create 5 snapshots.

    I need clarification for this part - Indeed I can enable snapsoth together with CR - even didn't know it's possible but I don't understand how it works? I need to have 5 snapshot of the VM on XCP01 - snapshot sould be made everyday at 6:00. By what schedule snapshots will be made when I enable rolling snap alog with CR backup? It will be the CR sheldue? So for what I want to achieve I should create separate task for create snapshots of the VM on XCP01?


  • XO Team

    If you wan't your CR to be done in the same time with the Rolling snapshot you only need one schedule with 5 as Replication retention and 5 as Snapshot retention.

    If you want them to be executed in different time better create two jobs instead of two schedules because it have a known issue with this case which the patch will be released soon.



  • @badrAZ said in Continuous Replication and snapshots together:

    because it have a known issue

    I know it 😉 can You share the details?


  • XO Team

    The CR is a functionality which exports the VM at the first time then it exports only the diff for optimization.

    This functionality needs a snapshot to be kept on the VM. Unfortunately when a job contains two schedules which one is for CR, one schedule will delete the snapshot created by the CR then the CR will always export the full VM instead of the diffs.



  • Thanks for info,

    So in my case in order to keep 5 snaps of the VM on XCP01, I need to create separate rolling snap schedule? Will creating snaps of the VM on XCP01 interfere somehow with CR of the VM from XCP01 to XCP02 or it's totally safe?


  • XO Team

    If you create two separated jobs. One for the CR and one for the Rolling snapshot they will not interfere.


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