Ping @lsouai-vates

@DustinB OK. I think I'm between a rock and a hard place! Thanks for the advice.

Ah great! It should be documented I suppose, ping @thomas-dkmt

@MathieuRA Thank you!

@frank-s Think of it like this... You take the original backup with snapshot on October 1st. You then have a differential backup on October 8th. That differential only writes the changes that make the state of the server on October 8th different (hence the term differential) from the state of the server as it was on the full snapshot on October 1st. Now you delete the snapshot of the full system state taken on October 1st, leaving only the October 8th differential. It's now October 15th and you want to restore something from the October 8th differential and you figure you'll just make a new full snapshot from October 15th and then try to apply the October 8th differential. However, this won't work because the differential from October 8th will be missing key reference points it will be looking for in order to overlay its changes onto the snapshot. What else on that server changed from October 1st to October 15th that isn't contained in the differential? What changes occurred from October 8th to October 15th that are newer than what is on the differential? You could, potentially, brick your entire system if the differential started overwriting changes it sees from its system state that are actually newer than the data it contains. Differentials are entirely dependent on the full snapshot on which they are based. Any new snapshot taken after their creation will be totally foreign to the differential... those differentials will be looking for very specific system states that existed at the time the original snapshot was created, and those will be completely different from the system state as it will appear on a new snapshot created after the differential.

Thanks for your replies. Since the advent of mirror backups I realised there was an opportunity to backup to several different USB disks where each disk is a different remote allowing rotation of the disks. The primary backup goes to additional internal storage which is then mirrored to the USB disks. Only one snapshot per vm is needed regardless of how many USB disks are in use. To do this I need to script the mounting process for these disks and send notification emails when a disk is mounted, unmounted (safe to unplug) or when no disk could be found. This is my use case. Thanks

@florent Thank you for the update.

@florent I've been away for a few days so sorry for not replying sooner. Thank you all for your advice. I have still been unable to set up encryption on an s3 remote. I even tried a different provider (iDrive e2) but got the same error. I did manage to do it with backblaze b2 but the download speed for restore was too slow. I take onboard planedrop's point about https encrypting data in flight so if I proceed in production I will use the encryption tools provided by the s3 provider and ensure I always use https. Having said that I will probably wait till the s3 remote is no longer in beta. Once again thanks everyone.

@florent Clear now, thanks!

And I'd like to keep it like that It's very important!

@florent said in Mirror backup with Continuous Replication: Backup from Storage Repository 2 to Backup Repository (Remote) We are looking at a similar setup. We currently do continuous replication from one host to another host and then want to take a weekly backup off from SR2 effectively to a NAS. Looking at one of these jobs, there is 31 days retention, and a fullbackup every 20 days. Is there a way I can match only the latest backup automatically so I can off-site just that to the NAS, and it come out as a full-backup, as I don't need to take 31 days worth, just the latest. I could adjust the full-backup interval perhaps to help with this and just take the most recent full backup although I don't think there is a tag for those? SR2 on the second host also has live VM's running on it as well as being a CR target. Or is there another way I can achieve this? I could take a backup directly from the running VM/SR1 direct to the NAS but I think that would interfere with the CR snapshot chain? Thanks, John

Thank you

@Danp Thanks for pointing me in the right direction. I was following an older howto where --global was not specified. That was my first problem - now fixed! Second problem was that I had installed into the root directory of Centos7 so the paths for creating the links were different. Once I had found the correct paths and created the links all was good. Thanks again. Frank.