question on PBS sync function

79corvette

New Member
Jun 20, 2023
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Hi,

I have a Proxmox VE machine running my home lab, and I just installed PBS on a separate machine on the same LAN and I am really liking it.

I have a third machine off-site running proxmox VE, and I just installed PBS into a container on that machine. What are the advantages of using the "Sync Jobs" function in PBS, versus just adding the second PBS instance to my Proxmox VE as another storage and running the backup job twice?

I'm not really concerned about VM/LXC downtime, as this is my homelab and the backups run when I am sleeping. There are no other users besides myself so taking each container down twice per night for 5 min instead of once for 5 min does not matter. I dont feel the need to encrypt the backups on my local PBS instance, but the remote machine is several states away on a network and PVE host I do not control, so I will be encrypting backups sent to that machine and I dont think I can do that with a sync job. It would need to be encrypted both places or neither.

Anything I am missing here?
Thanks!
 
Hi,

I have a third machine off-site running proxmox VE, and I just installed PBS into a container on that machine. What are the advantages of using the "Sync Jobs" function in PBS, versus just adding the second PBS instance to my Proxmox VE as another storage and running the backup job twice?
the main advantage of running a sync job from one PBS instance to another one is reduced load on the PVE host (which you don't care about, as stated). Other advantages are the possible access right separation, which you can setup using the ACLs.

I dont feel the need to encrypt the backups on my local PBS instance, but the remote machine is several states away on a network and PVE host I do not control, so I will be encrypting backups sent to that machine and I dont think I can do that with a sync job. It would need to be encrypted both places or neither.
Yes, when using the sync job, also the initial backup snapshot has to be encrypted. This is because the encryption is done client side, not server side. Also, the sync job does not care about the type and contents of the backup. It just syncs snapshot metadata and their associated chunks from one datastore to the other one.

In your case, it can definitely make sense to run 2 independent backup jobs for the local and remote backup target.

Note however, if you have VMs and want to back them up in snapshot mode utilizing the dirty bitmap, than you will have invalidation of the bitmap if the last backup was performed on the other backup storage.
 
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Hi,


the main advantage of running a sync job from one PBS instance to another one is reduced load on the PVE host (which you don't care about, as stated). Other advantages are the possible access right separation, which you can setup using the ACLs.


Yes, when using the sync job, also the initial backup snapshot has to be encrypted. This is because the encryption is done client side, not server side. Also, the sync job does not care about the type and contents of the backup. It just syncs snapshot metadata and their associated chunks from one datastore to the other one.

In your case, I can definitely make sense to run 2 independent backup jobs for the local and remote backup target.

Note however, if you have VMs and want to back them up in snapshot mode utilizing the dirty bitmap, than you will have invalidation of the bitmap if the last backup was performed on the other backup storage.

Thanks Chris for your detailed reply. This answers all my questions. Much appreciated!