PBS - Backup Storage

[spetrillo]

Hello all,

My PBS has a 256 gig NVMe drive in it and I do not want to use it as my backup storage. I would like to mount storage from my Synology NAS, to be used for the backup storage. Synology can present this storage in many different formats. I can use SMB, NFS, or even iSCSI. I am leaning towards iSCSI since it is still block level storage. What would be your choice?

Thanks,
Steve

 

[complexplaster27]

I believe all you need to do is create a folder somewhere and mount the Storage to it using the terminal.
Then once you've verified that it's mounted correctly go to the GUI and add it as a Datastore by entering in the location of mount as the backing path.

But do make a new folder inside the mount for the datastore to avoid filling up the root of the drive with 65k chunk folders.

 

[Dunuin]

Don't forget that PBS needs IOPS performance. For example, a GC task needs to read and write millions over millions of chunk files in random order.
So any non-local storage won't be great because of the additional latency of the network. Especially not great, in case your NAS is using HDDs and not SSD.
Will work, but don't expect much (like your NAS being usable for anything else when all HDDs are working at 100% for hours or days doing the GC/re-verify tasks).

In case of NFS/SMB, make sure the network share is mounted so that the "backup" user (UID 34) got write access and that the NAS got atime or relatime enabled. Beside that, PBS will accept and work with anything as long as it offers to store a posix-compatible folder.

 

[spetrillo]

Don't forget that PBS needs IOPS performance. For example, a GC task needs to read and write millions over millions of chunk files in random order.
So any non-local storage won't be great because of the additional latency of the network. Especially not great, in case your NAS is using HDDs and not SSD.
Will work, but don't expect much (like your NAS being usable for anything else when all HDDs are working at 100% for hours or days doing the GC/re-verify tasks).

In case of NFS/SMB, make sure the network share is mounted so that the "backup" user (UID 34) got write access and that the NAS got atime or relatime enabled. Beside that, PBS will accept and work with anything as long as it offers to store a posix-compatible folder.

Let me ask this question...is there functionality to migrate backups from local storage to cheaper slower storage? I could use the iSCSI mount as my migration target, so I do not need IOPS performance there, just large capacity.

 

[Dunuin]

Let me ask this question...is there functionality to migrate backups from local storage to cheaper slower storage? I could use the iSCSI mount as my migration target, so I do not need IOPS performance there, just large capacity.

You could have two datastores and do a local sync to a slower storage. But won't help, as the datastore on the slow storage would need to run GC/re-verify as well.

 

[spetrillo]

So then I might have to use the 1TB NVMe drive...thats quite disappointing. I have TBs of NAS storage but cannot really use it in any scenario. OK so going with the 1TB NVMe drive....can I partition it so the OS and pieces are on one partition and the actual directory storage for the backups is on another partition on the same drive? If yes how big does the OS partition need to be? Is there a Proxmox document that talks about these options?

 

[carles89]

Hi,

You can find recommended requirements for OS drive here: https://pbs.proxmox.com/docs/installation.html#recommended-server-system-requirements

The easiest way to go is to use two small mirrored drives for boot and two 1TB mirrored NVMe drives as a datastore.

If you cannot use dedicated drives for booting, you should be able to install PBS using only a part of the storage (i.e. 64GB). It is possible thanks to the hdsize parameter of the installer [1]. Then, create two empty partitions on each disk using the remaining space and create a mirrored ZFS pool to use as a datastore [2].

Here is an example for a mirrored pool:

zpool create -f -o ashift=12 <pool> mirror <device1> <device2>

On <device1> and <device2> you'll have to use the partition you've previously created (i.e. /dev/sda3 /dev/sdb3). Do not use the entire device name, because it will be wiped.

[1] https://pve.proxmox.com/wiki/Installation#:~:text=for more details.-,hdsize,-Defines the total
[2] https://pbs.proxmox.com/docs/sysadmin.html#create-a-new-pool-with-raid-1

 

[wahmed]

If your Synology NAS sitting useless and you cannot use it for anything else, it makes sense to use it to store your backups via a NFS or iSCSI mountpoint. Yes it wont be the best performing backup server but your scenario looks like you dont have very large backup needs into several terabytes.

When a datastore mounted from elsewhere, it is also possible to virtualize the PBS itself since it will not hold the actual backup data. Saves from dedicating a physical node. You can always test the performance and see if it is acceptable since you already have everything. Note that iSCSI probably will provide slightly better performance than NFS.

 

[spetrillo]

If your Synology NAS sitting useless and you cannot use it for anything else, it makes sense to use it to store your backups via a NFS or iSCSI mountpoint. Yes it wont be the best performing backup server but your scenario looks like you dont have very large backup needs into several terabytes.

When a datastore mounted from elsewhere, it is also possible to virtualize the PBS itself since it will not hold the actual backup data. Saves from dedicating a physical node. You can always test the performance and see if it is acceptable since you already have everything. Note that iSCSI probably will provide slightly better performance than NFS.

Now this is interesting. I had not thought long and hard about virtualizing my PBS but I could do that and do an iSCSI mount to provide it the datastore storage. Maybe it's not ideal but it allows me to take advantage of 3TB+ of NAS storage doing nothing.

 

[carles89]

Take into account that a slow backup destination can lead to VM corruption due to how backup is implemented in PVE[1][2]. There's an upcoming feature (backup fleecing) that will solve it, but it is still in development[3].

I'd advise against use nothing but local storage in PBS.

If your Synology NAS is a plus model, you can use ActiveBackup for Business, which runs on the NAS itself and works with spinning disks.

[1] https://forum.proxmox.com/threads/vms-freezing-and-unreachable-when-backup-server-is-slow.96521/
[2] https://git.proxmox.com/?p=pve-qemu.git;a=blob_plain;f=backup.txt
[3] https://bugzilla.proxmox.com/show_bug.cgi?id=4136