I am building my 3-2-1 backup system and wanted to add an external HD to my TrueNAS machine. Since it only works with ZFS, I thought of setting up that drive as a compressed, dedup ZFS volume.
I have a truckload of NVMe left on the boot drive that I could repartition and turn some of the free space as a dedup vdev for the backup drive. I don’t have any other physical bays to add a dedicated drive on the machine.
A) Is that a bad idea? What are the downsides of using the boot drive like that?
B) Which tool do you recommend for local backup? I’m looking for actual incremental backup, not just a sync tool.
borgbackup
For local backup I like rsnapshot. It’s a script that uses rsync and hard links to create incremental backups.
The thing about it is that it’s super simple and easy to restore from since you just get a bunch of directories like “daily.0” and “daily.1”. To restore you just find the files you want with standard tools like find and locate and just copy files out.
There are other more advanced tools like restic, borg, duplicacy, etc. I use things like that for the off-site backups (I backup the “daily.0” directory from my rsnapshot backups).
Restic is my tool of choice for deduplicated encrypted verifiable compressed incremental backups.
In that case, what would be better in terms of memory / CPU usage: dedup and compression at the filesystem level or disabling it and doing it at the tool level?
You can’t dedup/compress restic repos at fs level due to the encryption.
Nice thing is you get those even with „dumb“ targets that can‘t do those for you.