Backups v2

As I found myself with a new NAS, I started experimenting with TrueNAS capabilities. This was of course ZFS, but I was more interested in iSCSI.

My previous backup solution has done a great job keeping my homelab safe, but sadly it came with a cost: Over a terabyte is about 30 units with a retention of 3. That makes it harder to make sure I don’t overextend my current storage.

I therefore installed PBS(Proxmox Backup Server) and added a 1TiB iSCSI device to it from the new NAS. Then I fed it daily snapshots from almost all of my units. After almost a month it had accumulated almost 350 backups while using less than 450GB of storage space. The reason this works is of course compression, but most of it is due to deduplication. ZFS also has this feature, but PBS implemented it themselves because they handled cold data. Deduplication means that it takes the 4MB blocks it receives as backups, and only keeps the index of those blocks that it needs to restore. This also means that while doing a backup, it can do so incrementally, only transferring the changes.

How much space is saved? The deduplication score says 85, meaning a total of almost 38 TB is backed up, still compressed, but deduplicated.