The original post: /r/datahoarder by /u/Pyryara on 2025-05-29 11:19:27.
I currently have a raid10 setup with 6x3TB drives, of which one has recently failed, and an additional raid1 mirror of two 13TB drives. Instead of getting a replacement 3TB drive, I want to get away from this towards a snapraid setup, because the main data I store on my small N100 home server is large unchanging media files, of which I simply want to have a backup without being totally wasteful of space.
I have understood that with 5+ drives I should probably go for two parity drives for my data, but since I only have two larger drives, that's of course not easily possible. So I was thinking if I could maybe divide the 13 TB drives into 10+3 TB, and then I'd pool the 3 TB partitions into a snapraid with the 6 other drives, and then do a single-parity snapraid with the 10 TB partitions on the larger drives. This would also allow me to change the setup quite easily in the future if I replace further 3 TB drives with larger 13 TB drives.
So as a poorly drawn ASCII representation, it would look a bit like this:
SnapRAID Pool (1 Data + 1 Parity = 10 TiB Usable)
(Protects D6)
________|___________
/ \
Disk 1 Disk 2 Disk 3 Disk 4 Disk 5 Disk 6 Disk 7
(2.7T) (2.7T) (2.7T) (2.7T) (2.7T) (12.7T) (12.7T)
+---------+---------+---------+---------+----------+-------------+-------------+
| | | | | | | |
| | | | | | | |
| | | | | | | |
| | | | | | Parity R | Data |
| N/A | N/A | N/A | N/A | N/A | (SR R) | (D6) |
| | | | | | (~10 TiB) | (~10 TiB) |
| | | | | | | |
| | | | | | | |
| | | | | | | |
|---------|---------|---------|---------|----------+-------------+-------------+
| Data | Data | Data | Data | Parity P | Data | Parity Q |
| (D1) | (D2) | (D3) | (D4) | (SR P) | (D5) | (SR Q) |
| (2.7 T) | (2.7 T) | (2.7 T) | (2.7 T) | (2.7 T) | (2.7 T) | (2.7 T) |
+---------+---------+---------+---------+----------+-------------+-------------+
\_____________________________________________________________/
|
SnapRAID Pool (5 Data + 2 Parity = 13.5 TiB Usable)
(Protects D1-D5)
In the end, this would give me a total of 23.5 TiB of space with my existing drives. While the larger drives are effectively in two snapraids at the same time, I would make sure with this setup that no drive has two data or parity partitions, so there will never be contentious read/writes during snapraid operations.
My question is: is this a clever idea, or a horrible one? Do you have a different proposition about what I should do with my still working 5x3TB + 2x13TB drives?
(EDIT: restored the ASCII formatting, Reddit at first removed most spaces lol)