I have a pi4 running on an ssd over usb3 with a usb3 dock that has 2x2TB drives for storage.
At the moment I have mainly music on one and mainly video on the other, with important stuff on both and elsewhere.
Is it sensible to combine 2x2TB hdd’s via usb3 dock into a 4TB filesystem/pool/volume/thing…and if so can I have tiered storage so if one drive fails the other will have a mirror of important stuff?
Raid0 (combining both drives’ capacities) is not really tiered storage. You would want Raid1 (each drive is a copy of the other drive ), but doing this isn’t a backup. How will you be monitoring the drives so that you know if one of them actually fails?
I don’t think the RPi has a new enough kernel, but with bcachefs you can do tiered storage. By combining the storage of the ssd + hardrives, into a single block device, then make the ssd the read/write cache, and give the whole pool replicas=2, so that that if one drive dies you still have the failover of the other drive. Do be aware this setup is still not a backup however.
Thanks,
bcachefs could be the answer but I don’t really want my data on a fs I need this week’s kernel to access properly. Maybe I should just hold off for a few months.
I’m not monitoring the drives, I have backups of important stuff…but would be nice to tag more important stuff amongst the mediocre stuff on the off chance both drives don’t fail at the same time.
Totally reasonable, something like LVM can at least get you to a raid1 setup, pretty easily.