Score:3

Pooled storage with varying redundancy per file system

kz flag

I have some files that I want stored mirrored. I have some files that I only need single copies (i.e. scratch data, easily regenerated data, etc). And I have some files that are so critical, I want it mirrored in triplicate so I can handle a 2-disk failure. These sets of data are separated into different directories and could be different fs/volumes/etc.

I want to also thinly provision the data across a pool of disks so that I can expand the pool later, because I don't know how much space each thing will require.

ceph can handle this, but I don't have multiple nodes. I'm only concerned with data recoverability, not high availability, so I don't have the need for something as complex as ceph.

Are there other tools / systems for Linux that can do this? From a cursory look, it seems lvm, btrfs, and zfs all can't do this because they specify their redundancy on a per-disk-in-pool basis, not a per-volume basis.

Score:1
ca flag

lvmraid can fo that, as enables you to specify RAID level (and redundancy) per-volume.

For example, to create a RAID 1 volume (as shown in the man page):

lvcreate --type raid1 [--mirrors Number] VG [PVs]

If redundancy is not necessary a RAID 0 can be created on the same volume group:

lvcreate --type raid0 [--stripes Number --stripesize Size] VG [PVs]
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