5 ms·
> The dm layer gives you cow/snapshots for any filesystem you want already and has for more than a decade. Some implementations actually use it for clever trick
by pdimitar 1y ago
> The dm layer gives you cow/snapshots for any filesystem you want already and has for more than a decade. Some implementations actually use it for clever trickery like updates, even.
O_o
Apparently I've been living under a rock, can you please show us a link about this? I was just recently (casually) looking into bolting ZFS/BTRFS-like partial snapshot features to simulate my own atomic distro where I am able to freely roll back if an update goes bad. Think Linux's Timeshift with something little extra.
- tux3 1y agoThere are downsides to adding features in layers, as opposed to integrating them with the FS, but dm can do quite a lot: https://docs.kernel.org/admin-guide/device-mapper/snapshot.html https://docs.kernel.org/admin-guide/device-mapper/snapshot.h...
- deleted 1y ago[deleted]
- tptacek 1y agoDM has targets that facilitate block-level snapshots, lazy cloning of filesystems, compression, &c. Most people interact with those features through LVM2. COW snapshots are basically the marquee feature of LVM2.