This is a bugfix release. The Release Notes for 3.12.0, 3.12.1 contain a listing of all the new features that were added and bugs fixed in the GlusterFS 3.12 stable release.
No Major changes- Expanding a gluster volume that is sharded may cause file corruption
- Sharded volumes are typically used for VM images, if such volumes are expanded or possibly contracted (i.e add/remove bricks and rebalance) there are reports of VM images getting corrupted.
- The last known cause for corruption (Bug #1465123) has a fix with this release. As further testing is still in progress, the issue is retained as a major issue.
- Status of this bug can be tracked here, #1465123
A total of 12 patches have been merged, addressing 11 bugs- #1486538: [geo-rep+qr]: Crashes observed at slave from qr_lookup_sbk during rename/hardlink/rebalance
- #1486557: Log entry of files skipped/failed during rebalance operation
- #1487033: rpc: client_t and related objects leaked due to incorrect ref counts
- #1487319: afr: check op_ret value in __afr_selfheal_name_impunge
- #1488119: scripts: mount.glusterfs contains non-portable bashisms
- #1488168: Launch metadata heal in discover code path.
- #1488387: gluster-blockd process crashed and core generated
- #1488718: [RHHI] cannot boot vms created from template when disk format = qcow2
- #1489260: Crash in dht_check_and_open_fd_on_subvol_task()
- #1489296: glusterfsd (brick) process crashed
- #1489511: return ENOSYS for 'non readable' FOPs