# Release notes for Gluster 3.11.1
This is a bugfix release. The release notes for [3.11.0](3.11.0.md), contains a
listing of all the new features that were added and bugs fixed, in the
GlusterFS 3.11 stable release.
## Major changes, features and limitations addressed in this release
### Improved disperse performance
Fix for bug [#1456259](https://bugzilla.redhat.com/1456259) changes the way
messages are read and processed from the socket layers on the Gluster client.
This has shown performance improvements on disperse volumes, and is applicable
to other volume types as well, where there maybe multiple applications or users
accessing the same mount point.
### Group settings for enabling negative lookup caching provided
Ability to serve negative lookups from cache was added in 3.11.0 and with
this release, a group volume set option is added for ease in enabling this
See [group-nl-cache](https://github.com/gluster/glusterfs/blob/release-3.11/extras/group-nl-cache) for more details.
### Gluster fuse now implements "-oauto_unmount" feature.
libfuse has an auto_unmount option which, if enabled, ensures that the file
system is unmounted at FUSE server termination by running a separate monitor
process that performs the unmount when that occurs. This release implements that
option and behavior for glusterfs.
Note that "auto unmount" (robust or not) is a leaky abstraction, as the kernel
cannot guarantee that at the path where the FUSE fs is mounted is actually the
toplevel mount at the time of the umount(2) call, for multiple reasons,
among others, see:
- fuse-devel: ["fuse: feasible to distinguish between umount and abort?"](http://fuse.996288.n3.nabble.com/fuse-feasible-to-distinguish-between-umount-and-abort-tt14358.html)
## Major issues
1. 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.
- Status of this bug can be tracked here, #1465123
## Bugs addressed
Bugs addressed since release-3.11.0 are listed below.
- [#1456259](https://bugzilla.redhat.com/1456259): limited throughput with disperse volume over small number of bricks
- [#1457058](https://bugzilla.redhat.com/1457058): glusterfs client crash on io-cache.so(__ioc_page_wakeup+0x44)
- [#1457289](https://bugzilla.redhat.com/1457289): tierd listens to a port.
- [#1457339](https://bugzilla.redhat.com/1457339): DHT: slow readdirp performance
- [#1457616](https://bugzilla.redhat.com/1457616): "split-brain observed [Input/output error]" error messages in samba logs during parallel rm -rf
- [#1457901](https://bugzilla.redhat.com/1457901): nlc_lookup_cbk floods logs
- [#1458570](https://bugzilla.redhat.com/1458570): [brick multiplexing] detach a brick if posix health check thread complaints about underlying brick
- [#1458664](https://bugzilla.redhat.com/1458664): [Geo-rep]: METADATA errors are seen even though everything is in sync
- [#1459090](https://bugzilla.redhat.com/1459090): all: spelling errors (debian package maintainer)
- [#1459095](https://bugzilla.redhat.com/1459095): extras/hook-scripts: non-portable shell syntax (debian package maintainer)
- [#1459392](https://bugzilla.redhat.com/1459392): possible repeatedly recursive healing of same file with background heal not happening when IO is going on
- [#1459759](https://bugzilla.redhat.com/1459759): Glusterd segmentation fault in ' _Unwind_Backtrace' while running peer probe
- [#1460647](https://bugzilla.redhat.com/1460647): posix-acl: Whitelist virtual ACL xattrs
- [#1460894](https://bugzilla.redhat.com/1460894): Rebalance estimate time sometimes shows negative values
- [#1460895](https://bugzilla.redhat.com/1460895): Upcall missing invalidations
- [#1460896](https://bugzilla.redhat.com/1460896): [Negative Lookup Cache]Need a single group set command for enabling all required nl cache options
- [#1460898](https://bugzilla.redhat.com/1460898): Enabling parallel-readdir causes dht linkto files to be visible on the mount,
- [#1462121](https://bugzilla.redhat.com/1462121): [GNFS+EC] Unable to release the lock when the other client tries to acquire the lock on the same file
- [#1462127](https://bugzilla.redhat.com/1462127): [Bitrot]: Inconsistency seen with 'scrub ondemand' - fails to trigger scrub
- [#1462636](https://bugzilla.redhat.com/1462636): Use of force with volume start, creates brick directory even it is not present
- [#1462661](https://bugzilla.redhat.com/1462661): lk fop succeeds even when lock is not acquired on at least quorum number of bricks
- [#1463250](https://bugzilla.redhat.com/1463250): with AFR now making both nodes to return UUID for a file will result in georep consuming more resources