We are pleased to announce the release of LizardFS 2.5.0.

This release adds several major features often requested by our users:
- high availbility of the whole filesystem
- disk space and inode quotas for users and groups
- POSIX Access Control Lists
- POSIX Extended Attributes
- I/O bandwidth limiting (globally and per-mountpoint)
- command line monitoring tool

Other improvements include:
- high performance CRC checksum implementation
- reduced overhead of hourly metadata backups


High availbility

LizardFS 2.5.0 includes the new 'shadow master' server which maintains
a current copy of filesystem metadata and is prepared to immediately
replace the master metadata server in case of a failure. This feature
combined with replication of file data allows LizardFS to remain fully
operational after crash of any particular machine in the cluster.

Shadow master obtains metadata updates from the master server using the
old MooseFS/LizardFS metalogger protocol. This facilitates no-downtime
upgrades from older version of LizardFS and from MooseFS 1.6.27.


Quotas

LizardFS 2.5.0 provides a quota mechanism similar to these found in
common UNIX filesystems. Filesystem administrator can define limits on
the number of files or amount of disk space owned by users and groups.

Quotas are controlled by special tools 'mfssetquota' and 'mfsrepquota',
which work analogously to the generic 'setquota' and 'repquota' tools.


POSIX Access Control Lists

ACLs allow fine-grained control over individual users' rights to read
or modify particular files and directories.

LizardFS 2.5.0 supports POSIX ACLs on Linux using the generic 'setfacl'
and 'getfacl' tools. This feature requires our modifed version of fuse
(kernel module and the library).


POSIX Extended Attributes

LizardFS 2.5.0 supports POSIX xattrs using generic tools.


I/O bandwidth limiting

LizardFS 2.5.0 provides an I/O bandwidth limiting mechanism integrated
with Linux cgroups. Applications reading from the filesystem are
grouped by their cgroup ID and the administrator can place limits on
bandwidth consumed to satisfy read and write requests from each group.

The limits can be enforced globally (across multiple mountpoints) or
locally (on one mountpoint).


Command line monitoring tool

LizardFS 2.5.0 introduces the new 'lizardfs-probe' command line tool
which queries the master server for various information concerning
filesystem health and activity.


High performance CRC checksum implementation

In LizardFS 2.5.0, we switched to a new, three times faster CRC
implementation to reduce latency and overhead of checksum calculations.


Reduced overhead of hourly metadata backups

LizardFS 2.5.0 provides a new metadata backup generation mechanism
which works fully in background and doesn't affect the master server.
