Red Hat Training
A Red Hat training course is available for Red Hat Enterprise Linux
Chapter 9. File Systems
XFS runtime statistics are available per file system in the /sys/fs/
directory
The existing XFS global statistics directory has been moved from the
/proc/fs/xfs/
directory to the /sys/fs/xfs/
directory while maintaining compatibility with earlier versions with a symbolic link in /proc/fs/xfs/stat
. New subdirectories will be created and maintained for statistics per file system in /sys/fs/xfs/
, for example /sys/fs/xfs/sdb7/stats
and /sys/fs/xfs/sdb8/stats
. Previously, XFS runtime statistics were available only per server. Now, XFS runtime statistics are available per device. (BZ#1269281)
A progress indicator has been added to mkfs.gfs2
The
mkfs.gfs2
tool now reports its progress when building journals and resource groups. As mkfs.gfs2
can take some time to complete with large or slow devices, it was not previously clear if mkfs.gfs2 was working correctly until a report was printed. A progress bar has been added to mkfs.gfs2
indicate progress. (BZ#1196321)
fsck.gfs2 has been enhanced to require considerably less memory on large file systems
Prior to this update, the Global File System 2 (GFS2) file system checker, fsck.gfs2, required a large amount of memory to run on large file systems, and running fsck.gfs2 on file systems larger than 100 TB was therefore impractical. With this update, fsck.gfs2 has been enhanced to run in considerably less memory, which allows for better scalability and makes running fsck.gf2 practical to run on much larger file systems. (BZ#1268045)
GFS2 has been enhanced to allow better scalability of its glocks
In the Global File System 2 (GFS2), opening or creating a large number of files, even if they are closed again, leaves a lot of GFS2 cluster locks (glocks) in slab memory. When the number of glocks was in the millions, GFS2 previously started to slow down, especially with file creates: GFS2 became gradually slower to create files. With this update, the GFS2 has been enhanced to allow better scalability of its glocks, and the GFS2 can now therefore maintain good performance across millions of file creates. (BZ#1172819)
xfsprogs rebased to version 4.5.0
The xfsprogs packages have been upgraded to upstream version 4.5.0, which provides a number of bug fixes and enhancements over the previous version. The Red Hat Enterprise Linux 7.3 kernel RPM requires the upgraded version of xfsprogs because the new default on-disk format requires special handling of log cycle numbers when running the
xfs_repair
utility. Notable changes include:
- Metadata cyclic redundancy checks (CRCs) and directory entry file types are now enabled by default. To replicate the older
mkfs
on-disk format used in earlier versions of Red Hat Enterprise Linux 7, use the-m crc=0 -n ftype=0
options on themkfs.xfs
command line. - The
GETNEXTQUOTA
interface is now implemented inxfs_quota
, which allows fast iteration over all on-disk quotas even when the number of entries in the user database is extremely large.
Also, note the following differences between upstream and Red Hat Enterprise Linux 7.3:
- The experimental sparse inode feature is not available.
- The free inode btree (finobt) feature is disabled by default to ensure compatibility with earlier Red Hat Enterprise Linux 7 kernel versions. (BZ#1309498)
The CIFS kernel module rebased to version 6.4
The Common Internet File System (CIFS) has been upgraded to upstream version 6.4, which provides a number of bug fixes and enhancements over the previous version. Notably:
- Support for Kerberos authentication has been added.
- Support for
MFSymlink
has been added. - The
mknod
andmkfifo
named pipes are now allowed.
Also, several memory leaks have been identified and fixed. (BZ#1337587)
quota
now supports suppressing warnings about NFS mount points with unavailable quota
RPC service
If a user listed disk quotas with the
quota
tool, and the local system mounted a network file system with an NFS server that did not provide the quota
RPC service, the quota
tool returned the error while getting quota from server
error message. Now, the quota
tools can distinguish between unreachable NFS server and a reachable NFS server without the quota
RPC service, and no error is reported in the second case. (BZ#1155584)
The /proc/
directory now uses the red-black tree implementation to improve the performance
Previously, the
/proc/
directory entries implementation used a single linked list, which slowed down the manipulation of directories with a large number of entries. With this update, the single linked list implementation has been replaced by a red-black tree implementation, which improves the performance of directory entries manipulation. (BZ#1210350)