running time for a full fsck. It also reduces the random access time
for large files and speeds the traversal time for directory tree walks.
The key idea is to reserve a small area in each cylinder group
immediately following the inode blocks for the use of metadata,
specifically indirect blocks and directory contents. The new policy
is to preferentially place metadata in the metadata area and
everything else in the blocks that follow the metadata area.
The size of this area can be set when creating a filesystem using
newfs(8) or changed in an existing filesystem using tunefs(8).
Both utilities use the `-k held-for-metadata-blocks' option to
specify the amount of space to be held for metadata blocks in each
cylinder group. By default, newfs(8) sets this area to half of
minfree (typically 4% of the data area).
This work was inspired by a paper presented at Usenix's FAST '13:
www.usenix.org/conference/fast13/ffsck-fast-file-system-checker
Details of this implementation appears in the April 2013 of ;login:
www.usenix.org/publications/login/april-2013-volume-38-number-2.
A copy of the April 2013 ;login: paper can also be downloaded
from: www.mckusick.com/publications/faster_fsck.pdf.
Reviewed by: kib
Tested by: Peter Holm
MFC after: 4 weeks
These tools declare global variables without using the static keyword,
even though their use is limited to a single C-file, or without placing
an extern declaration of them in the proper header file.
zero and thus report as having been made in January 1970. Apart
from looking a bit silly, it also triggers alarms from scripts
that detect weird time stamps. This update sets all 4 (or 3, in
the case of UFS1) time stamps to the current time when enabling
journaling during newfs or later when enabling it with tunefs.
Reported by: Hans Ottevanger <hans@beastielabs.net>
MFC after: 1 week
operate on one type of filesystem, mention this.
While here, capitalise the use of "UFS" in growfs.8 to match other uses of
the term in other man pages.
MFC after: 1 week
the fragment, and write the full block. Reading less might not work
due to device sector size bigger then size of direntries in the
last directory fragment.
Reported by: bz
In collaboration with: pho
Reviewed by: jeff
Tested by: bz, pho
Reported by: Mikolaj Golub <to.my.trociny@gmail.com>
- Only require 256k of blocks per-cg when trying to allocate contiguous
journal blocks. The storage may not actually be contiguous but is at
least within one cg.
- When disabling SUJ leave SU enabled and report this to the user. It
is expected that users will upgrade SU filesystems to SUJ and want
a similar downgrade path.
structure so that we correctly reload. Note that tunefs doesn't
properly detect the need to reload if the disk device is specified
for a read-only mounted filesystem.
- Lessen the contiguity requirement for the journal so that it is more
likely to succeed.
brings in support for an optional intent log which eliminates the need
for background fsck on unclean shutdown.
Sponsored by: iXsystems, Yahoo!, and Juniper.
With help from: McKusick and Peter Holm
