Add the extended options packed_meta_blocks and journal_location_front
which causes mke2fs to place the metadata blocks at the beginning of
the file system.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
In practice, it is **extremely** rare for users to try to use more
than the first backup superblock located at the beginning of block
group #1. (i.e., at block number 32768 for file systems with a 4k
block size). This new compat feature restricts the backup superblock
to block group #1 and the last block group in the file system.
Aside from reducing the overhead of the file system by a small number
of blocks, by eliminating the rest of the backup superblocks, it
allows us to have a much more flexible metadata layout. For example,
we can force all of the allocation bitmaps and inode table blocks to
the beginning of the disk, which allows most of the disk to be
exclusively used for contiguous data blocks.
This simplifies taking advantage of certain HDD specific features,
such as Shingled Magnetic Recording (aka Shingled Drives), and the
TCG's OPAL Storage Specification where having a simple mapping between
LBA block ranges and the data blocks used by the file system can make
life much simpler.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The mke2fs(8) man page was updated in 4727c67dc2, but needs some
more clear descriptions for extra_isize and metadta_csum features.
The uninit_bg feature is supported by all ext4-capable kernels,
and does have a slow e2fsck pass for newly-formatted filesystems,
so remove the caveat.
Signed-off-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
I've added documentation for all available filesystem features
settable by mke2fs.
* Features now include the kernel constant attached to the function.
* Some pre-existing feature explanations have been expanded based on
ext4.wiki.kernel.org.
[ Edited by tytso for stylistic and correctness. ]
Addresses-Debian-Bug: #586218
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The man page still said it was not possible to change the number of
inodes on a filesystem after creating it. You actually can by
resizing the fs, so clarify this language a bit.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
If quota isn't turned on with --enable-quota, then comment
quota documentation out of the mke2fs manpage.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Don't change the root directory's UID/GID automatically just because
mke2fs was run as a non-root user. This can be confusing for users,
and is not flexible for non-root installation tools that need to
create a filesystem with different ownership from the current user.
Add the "-E root_owner[=uid:gid]" option to mke2fs so that the user
and group can be explicitly specified for the root directory. If
the "=uid:gid" argument is not specified, the current UID and GID
are extracted from the running process, as was done in the past.
Signed-off-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Bigalloc feature has been used for a long time, but the documentation
in mke2fs is still missing. So add it.
Addresses-Debian-Bug: #669730
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
We print "extents" for the feature, so we should document "extents" in
the mke2fs's man page, even though we accept both "extent" and
"extents".
Addresses-Sourceforge-Bug: #3559210
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This can be useful when using mke2fs on loaded servers, since
otherwise mke2fs can dirty a huge amount of memory very quickly,
leading to other applications not being happy at all.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
mke2fs was creating both user and group quota inodes on enabling
the quota feature. This patch adds the extended option 'quotatype'
that can be used to exclusively specify the quota type that the
user wants to initialize.
# Ex: Default behavior without extended option creates both
# user and group quota inodes:
$ mke2fs -t ext4 -O quota /dev/ram1
# To enable only user quotas:
$ mke2fs -t ext4 -O quota -E quotatype=usr /dev/ram1
# To enable only group quotas:
$ mke2fs -t ext4 -O quota -E quotatype=grp /dev/ram1
Signed-off-by: Aditya Kali <adityakali@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Multi-mount protection is feature that allows mke2fs, e2fsck, and
others to detect if the filesystem is mounted on a remote node (on
SAN disks) and avoid corrupting the filesystem. For e2fsprogs this
means that it checks the MMP block to see if the filesystem is in use,
and marks the filesystem busy while e2fsck is running on the system.
This is useful on SAN disks that are shared between high-availability
servers, or accessible by multiple nodes that aren't in HA pairs. MMP
isn't intended to serve as a primary HA exclusion mechanism, but as a
failsafe to protect against user, software, or hardware errors.
There is no requirement that e2fsck updates the MMP block at regular
intervals, but e2fsck does this occasionally to provide useful
information to the sysadmin in case of a detected conflict.
For the kernel (since Linux 3.0) MMP adds a "heartbeat" mechanism to
periodically write to disk (every few seconds by default) to notify
other nodes that the filesystem is still in use and unsafe to modify.
Originally-by: Kalpak Shah <kalpak@clusterfs.com>
Signed-off-by: Johann Lombardi <johann@whamcloud.com>
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
mke2fs also creates quota inodes (userquota: inode# 3 and
groupquota: inode #4) inodes while creating a filesystem when 'quota'
feature is set.
# To set quota feature and initialize quota inodes during mke2fs:
$mke2fs -t ext4 -O quota /dev/ram1
Signed-off-by: Aditya Kali <adityakali@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
For consistency with other multi-word options, document the extended
option stripe_width instead of stripe-width. This also avoids the
complexity of parsing options that have an embedded '-'.
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Add the ability to skip zeroing journal blocks on disk. This can
significantly speed up mke2fs with large journals. At worst the
uninitialized journal is only a very short-term risk (if at all),
because the journal will be overwritten on any new filesystem as
soon as any significant amount of data is written to disk, and
the new journal TID would need to match the offset/TID of an old
commit block still left on disk.
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
It is not true that 'nodiscard' is set as default, so remove this
sentence. The default is 'discard' and it is properly documented in man
page.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The commit 493024ea1d ("mke2fs: Fix up the
fs type and feature selection for 64-bit blocks") added 'big' and 'huge'
usage-type but was missing description in man page. Add it.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
It would be nice to have consistent "discard" options in every system
tool (mount, fsck, mkfs) taking advantage of discards. Also "discard"
and "nodiscard" is more descriptive instead of just "-K" and can be
easily defaulted and it is something we can not do with "-K".
With this commit you need to specify extended option like this:
./mke2fs -T <fstype> -E nodiscard <device>
in order make a filesystem without discarding the device first. And
./mke2fs -T <fstype> -E discard <device>
respectively.
-K option is with this commit deprecated and should not be used anymore.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This bit of the mke2fs manpage is slightly confusing:
-b block-size
Specify the size of blocks in bytes. <snip>
If block-size is negative, then mke2fs will use heuristics
to determine the appropriate block size, with the constraint
that the block size will be at least block-size bytes.
because it sounds like the block size will be at least a negative
number. Clarify just what the negative sign means.
Reported-by: Chris Frost <chris@frostnet.net>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Try calling the BLKDISCARD ioctl at mkfs time to pre-discard all blocks
on an ssd, or a thinly-provisioned storage device.
No real error checking; if it fails, it fails, and that's ok - it's
just an optimization. Also, it cannot work in conjunction with
the undo io manager, for obvious reasons.
Optionally disabled with a "-K" (mnemonic: Keep) option.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Add a more explicit description of how specifying the flex_bg file
system feature changes the layout of the per-block group metadata.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The e2fsprogs programs have historically just said that they operate
on ext2 and ext3 file system in their man pages. Update them to say
that they also operate on ext4 file systems.
Addresses-Launchpad-bug: #381854
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Thanks to A. Costa for pointing these out.
Addresses-Debian-Bug: #498100
Addresses-Debian-Bug: #498101
Addresses-Debian-Bug: #498102
Addresses-Debian-Bug: #498103
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Option specifiers must be escaped so the are printed as minus signs
(U+002D) instead of hyphens (U+2010). Hence "mke2fs -t ext4" must be
expressed as "mke2fs \-t ext4" instead.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Also add the missing argument of the -M option, replace the mistaken
[libdefaults] section header with [defaults], and slightly rephrase
two or three sentences.
Signed-off-by: Benno Schulenberg <bensberg@justemail.net>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Change the way we allocate bitmaps and inode tables if the FLEX_BG
feature is used at mke2fs time. It places calculates a new offset for
bitmaps and inode table base on the number of groups that the user
wishes to pack together using the new "-G" option. Creating a
filesystem with 64 block groups in a flex group can be done by:
mke2fs -j -I 256 -O flex_bg -G 32 /dev/sdX
Signed-off-by: Jose R. Santos <jrs@us.ibm.com>
Signed-off-by: Valerie Clement <valerie.clement@bull.net>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Instead of using -O lazy_bg,uninit_bg as the way of requesting that
the inode table be lazy unitialized, use the parameter
lazy_itable_init, which can either be set via mke2fs's -E option, or
via /etc/mke2fs.conf.
Also fix some random problems in mke2fs's man page, including
documenting the extent feature, which had been missing.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Allow the old name of uninit_groups when converting feature names for
backwards compatibility for scripts running mke2fs and tune2fs.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Provide mke2fs with a much more sophisticated system for controlling
configuration parameters of a newly created filesystem based on a
split filesystem and usage type system. The -t option to mke2fs was a
deprecated alias to -c; it now specifies a filesystem type (ext2,
ext3, ext4, etc.), while the -T option can now be a comma separated
usage list.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Theodore Ts'o