mdmfs(8) lacks the ability to populate throwaway memory filesystems from an
existing directory.
This features permits an interesting setup where /var for instance lives on
a device where wear-leveling is something you want to avoid as much as
possible and nonetheless you don't want to lose your logs, ports metadata,
etc. Here are the steps:
1. Copy /var to /var.bak;
2. Mount an mfs into /var using -k /var.bak at startup;
3. Synchronize /var to /var.bak weekly and on shutdown.
Note that this more or less mimics OpenBSD's mount_mfs(8) -P flag.
PR: 146254
Submitted by: jlh (many moons ago)
MFC after: 1 week
Existing scripts and associated config such as rc.initdiskless, rc.d/var,
and others, use mdmfs to create memory filesystems. That program accepts a
size argument which allows SI suffixes and treats an unsuffixed number as a
count of 512 byte sectors. That makes it difficult to convert existing
scripts to use tmpfs instead of mdmfs, because tmpfs treats unsuffixed
numbers as a count of bytes. The script logic to deal with existing user
config that might include suffixed and unsuffixed numbers is... unpleasant.
Also, there is no g'tee that tmpfs will be available. It is sometimes
configured out of small-resource embedded systems to save memory and flash
storage space.
These changes enhance mdmfs(8) so that it accepts two new values for the
'md-device' arg: 'tmpfs' and 'auto'. With tmpfs, the program always uses
tmpfs(5) (and fails if it's not available). With 'auto' the program prefers
tmpfs, but falls back to using md(4) if tmpfs isn't available. It also
handles the -s <size> argument so that the mdconfig interpetation of
unsuffixed numbers applies when tmpfs is used as well, so that existing user
config keeps working after a switch to tmpfs.
A new rc setting, mfs_type, is added to etc/defaults/rc.conf to let users
force the use of tmpfs or md; the default value is "auto".
Differential Revision: https://reviews.freebsd.org/D12301
gmultipath.8: Add HISTORY
Adjust sentences with bad phrases picked up by igor
ggatec.8: Add HISTORY
ggated.8: Add HISTORY
ggatel.8: Add HISTORY
Seperate out sentence as advised by igor.
hastctl.8: Add HISTORY
hastd.8: Add HISTORY
Fix sentence highlighted by igor.
iscontrol.8: Add HISTORY
mdmfs.8: Add HISTORY
Address issues raised by igor
mount_nfs.8: Add HISTORY
Not sure where mount_nfs first showed up, but the verison used
in the BSD's originates from 4.4BSD according to CSRG archive.
Though commercial offerings from Sun and others covers older
systems, eg https://groups.google.com/forum/#!topic/net.unix-wizards/lMe7aQikqJI
nandfs.8: Add HISTORY
Adjust sentence in description to address bad phrase highlighted
by igor.
nvmecontrol.8: Add HISTORY
PR: 212491
PR: 212498
PR: 212499
PR: 212500
PR: 212501
PR: 212502
PR: 212505
PR: 212508
PR: 212540
PR: 212543
PR: 212546
Submitted by: Sevan Janiyan <venture37@geeklan.co.uk>
compatible, it would have to (at least):
- support the "compat-compat" -T option,
- *not* support the -l, -O, and -v options,
- default to soft updates being disabled.
Worse, the compatibility mode makes it impossible to mount_mfs(8)
a file system from fstab(5) with soft updates disabled (-S). [1]
Now, the only difference when called as "mount_mfs" or "mfs" (as
opposed to "mdmfs") is that the file mode of the mount point is
set by default to 01777. All options available to mdmfs(8) are
also available to mount_mfs(8); the -C option is still recognized
but ignored for backward compatibility.
PR: bin/98860 [1]
MFC after: 2 weeks
disk. Apparently some people want to use mdmfs as mount_* as a
shortcut for mounting existing file-based file systems.
Note that unlike in the patches from the submitters, this option is
not available in compat mode. Compat mode was supposed to support only
things that mount_mfs used to support. To use this option from fstab,
mdmfs should be called mount_md, not mount_mfs. This distinction has
not always upkept for new options, and those can't be fixed now
without breaking people's systems, but new options should not usually
be allowed in compat mode. (Not sure why -F is allowed there at all.)
PR: 57641
Submitted by: Ruben de Groot
Submitted independently by: Wojciech A. Koszek, for Urzad Miasta Czestochowa
created with the multilabel flag from inception. This simply
passes the "-l" flag on to newfs(8).
Obtained from: TrustedBSD Project
Sponsored by: DARPA, McAfee Research
of an argument name collision with -O, use -v, and default to whatever
the newfs default is for the platform (generally, UFS1). This is
required to support diskless workstations that use UFS2 for their
mdmfs file systems.
Reviewed by: dd, bmah
Approved by: re (bmah)
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
name is "mount_mfs" or "mfs". Previously, the condition was that
the program name must start with "mount_", but this both missed
the case where mount(8) invokes mdmfs with argv[0] = "mfs", and it
included cases such as "mount_md" where compatibility is not
required.
Reviewed by: dd
default if the executable is named (called as) "mount_*", or can be
enabled with the -C option. This allows users to leave their old
fstab entires unchanged (modulo symlink'ing mdmfs to mount(md|mfs))
and have things behave the way they should (by emulating mount_mfs
silliness), while still allowing mdmfs to be used as a generic
make-an-md-and-mount-it type thing.
Right now, the only effects of this option is to set the mount-point
mode to 01777 as if "-p 1777" was given, and to complain about getting
command-line options that mount_mfs didn't take (e.g., -X, -L, et al).
The latter is mostly to try to catch operator errors.
Also implement -U, which turns on soft-updates. It's redundant (since
softdep is the default), but implement it anyway for compatibility.
