Document soft updates journaling and GEOM-based UFS journaling.
Reviewed by: mckusick
This commit is contained in:
hrs
parent
b1c01808cb
commit
71e68b7fe7
@ -30,7 +30,7 @@
|
||||
.\"
|
||||
.\" $FreeBSD$
|
||||
.\"
|
||||
.Dd December 26, 2001
|
||||
.Dd August 25, 2019
|
||||
.Dt FFS 7
|
||||
.Os
|
||||
.Sh NAME
|
||||
@ -46,6 +46,7 @@ In the kernel configuration file:
|
||||
.Cd "options UFS_DIRHASH"
|
||||
.Cd "options UFS_EXTATTR"
|
||||
.Cd "options UFS_EXTATTR_AUTOSTART"
|
||||
.Cd "options UFS_GJOURNAL"
|
||||
.Pp
|
||||
In
|
||||
.Xr fstab 5 :
|
||||
@ -84,20 +85,65 @@ and enforces metadata update dependencies
|
||||
(e.g., updating free block maps)
|
||||
to ensure that the file system remains consistent.
|
||||
.Pp
|
||||
To enable soft updates on an
|
||||
.Em unmounted
|
||||
file system, use the following command:
|
||||
To create a new file system with the soft updates
|
||||
enabled,
|
||||
use
|
||||
.Xr newfs 8
|
||||
command:
|
||||
.Pp
|
||||
.D1 Nm tunefs Fl n Cm enable Ar fs
|
||||
.D1 Nm newfs Fl U Ar fs
|
||||
.Pp
|
||||
.Ar fs
|
||||
can be either a mount point listed in
|
||||
.Xr fstab 5
|
||||
(e.g.,
|
||||
.Pa /usr ) ,
|
||||
.Pq e.g. , Pa /usr ,
|
||||
or a disk device
|
||||
(e.g.,
|
||||
.Pa /dev/da0a ) .
|
||||
.Pq e.g., Pa /dev/da0a .
|
||||
.Pp
|
||||
It is possible to enable soft updates on an
|
||||
.Em unmounted
|
||||
file system by using
|
||||
.Xr tunefs 8
|
||||
command:
|
||||
.Pp
|
||||
.D1 Nm tunefs Fl n Cm enable Ar fs
|
||||
.Pp
|
||||
Soft updates can also add journaling that reduces the time spent by
|
||||
.Xr fsck_ffs 8
|
||||
cleaning up a filesystem after a crash from several minutes to a few seconds.
|
||||
The journal is placed in an inode named
|
||||
.Pa .sujournal ,
|
||||
and is kept as a circular log of segments containing
|
||||
records that describe metadata operations.
|
||||
.Pp
|
||||
To create a new file system with both the soft updates
|
||||
and soft updates journaling enabled,
|
||||
use the following command:
|
||||
.Pp
|
||||
.D1 Nm newfs Fl j Ar fs
|
||||
.Pp
|
||||
This runs
|
||||
.Xr tunefs 8
|
||||
command after
|
||||
.Xr newfs 8
|
||||
command with
|
||||
.Fl U
|
||||
flag enabled.
|
||||
It is possible to enable soft updates journaling on an
|
||||
.Em unmounted
|
||||
file system by using
|
||||
.Xr tunefs 8
|
||||
command:
|
||||
.Pp
|
||||
.D1 Nm tunefs Fl j Cm enable Ar fs
|
||||
.Pp
|
||||
This flag automatically enables the soft updates feature
|
||||
when it is not enabled.
|
||||
Note that this
|
||||
.Xr tunefs 8
|
||||
command will fail if a file
|
||||
.Pa .sujournal
|
||||
already exists before enabling the soft updates journaling.
|
||||
.El
|
||||
.Ss File Ownership Inheritance
|
||||
.Bl -tag -width 2n
|
||||
@ -155,10 +201,9 @@ extattrctl initattr -p / 388 posix1e.acl_default
|
||||
.Ed
|
||||
.Pp
|
||||
On the next mount of the root file system,
|
||||
the attributes will be automatically started
|
||||
(if
|
||||
the attributes will be automatically started if
|
||||
.Dv UFS_EXTATTR_AUTOSTART
|
||||
is included in the kernel configuration),
|
||||
is included in the kernel configuration,
|
||||
and ACLs will be enabled.
|
||||
.Ss Directory Hashing
|
||||
.Bl -tag -width 2n
|
||||
@ -183,7 +228,52 @@ subdirectory of the file system root during the mount operation.
|
||||
If found, extended attribute support will be
|
||||
automatically started for that file system.
|
||||
.El
|
||||
.Ss GEOM-based Journaling
|
||||
.Bl -tag -width 2n
|
||||
.It Cd "options UFS_GJOURNAL"
|
||||
Implements a block level journaling of a UFS file system,
|
||||
which is for both data and metadata.
|
||||
To enable this,
|
||||
create a
|
||||
.Xr gjournal 8
|
||||
GEOM provider for a block device by using the
|
||||
following command:
|
||||
.Pp
|
||||
.D1 Nm gjournal label Ar da0
|
||||
.Pp
|
||||
In this example,
|
||||
.Pa /dev/da0
|
||||
is used as the target block device,
|
||||
and
|
||||
.Pa /dev/da0.journal
|
||||
is created.
|
||||
Then create a new file system by using
|
||||
.Xr newfs 8
|
||||
with the block level journaling flag and mount it:
|
||||
.Pp
|
||||
.D1 Nm newfs Fl J Ar /dev/da0.journal
|
||||
.D1 Nm mount Fl o Cm async Ar /dev/da0.journal Ar /mnt
|
||||
.Pp
|
||||
.Cm async
|
||||
option is not mandatory but recommended for better performance
|
||||
because the journaling guarantees the consistency of an
|
||||
.Cm async
|
||||
mount.
|
||||
.Pp
|
||||
It is also possible to enable the block level journaling
|
||||
on an existing file system.
|
||||
To do so,
|
||||
use
|
||||
.Xr gjournal 8
|
||||
utility to label the underlying block device and
|
||||
.Xr tunefs 8
|
||||
utility to enable the block level journaling flag:
|
||||
.Pp
|
||||
.D1 Nm gjournal label Ar da0
|
||||
.D1 Nm tunefs Fl J Cm enable Ar /dev/da0.journal
|
||||
.D1 Nm mount Fl o Cm async Ar /dev/da0.journal Ar /mnt
|
||||
.El
|
||||
.Ss Xr sysctl 8 MIBs
|
||||
The following
|
||||
.Xr sysctl 8
|
||||
MIBs are defined for use with
|
||||
@ -192,11 +282,11 @@ MIBs are defined for use with
|
||||
.It Va vfs.ffs.doasyncfree
|
||||
Asynchronously write out modified i-node and indirect blocks
|
||||
upon reallocating file system blocks to be contiguous.
|
||||
(Default: 1.)
|
||||
.Pq Default: 1 .
|
||||
.It Va vfs.ffs.doreallocblks
|
||||
Enable support for the rearrangement of blocks
|
||||
to be contiguous.
|
||||
(Default: 1.)
|
||||
.Pq Default: 1 .
|
||||
.El
|
||||
.Sh SEE ALSO
|
||||
.Xr quota 1 ,
|
||||
@ -204,7 +294,9 @@ to be contiguous.
|
||||
.Xr extattr 3 ,
|
||||
.Xr edquota 8 ,
|
||||
.Xr extattrctl 8 ,
|
||||
.Xr sysctl 8
|
||||
.Xr fsck_ffs 8 ,
|
||||
.Xr sysctl 8 ,
|
||||
.Xr tunefs 8
|
||||
.Rs
|
||||
.%A M. McKusick
|
||||
.%A W. Joy
|
||||
@ -224,3 +316,10 @@ to be contiguous.
|
||||
.%J "Proceedings of the Freenix Track at the 1999 Usenix Annual Technical Conference"
|
||||
.%P 71-84
|
||||
.Re
|
||||
.Rs
|
||||
.%A M. McKusick
|
||||
.%A J. Roberson
|
||||
.%D May 2010
|
||||
.%T "Journaled Soft-updates"
|
||||
.%J "BSD Canada Conference 2010 (BSDCan)"
|
||||
.Re
|
||||
|
||||
Loading…
Reference in New Issue
Block a user