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author | pjd <pjd@FreeBSD.org> | 2007-01-29 22:12:22 +0000 |
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committer | pjd <pjd@FreeBSD.org> | 2007-01-29 22:12:22 +0000 |
commit | 1fff60d4b20349a0d5bdf918aab88061a054c7e6 (patch) | |
tree | 665ea2562899f6825317709211504218d6d47a26 /sbin/geom | |
parent | 165b7b2e7f95b31e4f0ff641c16f77f0e60af46e (diff) | |
download | FreeBSD-src-1fff60d4b20349a0d5bdf918aab88061a054c7e6.zip FreeBSD-src-1fff60d4b20349a0d5bdf918aab88061a054c7e6.tar.gz |
Add gjournal(8) manual page. Documentation of kern.geom.journal.* sysctls
is still missing, ehh.
Reviewed by: trhodes
Diffstat (limited to 'sbin/geom')
-rw-r--r-- | sbin/geom/class/journal/gjournal.8 | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/sbin/geom/class/journal/gjournal.8 b/sbin/geom/class/journal/gjournal.8 new file mode 100644 index 0000000..a07119b --- /dev/null +++ b/sbin/geom/class/journal/gjournal.8 @@ -0,0 +1,238 @@ +.\" Copyright (c) 2006-2007 Pawel Jakub Dawidek <pjd@FreeBSD.org> +.\" All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" $FreeBSD$ +.\" +.Dd December 5, 2006 +.Dt GJOURNAL 8 +.Os +.Sh NAME +.Nm gjournal +.Nd "control utility for journaled devices" +.Sh SYNOPSIS +.Nm +.Cm label +.Op Fl fhv +.Op Fl s Ar jsize +.Ar dataprov +.Op Ar jprov +.Nm +.Cm stop +.Op Fl fv +.Ar name ... +.Nm +.Cm sync +.Op Fl v +.Nm +.Cm clear +.Op Fl v +.Ar prov ... +.Nm +.Cm dump +.Ar prov ... +.Nm +.Cm list +.Nm +.Cm status +.Nm +.Cm load +.Nm +.Cm unload +.Sh DESCRIPTION +The +.Nm +utility is used for journal configuration on the given GEOM provider. +The Journal and data may be stored on the same provider or on two separate +providers. +This is block level journaling, not file system level journaling, which means +.Nm +everything gets logged, e.g.: for file systems, it journals both data and +metadata. +The +.Nm +GEOM class can talk to file systems, which allows the use of +.Nm +for file system journaling and to keep file systems in a consistent state. +At this time, only UFS file systems are supported. +.Pp +.\" XXX This next sentence needs fixed, it's a run on. +To configure journaling via +.Nm +for the UFS file system, one should create a gjournaled provider using the +.Nm +utility with the +.Fl J +flag for +.Xr newfs 8 +or +.Xr tunefs 8 +which instructs UFS to cooperate with the +.Nm +provider below. +There are important differences in how gjournaled UFS works. +The most important one is that +.Xr sync 2 +and +.Xr fsync 2 +system calls do not work as expected anymore. +To ensure that data is stored on the data provider, the +.Nm Cm sync +command should be used after calling +.Xr sync 2 . +For the best performance possible, soft-updates should be disabled when +.Nm +is used. +It is also safe and recommended to use the +.Cm async +.Xr mount 8 +option. +.Pp +When +.Nm +is configured on top of +.Nm gmirror +or +.Nm graid3 +providers, it also keeps them in a consistent state, thus +automatic synchronization on power failure or system crash may be disabled +on those providers. +.Pp +The +.Nm +utility uses on-disk metadata, stored in the provider's last sector, to store all needed +information. +This could be a problem when an existing file system is converted to use +.Nm . +.Pp +The first argument to +.Nm +indicates an action to be performed: +.Bl -tag -width ".Cm status" +.It Cm label +Configures +.Nm +on the given provider(s). +If only one provider is given, both data and journal is stored on the same +provider. +If two providers are given, the first one will be used as data provider and the +second will be used as the journal provider. +.Pp +Additional options include: +.Bl -tag -width ".Fl s Ar jsize" +.It Fl f +May be used to convert an existing file system to use +.Nm , +but only if the journal will be configured on a separate provider and if the last +sector in the data provider is not used by the existing file system. +If +.Nm +detects that the last sector is used, it will refuse to overwrite it +and return an error. +This behavior may be forced by using the +.Fl f +flag, which will force +.Nm +to overwrite the last sector. +.It Fl h +Hardcode provider names in meta-data. +.It Fl s Ar jsize +Specifies size of the journal if only one provider is used for both data and +journal. +The default is one gigabyte. +Size should be chosen based on provider's load, and not on its size. +It is not recommended to use +.Nm +for small file systems (e.g.: only few gigabytes big). +.El +.It Cm clear +Clear meta-data on the given providers. +.It Cm stop +Stop the given provider. +.Pp +Additional options include: +.Bl -tag -width ".Fl f" +.It Fl f +Stop the given provider even if it is opened. +.El +.It Cm sync +Trigger journal switch and enforce sending data to the data provider. +.It Cm dump +Dump metadata stored on the given providers. +.It Cm list +See +.Xr geom 8 . +.It Cm status +See +.Xr geom 8 . +.It Cm load +See +.Xr geom 8 . +.It Cm unload +See +.Xr geom 8 . +.El +.Pp +Additional options include: +.Bl -tag -width ".Fl v" +.It Fl v +Be more verbose. +.El +.Sh EXIT STATUS +Exit status is 0 on success, and 1 if the command fails. +.Sh EXAMPLES +Create a +.Nm +based UFS file system and mount it: +.Bd -literal -offset indent +gjournal load +gjournal label da0 +newfs -J /dev/da0.journal +mount -o async /dev/da0.journal /mnt +.Ed +.Pp +Configure gjournaling on an existing file system, but only if +.Nm +allows this (i.e.: if the last sector is not already used by the file system): +.Bd -literal -offset indent +umount /dev/da0s1d +gjournal label da0s1d da0s1e && tunefs -J enable -n disable && mount -o async /dev/da0s1d.journal /mnt || mount /dev/da0s1d /mnt +.Ed +.Sh SEE ALSO +.Xr geom 4 , +.Xr geom 8 , +.Xr mount 8 , +.Xr newfs 8 , +.Xr tunefs 8 , +.Xr umount 8 +.Sh HISTORY +The +.Nm +utility appeared in +.Fx 7.0 . +.Sh AUTHORS +.An Pawel Jakub Dawidek Aq pjd@FreeBSD.org +.Sh BUGS +Documentation for sysctls +.Va kern.geom.journal.* +is missing. |