003 File Manager
Current Path:
/usr/src/lib/geom/journal
usr
/
src
/
lib
/
geom
/
journal
/
📁
..
📄
Makefile
(167 B)
📄
Makefile.depend
(333 B)
📄
geom_journal.c
(8.73 KB)
📄
geom_journal.h
(1.59 KB)
📄
geom_journal_ufs.c
(2.33 KB)
📄
gjournal.8
(9.71 KB)
Editing: gjournal.8
.\" Copyright (c) 2006-2009 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 February 17, 2009 .Dt GJOURNAL 8 .Os .Sh NAME .Nm gjournal .Nd "control utility for journaled devices" .Sh SYNOPSIS .Nm .Cm label .Op Fl cfhv .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 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 system is supported. .Pp To configure journaling on the UFS file system using .Nm , one should first create a .Nm provider using the .Nm utility, then run .Xr newfs 8 or .Xr tunefs 8 on it with the .Fl J flag which instructs UFS to cooperate with the .Nm provider below. There are important differences in how journaled 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 .Xr gmirror 8 or .Xr graid3 8 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 are 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 c Checksum journal records. .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 metadata. .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; recommended minimum is twice the size of the physical memory installed. It is not recommended to use .Nm for small file systems (e.g.: only few gigabytes big). .El .It Cm clear Clear metadata 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 journaling 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 && \e tunefs -J enable -n disable da0s1d.journal && \e mount -o async /dev/da0s1d.journal /mnt || \e mount /dev/da0s1d /mnt .Ed .Sh SYSCTLS Gjournal adds the sysctl level kern.geom.journal. The string and integer information available is detailed below. The changeable column shows whether a process with appropriate privilege may change the value. .Bl -column "accept_immediatelyXXXXXX" integerXXX -offset indent .It Sy "sysctl name Type Changeable" .It "debug integer yes" .It "switch_time integer yes" .It "force_switch integer yes" .It "parallel_flushes integer yes" .It "accept_immediately integer yes" .It "parallel_copies integer yes" .It "record_entries integer yes" .It "optimize integer yes" .El .Bl -tag -width 6n .It Li debug Setting a non-zero value enables debugging at various levels. Debug level 1 will record actions at a journal level, relating to journal switches, metadata updates, etc. Debug level 2 will record actions at a higher level, relating to the numbers of entries in journals, access requests, etc. Debug level 3 will record verbose detail, including insertion of I/Os to the journal. .It Li switch_time The maximum number of seconds a journal is allowed to remain open before switching to a new journal. .It Li force_switch Force a journal switch when the journal uses more than N% of the free journal space. .It Li parallel_flushes The number of flush I/O requests to be sent in parallel when flushing the journal to the data provider. .It Li accept_immediately The maximum number of I/O requests accepted at the same time. .It Li parallel_copies The number of copy I/O requests to send in parallel. .It Li record_entries The maximum number of record entries to allow in a single journal. .It Li optimize Controls whether entries in a journal will be optimized by combining overlapping I/Os into a single I/O and reordering the entries in a journal. This can be disabled by setting the sysctl to 0. .El .Ss cache The string and integer information available for the cache level is detailed below. The changeable column shows whether a process with appropriate privilege may change the value. .Bl -column "alloc_failuresXXXXXX" integerXXX -offset indent .It Sy "sysctl name Type Changeable" .It "used integer no" .It "limit integer yes" .It "divisor integer no" .It "switch integer yes" .It "misses integer yes" .It "alloc_failures integer yes" .El .Bl -tag -width 6n .It Li used The number of bytes currently allocated to the cache. .It Li limit The maximum number of bytes to be allocated to the cache. .It Li divisor Sets the cache size to be used as a proportion of kmem_size. A value of 2 (the default) will cause the cache size to be set to 1/2 of the kmem_size. .It Li switch Force a journal switch when this percentage of cache has been used. .It Li misses The number of cache misses, when data has been read, but was not found in the cache. .It Li alloc_failures The number of times memory failed to be allocated to the cache because the cache limit was hit. .El .Ss stats The string and integer information available for the statistics level is detailed below. The changeable column shows whether a process with appropriate privilege may change the value. .Bl -column "skipped_bytesXXXXXX" integerXXX -offset indent .It Sy "sysctl name Type Changeable" .It "skipped_bytes integer yes" .It "combined_ios integer yes" .It "switches integer yes" .It "wait_for_copy integer yes" .It "journal_full integer yes" .It "low_mem integer yes" .El .Bl -tag -width 6n .It Li skipped_bytes The number of bytes skipped. .It Li combined_ios The number of I/Os which were combined by journal optimization. .It Li switches The number of journal switches. .It Li wait_for_copy The number of times the journal switch process had to wait for the previous journal copy to complete. .It Li journal_full The number of times the journal was almost full, forcing a journal switch. .It Li low_mem The number of times the low_mem hook was called. .El .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 Mt pjd@FreeBSD.org
Upload File
Create Folder