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author | David Teigland <teigland@redhat.com> | 2022-02-16 15:21:09 -0600 |
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committer | David Teigland <teigland@redhat.com> | 2022-02-16 15:21:09 -0600 |
commit | ec2119beddde9e38681cb096b93048ee25034c1e (patch) | |
tree | 1dd716ee31e6b006312e51a3297382e7cfb95481 /man | |
parent | d4a0816a5824dc375d662e76823ee8ed77bb9983 (diff) | |
download | lvm2-ec2119beddde9e38681cb096b93048ee25034c1e.tar.gz |
man lvmcache: add more writecache cachesettings info
Diffstat (limited to 'man')
-rw-r--r-- | man/lvmcache.7_main | 51 |
1 files changed, 39 insertions, 12 deletions
diff --git a/man/lvmcache.7_main b/man/lvmcache.7_main index 8d7d3d17b..dddd33cfa 100644 --- a/man/lvmcache.7_main +++ b/man/lvmcache.7_main @@ -243,15 +243,40 @@ can be used. . .SS dm-writecache settings . -Tunable parameters can be passed to the dm-writecache kernel module using -the --cachesettings option when caching is started, e.g. +To specify dm-writecache tunable settings on the command line, use: +.br +--cachesettings 'option=N' or +.br +--cachesettings 'option1=N option2=N ...' +.P +For example, --cachesettings 'high_watermark=90 writeback_jobs=4'. +.P +To include settings when caching is started, run: .P .nf # lvconvert --type writecache --cachevol fast \\ - --cachesettings 'high_watermark=N writeback_jobs=N' vg/main + --cachesettings 'option=N' vg/main +.fi +.P +To change settings for an existing writecache, run: +.P +.nf +# lvchange --cachesettings 'option=N' vg/main +.fi +.P +To clear all settings that have been applied, run: +.P +.nf +# lvchange --cachesettings '' vg/main +.fi +.P +To view the settings that are applied to a writecache LV, run: +.P +.nf +# lvs -o cachesettings vg/main .fi .P -Tunable options are: +Tunable settings are: . .TP high_watermark = <percent> @@ -301,11 +326,14 @@ writecache. Adding cleaner=0 to the splitcache command will skip the cleaner mode, and any required flushing is performed in device suspend. .SS dm-writecache using metadata profiles - -Writecache allows to set a variety of options. Lots of these settings -can be specified in lvm.conf or profile settings. You can prepare -a number of different profiles in the \fI#DEFAULT_SYS_DIR#/profile\fP directory -and just specify the metadata profile file name when writecaching LV. +. +In addition to specifying writecache settings on the command line, they +can also be set in lvm.conf, or in a profile file, using the +allocation/cache_settings/writecache config structure shown below. +.P +It's possible to prepare a number of different profile files in the +\fI#DEFAULT_SYS_DIR#/profile\fP directory and specify the file name +of the profile when starting writecache. .P .I Example .nf @@ -327,11 +355,10 @@ writeback_jobs=1024 EOF .P -# lvcreate -an -L10G --name wcache vg /dev/fast_ssd -# lvcreate --type writecache -L10G --name main --cachevol wcache \\ +# lvcreate -an -L10G --name fast vg /dev/fast_ssd +# lvcreate --type writecache -L10G --name main --cachevol fast \\ --metadataprofile cache_writecache vg /dev/slow_hdd .fi - . .SS dm-cache with separate data and metadata LVs . |