Author: Zdenek Kabelac <zkabelac(a)redhat.com>
AuthorDate: Wed Jan 23 22:51:00 2019 +0100
Committer: Zdenek Kabelac <zkabelac(a)redhat.com>
CommitterDate: Wed Mar 20 14:39:11 2019 +0100
man: dmeventd vdo plugin
man/dmeventd.8_main | 39 +++++++++++++++++++++++++++++++++++++--
1 files changed, 37 insertions(+), 2 deletions(-)
diff --git a/man/dmeventd.8_main b/man/dmeventd.8_main
index 06f8f58..dc4abf6 100644
@@ -125,6 +125,36 @@ To see the fullness of a thin pool command may check these
two environmental variables
\fBDMEVENTD_THIN_POOL_DATA\fP and \fBDMEVENTD_THIN_POOL_METADATA\fP.
Command can also read status with tools like \fBlvs\fP(8).
+Monitors how full a VDO pool data is becoming and emits
+a warning to syslog when it exceeds 80% full.
+The warning is repeated when more then 85%, 90% and 95%
+of the VDO pool is filled. See
+.BR lvm.conf (5).
+When a VDO pool fills over 50% vdo plugin calls
+configured \fIdmeventd/vdo_command\fP with every 5% increase.
+With default setting it calls internal
+\fBlvm lvextend --use-policies\fP to resize VDO pool
+when it's been filled above the configured threshold
+If the command fails, dmeventd vdo plugin will keep
+retrying execution with increasing time delay between
+retries upto 42 minutes.
+User may also configure external command to support more advanced
+maintenance operations of a VDO pool.
+Such external command can e.g. remove some unneeded space
+but also can use \fBlvextend --use-policies\fP if other actions
+have not released enough space.
+Command is executed with environmental variable
+\fBLVM_RUN_BY_DMEVENTD=1\fP so any lvm2 command executed
+in this environment will not try to interact with dmeventd.
+To see the fullness of a VDO pool command may check this
+environmental variable \fBDMEVENTD_VDO_POOL\fP.
+Command can also read status with tools like \fBlvs\fP(8).
.SH ENVIRONMENT VARIABLES
@@ -139,10 +169,15 @@ Variable is set by thin plugin and is available to executed program.
actual usage of thin pool metadata volume. Variable is not set when error event
+Variable is set by vdo plugin and is available to executed program. Value present
+actual usage of VDO pool data volume. Variable is not set when error event
-Variable is set by thin plugin to prohibit recursive interation
+Variable is set by thin and vdo plugin to prohibit recursive interation
with dmeventd by any executed lvm2 command from
-a thin_command environment.
+a thin_command, vdo_command environment.
.SH SEE ALSO