|Distribution:||official part of Check_MK|
|Supported Agents:||Linux, FREEBSD|
This check measures the throughput of block devices (disks) on Linux
hosts. You can either have a single check for every single disk
or a summary check (which is the default) summing up the throughput
of all disks.
For legacy reasons it is also possible (but not advisable) to have all disks
summarized but with a separate check for read and write (this is how this
check worked up to version 1.1.10).
The check also gives info on the IO latency and IOPS (unmerged) aquired
from the kernels information in /proc.
You can apply separate warning and critical levels for the read
and write throughput. Optionally you can have the check compute
average values on a configurable time period and have the levels
applied on the average instead of the current values. This makes
it possible to ignore short "peaks" and only trigger and longer
phases of high disk activity.
Averaging is not applied to IO latency calculations.
The check has to provide many ways of configuration for legacy reasons.
We strongly recommend you switch to the rule-based configuration, which
handles anything you want it to.
In single disk mode the check now also supports being used in a Check_MK
cluster environment. In this case it goes to CRIT if it finds more than
one disk item in the cluster. If it finds only one disk item, it also prints
the node name the disk was found on.
SUMMARY and legacy read/write modes are not supported in a cluster
configuration. The check goes to UNKNOWN and prints an appropriate message
if configured like that.
Either "SUMMARY" for a summarized check of all disks or the name of the
disk device, e.g. "sda". Additionally also one service per logical volume
defined in Linux LVM and Veritas VxVM on Linux.
In order to support configurations
up to version 1.1.10 also the items "read" and "write" are supported.
The inventory is configured via diskstat_inventory_mode. If this is set
to "single" (the default), then one check will be created for each
disk. If it is set to "summary" then only one service per host will be
created that has at least one hard disk. If set to "legacy" then a
separate check for read and write will be created (deprecated).