Select partitions based on the filesystem type.
-=item B<IgnoreSelected> I<true>|I<false>
+=item B<IgnoreSelected> B<true>|B<false>
Invert the selection: If set to true, all partitions B<except> the ones that
match any one of the criteria are collected. By default only selected
partitions are collected if a selection is made. If no selection is configured
at all, B<all> partitions are selected.
-=item B<ReportByDevice> I<true>|I<false>
+=item B<ReportByDevice> B<true>|B<false>
Report using the device name rather than the mountpoint. i.e. with this I<false>,
(the default), it will report a disk as "root", but with it I<true>, it will be
"sda1" (or whichever).
+=item B<ReportReserved> B<true>|B<false>
+
+When enabled, the blocks reserved for root are reported separately. When
+disabled (the default for backwards compatibility reasons) the reserved space
+will be included in the "free" space.
+
+When disabled, the "df" type will be used to store "free" and "used" space. The
+mount point or disk name (see option B<ReportByDevice>) is used as type
+instance in this case (again: backwards compatibility).
+
+When enabled, the type "df_complex" is used and three files are created. The
+mount point or disk name is used as plugin instance and the type instance is
+set to "free", "reserved" and "used" as appropriate.
+
+Enabling this option is recommended.
+
+=item B<ReportInodes> B<true>|B<false>
+
+Enables or disables reporting of free, reserved and used inodes. Defaults to
+inode collection being disabled.
+
+Enable this option if inodes are a scarce resource for you, usually because
+many small files are stored on the disk. This is a usual scenario for mail
+transfer agents and web caches.
+
=back
=head2 Plugin C<disk>
GetBusy true
</Disks>
- <GetVolumePerfData>
- </GetVolumePerfData>
+ <VolumePerf>
+ Interval 30
+ GetIO "volume0"
+ IgnoreSelectedIO false
+ GetOps "volume0"
+ IgnoreSelectedOps false
+ GetLatency "volume0"
+ IgnoreSelectedLatency false
+ </VolumePerf>
<VolumeUsage>
- Capacity "vol0"
- Capacity "vol1"
+ Interval 30
+ GetCapacity "vol0"
+ GetCapacity "vol1"
IgnoreSelectedCapacity false
- Snapshot "vol1"
- Snapshot "vol3"
+ GetSnapshot "vol1"
+ GetSnapshot "vol3"
IgnoreSelectedSnapshot false
</VolumeUsage>
=over 4
-=item B<Multiplier> I<Multiplier>
-
-The host specific interval between data collections is multiplied by this value
-for collecting these data.
-
-Optional
-
-Type: integer
+=item B<Interval> I<Seconds>
-Default: 1
+Collect the respective statistics every I<Seconds> seconds. Defaults to the
+host specific setting.
=back
=back
-=head3 The GetVolumePerfData block
+=head3 The VolumePerf block
This will collect various performance data about the individual volumes.
-All of these options take a list of volumes as parameters. In this case
-"volume" means just the name of the volume, without the "/vol/" prefix or
-anything like that.
-
-The special values "-" and "+" are supported. "-" means "don't collect values
-for any volumes". "+" means "collect values for all volumes, even volumes that
-are created after collectd was started." Additionally you can prefix a volume
-name with a "-" sign to exclude this one volume. Eg '"+" "-vol0"' collectes
-values for all volumes except vol0. The order of the parameters is important.
-'"-vol0" "+"' doesn't make sense because the "+" overrides the earlier "-vol0".
+You can select which data to collect about which volume using the following
+options. They follow the standard ignorelist semantic.
B<Note:> To get this data the collectd user needs the
-"api-perf-object-get-instances" capability.
+I<api-perf-object-get-instances> capability.
=over 4
-=item B<GetIO> I<Volume> [I<Volume> ...]
-The current IO throughput will be read for every volume specified here.
+=item B<Interval> I<Seconds>
-Optional
+Collect volume performance data every I<Seconds> seconds.
-Type: list of strings
+=item B<GetIO> I<Volume>
-Default: "+"
+=item B<GetOps> I<Volume>
-Result: Data sources of type "disk_octets" and the name of the volume as
-plugin_instance.
+=item B<GetLatency> I<Volume>
-=item B<GetOps> I<Volume> [I<Volume> ...]
+Select the given volume for IO, operations or latency statistics collection.
+The argument is the name of the volume without the C</vol/> prefix.
-The current number of operation will be read for every volume specified here.
+Since the standard ignorelist functionality is used here, you can use a string
+starting and ending with a slash to specify regular expression matching: To
+match the volumes "vol0", "vol2" and "vol7", you can use this regular
+expression:
-Optional
+ GetIO "/^vol[027]$/"
-Type: list of strings
+If no regular expression is specified, an exact match is required. Both,
+regular and exact matching are case sensitive.
-Default: "+"
+If no volume was specified at all for either of the three options, that data
+will be collected for all available volumes.
-Result: Data sources of type "disk_ops" and the name of the volume as
-plugin_instance.
+=item B<IgnoreSelectedIO> B<true>|B<false>
-=item B<GetLatency> I<Volume> [I<Volume> ...]
+=item B<IgnoreSelectedOps> B<true>|B<false>
-The current latency for volume access in microseconds will be read for every
-volume specified here.
+=item B<IgnoreSelectedLatency> B<true>|B<false>
-Optional
+When set to B<true>, the volumes selected for IO, operations or latency
+statistics collection will be ignored and the data will be collected for all
+other volumes.
-Type: list of strings
+When set to B<false>, data will only be collected for the specified volumes and
+all other volumes will be ignored.
-Default: "+"
+If no volumes have been specified with the above B<Get*> options, all volumes
+will be collected regardless of the B<IgnoreSelected*> option.
-Result: Data sources of type "disk_latency" and the name of the volume as
-plugin_instance.
+Defaults to B<false>
=back
=over 4
-=item B<Capacity> I<VolumeName>
+=item B<Interval> I<Seconds>
+
+Collect volume usage statistics every I<Seconds> seconds.
+
+=item B<GetCapacity> I<VolumeName>
The current capacity of the volume will be collected. This will result in two
to four value lists, depending on the configuration of the volume. All data
=item B<IgnoreSelectedCapacity> B<true>|B<false>
-Specify whether to collect only the volumes selected by the B<Capacity> option
-or to ignore those volumes. B<IgnoreSelectedCapacity> defaults to B<false>.
-However, if no B<Capacity> option is specified at all, all capacities will be
-selected anyway.
+Specify whether to collect only the volumes selected by the B<GetCapacity>
+option or to ignore those volumes. B<IgnoreSelectedCapacity> defaults to
+B<false>. However, if no B<GetCapacity> option is specified at all, all
+capacities will be selected anyway.
+
+=item B<GetSnapshot> I<VolumeName>
-=item B<Snapshot> I<VolumeName>
+Select volumes from which to collect snapshot information.
-B<Defunct!> Select volumes from which to collect snapshot information.
+Usually, the space used for snapshots is included in the space reported as
+"used". If snapshot information is collected as well, the space used for
+snapshots is subtracted from the used space.
+
+To make things even more interesting, it is possible to reserve space to be
+used for snapshots. If the space required for snapshots is less than that
+reserved space, there is "reserved free" and "reserved used" space in addition
+to "free" and "used". If the space required for snapshots exceeds the reserved
+space, that part allocated in the normal space is subtracted from the "used"
+space again.
Repeat this option to specify multiple volumes.
=item B<IgnoreSelectedSnapshot>
-Specify whether to collect only the volumes selected by the B<Snapshot> option
-or to ignore those volumes. B<IgnoreSelectedSnapshot> defaults to B<false>.
-However, if no B<Snapshot> option is specified at all, all capacities will be
-selected anyway.
+Specify whether to collect only the volumes selected by the B<GetSnapshot>
+option or to ignore those volumes. B<IgnoreSelectedSnapshot> defaults to
+B<false>. However, if no B<GetSnapshot> option is specified at all, all
+capacities will be selected anyway.
=back
usually), the graph will be empty (NAN) for a long time. People may not
understand why.
+=item B<hashed>
+
+Calculates a hash value of the host name and matches values according to that
+hash value. This makes it possible to divide all hosts into groups and match
+only values that are in a specific group. The intended use is in load
+balancing, where you want to handle only part of all data and leave the rest
+for other servers.
+
+The hashing function used tries to distribute the hosts evenly. First, it
+calculates a 32E<nbsp>bit hash value using the characters of the hostname:
+
+ hash_value = 0;
+ for (i = 0; host[i] != 0; i++)
+ hash_value = (hash_value * 251) + host[i];
+
+The constant 251 is a prime number which is supposed to make this hash value
+more random. The code then checks the group for this host according to the
+I<Total> and I<Match> arguments:
+
+ if ((hash_value % Total) == Match)
+ matches;
+ else
+ does not match;
+
+Please note that when you set I<Total> to two (i.E<nbsp>e. you have only two
+groups), then the least significant bit of the hash value will be the XOR of
+all least significant bits in the host name. One consequence is that when you
+have two hosts, "server0.example.com" and "server1.example.com", where the host
+name differs in one digit only and the digits differ by one, those hosts will
+never end up in the same group.
+
+Available options:
+
+=over 4
+
+=item B<Match> I<Match> I<Total>
+
+Divide the data into I<Total> groups and match all hosts in group I<Match> as
+described above. The groups are numbered from zero, i.E<nbsp>e. I<Match> must
+be smaller than I<Total>. I<Total> must be at least one, although only values
+greater than one really do make any sense.
+
+You can repeat this option to match multiple groups, for example:
+
+ Match 3 7
+ Match 5 7
+
+The above config will divide the data into seven groups and match groups three
+and five. One use would be to keep every value on two hosts so that if one
+fails the missing data can later be reconstructed from the second host.
+
+=back
+
+Example:
+
+ # Operate on the pre-cache chain, so that ignored values are not even in the
+ # global cache.
+ <Chain "PreCache">
+ <Rule>
+ <Match "hashed">
+ # Divide all received hosts in seven groups and accept all hosts in
+ # group three.
+ Match 3 7
+ </Match>
+ # If matched: Return and continue.
+ Target "return"
+ </Rule>
+ # If not matched: Return and stop.
+ Target "stop"
+ </Chain>
+
=back
=head2 Available targets
projects / collectd.git / blobdiff