UserParameter=custom.md.discovery do not parse raid0

[denisgolius]

So I have ubuntu 20.04 with raid0

 mdadm -D /dev/md0
/dev/md0:
           Version : 1.2
     Creation Time : Mon Sep 28 21:34:49 2020
        Raid Level : raid0
        Array Size : 7813520384 (7451.55 GiB 8001.04 GB)
      Raid Devices : 4
     Total Devices : 4
       Persistence : Superblock is persistent

       Update Time : Mon Sep 28 21:34:49 2020
             State : clean 
    Active Devices : 4
   Working Devices : 4
    Failed Devices : 0
     Spare Devices : 0

            Layout : original
        Chunk Size : 512K

Consistency Policy : none

              Name : ubuntu-server:0
              UUID : b14fa1a1:96da7eba:8fd8a81c:36258895
            Events : 0

    Number   Major   Minor   RaidDevice State
       0       8       34        0      active sync   /dev/sdc2
       1       8       17        1      active sync   /dev/sdb1
       2       8        1        2      active sync   /dev/sda1
       3       8       49        3      active sync   /dev/sdd1

I copied your userparameter_md.conf file into /etc/zabbix/zabbix_agentd.d folder . For the servers that have configured raid1 - this parameter works well:
UserParameter=custom.md.discovery,cat /proc/mdstat | grep -B 1 -E "(U+|_+)" | awk 'BEGIN { printf "{\"data\":["}; /^md/ { printf c"{\"{#MDNAME}\":\""$1"\"}";c=","}; END{ print "]}" }'

But I have raid0 and this grep cat /proc/mdstat | grep -B 1 -E "(U+|_+)" not parsed it. It returned NULL, because it parse UU that is not used for raid0.
And if you try to use this user parameter:
UserParameter=custom.md.discovery,cat /proc/mdstat | awk 'BEGIN { printf "{\"data\":["}; /^md/ { printf c"{\"{#MDNAME}\":\""$1"\"}";c=","}; END{ print "]}" }' - zabbix will parse raid0 devices.

[paraenggu]

Hi @denisgolius,

where does the user parameter custom.md.discovery originates from?

The user parameters included in MD-RAID are using the sysfs interface and not /proc/mdstat for array discovery: UserParameter=rabe.raid.md.raid-device.discovery,/usr/bin/find -L /sys/block/ [...].