I’ve been told that I can only verify my HW RAID array is working perfectly with KVM. However, I want to be automatically notified when there is a problem by my server.
Is there a way via SSH (that will be called via system() in php) that can detect that a drive is having problems? I don’t need to identify which drive.
I have thought of one theory but I don’t know if it will work in practice. If I were to run a PHP script to fopen(‘/dev/[filesystem]’, ‘r’) and seeked every xGB for 1 byte and it seeks a position of the filesystem that’s having problems, it should return an error. Am I correct in thinking this idea?
I use XFS filesystem, I have heard of xfs_check but that says it needs to be ran in read-only mode which is inconvenient.
I use 3ware RAID controller.
Answer
Install the 3Ware tools (tw_cli) on your machine.
After you have installed them, get the id # of the controller (I’ve never understood the system behind it, for all I know it might be random):
$ tw_cli show
Ctl Model (V)Ports Drives Units NotOpt RRate VRate BBU
------------------------------------------------------------------------
c0 9550SXU-4LP 4 2 1 0 1 1 -
You can then query the array status with
$ tw_cli /c0 show
Unit UnitType Status %RCmpl %V/I/M Stripe Size(GB) Cache AVrfy
------------------------------------------------------------------------------
u0 RAID-1 OK - - - 74.4951 ON OFF
Port Status Unit Size Blocks Serial
---------------------------------------------------------------
p0 NOT-PRESENT - - - -
p1 NOT-PRESENT - - - -
p2 OK u0 74.53 GB 156301488 9QZ07NP2
p3 OK u0 74.53 GB 156301488 9QZ08DS2
Obviously, this will look different on your machine. These example where lifted from here.
To actively verify (scrub) your drives, use
$ tw_cli /c0/u0 start verify
For automatic notifications, you should setup a monitoring system, e.g. Nagios or Icinga and use a plugin that checks the health of the array with the help of tw_cli. These plugins work nicely without Nagios/Icinga as well and could be easily used in a minimal monitoring system in form of a cron job that sends a mail of the plugin doesn’t return 0.
Attribution
Source : Link , Question Author : user3786834 , Answer Author : Sven
