Check-RAID
This script was found on ServerFault.com after having asked about differences between hardware and software RAID Systems. One user, Gordon Davisson, added a nice contribution about silent failures of Apple's sofwtare RAIDs on Mac OS X. A bad point raised earlier in the comments.
Here is his answer:
I'll second SvenW's warning about silent failures; if anything, it's a little too good at surviving a drive failure. I've seen the aftermath of a couple of servers that had one drive drop out of a software mirror for some reason (I suspect not coming ready in time after a reboot); everything works fine off the remaining drive until, several months later, something goes wrong with THAT drive -- and it switches back to the drive that glitched the first time, and the last few months have vanished.
Here's a short shell script I whipped up to fix this. Substitute in your email address, save it as something like /etc/periodic/daily/150.check-raid, make it executable, and it should mail you a warning (at 3:15 the next morning) if the raid ever degrades. To test it (strongly recommended in case of spam blocks, etc), plug in a couple of disposable drives (USB keychain drives, whatever), mirror them, unplug one, leave the other overnight and see if you have a warning in your mailbox in the morning.
The code
The code was copied from Gordon's answer and few adjustments were made.
Credits
Credits goes to Gordon Davisson for the original script.
Compatibility
Mac OS X 10.6, 10.7: Version v1.0.3 Mac OS X 10.5: Version v1.0.2 Older: unkown
History
v1.1 - Minor compatibility update
As of Mac OS X 10.6, diskutil listRAID is a deprecated synonym for diskutil appleRAID list.
Replaced that command for future use, dropping support for 10.5 systems. (Use v1.0.2 instead)
v1.0.2 - Minor update
New features:
- Added log messages. Test running and error notification.
v1.0.1 - Minor update
New features:
- Added Hostname in mail's subject
v1.0 - Initial commit from copypasted code
Feature basic check of Apple's software RAID system with mail notification to an admin.