An adage for gmirror users

Wojciech Puchar wojtek at
Wed Jun 3 20:58:20 UTC 2009

> My mirror gm0 consists of two SATA disks, ad4 and ad6. Now, I have a
> finicky controller that sporadically spits out READ_DMA and READ_DMA48

or bad cables.

> timeouts inexplicably. So at some point in time immemorial after
> installing the last kernel, ad4 suffered a number of READ_DMA48 errors
> and dropped out without being removed from the mirror's provider list .
> So when I installed my new flashy kernel with all my filesystems
> mounted, it was put into /boot/kernel on the mirror, which at that point
> consisted of only ad6. On boot, the loader grabbed the kernel from

i simply have in crontab a script running once per hour:

/sbin/gmirror status|grep -q DEGRADED && \\
mail -s "gmirror failure" myphonenumber at </dev/null

anyway - what a sense of using gmirror without regularly checking of 
failures at all?

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