[Asterisk-Users] UPS for Asterisk

[Remco Barende]

>> Indeed, I'm thinking of using 2 CompactFlash ATA disks. One fully
>> read
>> only with just a small partition writable that will keep
>> /etc/asterisk
>> (astlinux mounts read-only always and only mounts read-write if you
>> need
>> to change/save the config). No worries about unclean shutdown.
>>
>> The second disk I will use for voicemail, and I can swap it every
>> year
>> before it wears down.
>
> Better than that, mirror the disk.  Then when one drive fails
> Linux will automatically use the other disk.  You can go one step
> more and define a third disk as a "hot spare" then after Linux
> detects the drive failure and switches to the surviving twin
> it will also bring up the hot spare and begin building a replacement
> for the dead twin.  You can then swap out the dead drive with no
> need to power down the server and declare the new drive as the
> new "hot spare"  I would mirror the read-only patition also
>
> It you truely want "5 nines" you have to set things up so that you
> can do normal maintanance (swapping out drives, power supplies and
> the like without powering down.

I thought of that but that's not much use with flash disks. Flash can only 
be written to a number of times. If I would do raid1 on two flash drives 
and they reach that limit they might die shortly after each other.

Raid1 is a good solution when doing real harddrives. I may consider doing 
raid1 with two laptop harddiscs. laptop drives do not consume a lot of 
power nor do they produce any heat.

Alternatively I could consider hardware raid1 with one ATA flash drive 
and one laptop drive, chances of them dying both at the same time are 
slim.

I will do some testing on the behaviour of * when the partition where 
voicemail is stored is failing. If * will just skip voicemail that would 
be good enough for me, I don't care about voicemail being unavailable, i 
just dont want it to bring the whole box down.