From mboxrd@z Thu Jan  1 00:00:00 1970
From: jmk@plan9.bell-labs.com
To: 9fans@cse.psu.edu
Subject: Re: [9fans] ide file server with mirroring
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Date: Wed,  5 Sep 2001 10:54:27 -0400
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Following on from what Nemo and Geoff have said, the most common failure
now seems to be the power supply in the computer case. During the past year
we've had a couple dozen fail, a lot of them while on a UPS, so it's not
just the off/on/power-dip stress. That, coupled with the apparent fragility
of ATA drives, makes designing a reliable hardware+filesystem more of a
challenge.

In our computer room there are 2 or 3 IDE-raid boxes (not running a Plan 9
filesystem) and I believe in the 6 months or so they've been there at least
one drive has failed. However, the boxes have redundant power supplies and
the drives can be hot-swapped (at some performance cost during the update),
so getting the hardware reliability is possible at a reasonable monetary and
performance cost.