[OpenAFS] OpenAFS with RAID

Chaskiel M Grundman cg2v@andrew.cmu.edu
Wed, 28 Dec 2005 10:59:02 -0500


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--On Wednesday, December 28, 2005 03:39:34 PM +0000 Paul Robins=20
<paul@paulrobins.alldaypa.com> wrote:

> If either of you could weigh in on AFS on top of DRBD i'd appreciate it,
> I'm not fully up on whether a second server with an identical filesystem
> could be made to take over a crashed AFS machine.

There are a couple of issues

1) would DRBD actually notice that the storage device on the primary node=20
is "hanging" and switch over to the secondary? I didn't think that most=20
heartbeat services would catch this
2) there would be a significant delay bringing up the secondary node as a=20
fileserver: Since the volumes were likely to all be "attached" (in use) by=20
the primary node's fileserver at the time of the failover, the DRBD=20
partition would need to be salvaged (a secondary fsck of the afs metadata)=20
before the fileserver could be started on the secondary machine.
3) you would need to do some sort of IP address takeover in order for=20
clients to contact the correct machine to get at the data. (The AFS=20
architecture provides better ways to do this, but the tools for using them=20
in a case like this aren't there at the moment)
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