[OpenAFS] OpenAFS with RAID
Thu, 29 Dec 2005 15:02:01 +0100
On Dec 29, 2005, at 12:28 PM, Christof Hanke wrote:
> Jeffrey Altman wrote:
>> Stephan Wiesand wrote:
>>> Wouldn't it be an option to not take over the IP address, but
>>> just the
>>> vice partition? Once failure of the peer is recognized and confirmed
>>> (which is a problem, I agree, but not at all AFS-specific):
>>> 1) stonith
>>> 2) mount the new vice partition and salvage it
>>> [ 2a) is there a need to restart the fileserver? ]
>>> 3) vos syncvldb
>> You would also require a
>> 4) vos syncserv
>>> There must be some thinko in all this, or people would be doing
>>> this a
>>> lot. What is it I'm overlooking?
>> I believe this scenario will not work because the VLDB entries for
>> of the volumes that are being mounted by Server B are listed as being
>> on Server A. Since Server A is unreachable, the volume server when
>> performing the "vos syncvldb" and "vos syncserv" steps will not be
>> to verify that the volume is no longer on Server A. Therefore, there
>> is now an "irreconcilable conflict" that will cause the vos
>> command to
>> "write a message to the standard error stream." The vos "command
>> removes volumes from file server machines." The quotes are from
>> the man
>> pages for "vos syncvldb" and "vos sycnserv".
> I guess, you con circumvent this, by moving the sysid as well.
> The hotswap may then work as follows:
> all /vicep* and /usr/afs (tranarc paths assumed) are on an external
> If/When fileserver A breaks, you shut it down.
> A standby node B, with the same OS than fileserver A (which is up
> to this place _no_ fileserver) mounts the stuff on the external
> storage. Then you startup the fileserver binary on that.
I did something like this years ago and it worked, but somehow I
still have a bad feeling about doing it ;-)
It was using FibreChannel devices, which are very easy to 'move'.
It included moving the IP address of the fileserver as well, to avoid
the syncvldb and syncserv headache.