[prev in list] [next in list] [prev in thread] [next in thread] 

List:       gfs-users
Subject:    Re: [gfs-users] GFS as a shared root fs
From:       David Teigland <teigland () sistina ! com>
Date:       2001-01-30 17:23:50
[Download RAW message or body]

On Tue, Jan 30, 2001 at 02:09:31PM +0100, Tudor TEUSAN wrote:
 
> I have one big question (it might be stupid !): If the above
> configuration has a chance to work, where should be the stomithd
> (stomith daemon) initialized ? Can it be started after the root gfs is
> mounted ? When mounting a file system, can a node decide to STOMITH the
> other nodes (and hence make use of stomithd and a stomith agent(s)) and
> if yes, is there any possibility to still have a shared root fs ?

Very good question.  (This is why we originally had all the stomith stuff
inside the kernel.)  This is only a problem when all GFS nodes die at once and
the lock server remains running (or restores its lock state on restart).  The
first machine to re-mount in this situation needs to stomith other possibly
hung machines in the memexp mount routine.  As you've seen, the stomith's won't
work because stomithd and the agents are not available.

There are two ways around this problem:

1. Have one machine available without a root GFS file system which can mount
   the file system and do the recovery.  There are various approaches to 
   using this machine which minimize the likelihood of requiring any manual 
   intervention - I haven't thought very much about it.

2. Reset the lock state on the lock server before the GFS nodes come back.
   If memexpd was not storing lock state to persistent storage, the process
   can simply be restarted, otherwise the lock state needs to be cleared
   before restarting memexpd.  This will eliminate the need for stomith at
   mount time.  This may or may not require manual intervention. 


-- 
Dave Teigland  <teigland@sistina.com>
_______________________________________________
gfs-users mailing list
gfs-users@sistina.com
http://lists.sistina.com/mailman/listinfo/gfs-users
Read the GFS Howto:  http://www.sistina.com/gfs/Pages/howto.html

[prev in list] [next in list] [prev in thread] [next in thread]