[sheepdog-users] 0.4.0 this weekend :-)

Jens WEBER jweber at tek2b.org
Thu Jul 5 22:02:16 CEST 2012

> On 07/06/2012 12:37 AM, Alexandre DERUMIER wrote:
> >>> all sheeps of one node in the same zone? should be for saftey or? 
> > I'm not a sheepdog expert, but i think 1 zone by node is the right way ?
> > 
> Either is okay for sheepdog, gateway-only node don't count as storage
> node. Storage node (non-gateway-only node) matters because we need
> number of storage nodes >= copies to get cluster running (in case we
> don't set nohalt flat when formatting).
> There is something more to notice that non-gateway-only nodes can switch
> to gateway-only node automatically when EIO (for e.g. disk error)
> happens on local disks.
> So basically gateway-only mode mostly targets for the case that you just
> want to run sheep daemon as a request forwarder to the cluster (don't
> store any data locally). But yes, you can even run VM through QEMU
> without sheep daemon on local node!
> Also we have to keep in mind that we can make advantage of object cache
> (be it write-through mode or write-back mode) optionally to boost
> performance even for gateway-only node.

with sheep daemon on local node you can always connect to localhost, same config on all nodes. Nice for live migration for example.

> Thanks,
> Yuan

new init script is almost ready

--- snip ---
# sheepdog operation mode
# Mode:
#  non-gateway-only mode   -v >0, node count as storage
#  gateway-only mode       -g or -v 0, node don't count as storage

# Sheep daemon arguments
#  SHEEPDOG_START_SEQUENCE Postfix of sheeps to start, start one sheep per disc
#  SHEEPDOG_DEAMON_ARGS_1  Daemon arguments for sheep postfix _1
#  SHEEPDOG_PATH_1         SHEEPDOG_PATH for sheep postfix _1, mount point of disc1
#       Proper LSB systems will store sheepdog files in /var/lib/sheepdog.
#       The directory must be on a filesystem with xattr support.  In the case of ext3, user_xattr should be added  to  the
#       mount options.
# non-gateway-only mode:
#  SHEEPDOG_DEAMON_ARGS_1="-p 7000 -v 32"
#  SHEEPDOG_DEAMON_ARGS_2="-p 7001 -v 32"
#  SHEEPDOG_PATH_1="/var/lib/sheepdog/disc1"
#  SHEEPDOG_PATH_2="/var/lib/sheepdog/disc2"
# gateway-only mode:
#  SHEEPDOG_DEAMON_ARGS_1="-p 7000 -g"
--- snip ---

does sheep generate a pidfile, is there a secret option? 

 start-stop-daemon --start --quiet -m --pidfile ${PIDFILE}_sheep${SHEEP}.pid --exec $DAEMON

doesn't create the right pid, sheep forks, so at the moment only

 # BUG: pid in pidfile is wrong
 start-stop-daemon --stop --quiet --retry=TERM/30/KILL/5 --exec=$DAEMON

works and kill all

Cheers Jens

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