> -----Original Message----- > From: linux-cluster-bounces@xxxxxxxxxx [mailto:linux-cluster- > bounces@xxxxxxxxxx] On Behalf Of Jankowski, Chris > Sent: Wednesday, November 10, 2010 3:04 PM > To: linux clustering > Subject: Re: Starter Cluster / GFS > > Robert, > > One reason is that with GFS2 you do not have to do fsck on the surviving > node after one node in the cluster failed. > > Doing fsck ona 20 TB filesystem with heaps of files may take well over an > hour. > > So, if you built your cluster for HA you'd rather avoid it. > > The locks need to be recovered, but this is much faster operation and fairly > time bound. Fsck is not. > > Regards, > > Chris Jankowski > > -----Original Message----- > From: linux-cluster-bounces@xxxxxxxxxx [mailto:linux-cluster- > bounces@xxxxxxxxxx] On Behalf Of Marti, Robert > Sent: Thursday, 11 November 2010 07:51 > To: 'linux clustering' > Subject: Re: Starter Cluster / GFS > > > -----Original Message----- > > From: linux-cluster-bounces@xxxxxxxxxx [mailto:linux-cluster- > > bounces@xxxxxxxxxx] On Behalf Of Nicolas Ross > > Sent: Wednesday, November 10, 2010 1:32 PM > > To: linux clustering > > Subject: Re: Starter Cluster / GFS > > > > > We had to make similar changes to our application. > > > > > > Avoid allowing two (or more) hosts to create small files in the same > > > shared directory within a GFS filesystem. That particular case > > > scales poorly with GFS. > > > > > > If you can partition things so that two hosts will never create > > > files in the same directory (we used a per-host directory structure > > > for our application), or perhaps direct all write operations to one > > > host while other hosts only read from GFS, it should perform well. > > > > Ok, I see. Our applications will read/write into its own directory > > most of the time. In the rare cases when it'll be possible that 2 > > nodes read/writes to the same directory, it'll be for php sessions > > files. If we ever need to reach to this stage, we'll have to make a > > custom session handler to put them into a central memcached or > something else... > > > > If that's the case, why look at shared storage at all? > > -- In this scenario, he's not building the apps for HA (single server at a time, except maybe for sessions) he's not using massive filesystems (5-6TB total)... The overhead involved in managing shared storage isn't typically worth it if you're not going to leverage the shared portion of it. Rob Marti -- Linux-cluster mailing list Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster
