Hi Deian, On Fri, Oct 10, 2008 at 8:51 PM, Deian Chepishev <dchepishev at nexbrod.com>wrote: > Hi guys, > > I have a few questions about UNIFY and volume creation. > > You will find my config files at the end of this post. I will post my > questions before the config. > > 1. I want to use writebehind and readahead translators, because I think > it speeds the transfer. Can you please take a look i let me know if it > is correctly written. > I basically do this: > create one volume from the exported bricks lets say "unify" > create another volume named "writebehind" with subvolumes unify > then create another volume named "readahead" with subvolumes writebehind > then mount the volume named writebehind. If you are using --volume-name option to glusterfs to attach to writebehind, then you are bypassing readahead and hence will not get readahead functionality. If you want to have both read-ahead and write-behind functionalities, do not specify --volume-name option (or give readahead as the argument to the option, if at all you want to use it). > > Is this correct or there is a better way to do this? > > 2. Does the UNIFY volume adds special attributes to the files like AFR ? No > > > 3. Is there a way to specify in /etc/fstab exactly which volume I want > to mount? > In the docs they say: > > 192.168.0.1 /mnt/glusterfs glusterfs defaults 0 0 > > OR > > /etc/glusterfs/glusterfs-client.vol /mnt/glusterfs glusterfs defaults 0 0 > > However I dont know which volume will be mounted if I have more than one > defined in the config as in my case. > Is there a way to point which one to be mounted. simple way would be to have the volume which you want to attach to as the last (bottom most) volume in volume-specfication file (you have to delete the unnecessary volumes or disconnect them from the graph by not having them in the subvolumes list of any other volumes). > > 4. I use Gigabit network and noticed that when I use dd to write a file > I get around 115 MB/sec and during this time the glusterfs process > spends around 30-40% > CPU load on machine with Quad Core 2GHz Xeon, which seem quite high load > to me. > > If I mount the GFS system locally on the server glusterfs loads the CPU > to 100% > > Is this high load normal or I am missing something ? > What can I do to lower the load ? > > > > I have the following server and client files: > > > volume brick > type storage/posix > option directory /storage/gluster-export/data/ > end-volume > > volume brick-ns > type storage/posix > option directory /storage/gluster-export/ns > end-volume > > ### Add network serving capability to above brick. > > volume server > type protocol/server > option transport-type tcp/server > subvolumes brick brick-ns > option auth.ip.brick.allow 10.1.124.* > option auth.ip.brick-ns.allow 10.1.124.* > end-volume > > ========================= > > Client: > > volume brick1-stor01 > type protocol/client > option transport-type tcp/client > option remote-host 10.1.124.200 > option remote-subvolume brick > end-volume > > volume brick1-stor02 > type protocol/client > option transport-type tcp/client > option remote-host 10.1.124.201 > option remote-subvolume brick > end-volume > > volume brick-ns1 > type protocol/client > option transport-type tcp/client > option remote-host 10.1.124.200 > option remote-subvolume brick-ns > end-volume > > > volume brick-ns2 > type protocol/client > option transport-type tcp/client > option remote-host 10.1.124.201 > option remote-subvolume brick-ns # Note the different remote volume name. > end-volume > > volume afr-ns > type cluster/afr > subvolumes brick-ns1 brick-ns2 > end-volume > > volume unify > type cluster/unify > option namespace afr-ns > option scheduler rr > option scheduler alu # use the ALU scheduler > option alu.limits.min-free-disk 5% # Don't create files one a > volume with less than 5% free diskspace > option alu.limits.max-open-files 10000 # Don't create files on a > volume with more than 10000 files open > option alu.order > disk-usage:read-usage:write-usage:open-files-usage:disk-speed-usage > option alu.disk-usage.entry-threshold 100GB # Kick in if the > discrepancy in disk-usage between volumes is more than 2GB > option alu.disk-usage.exit-threshold 50MB # Don't stop writing to > the least-used volume until the discrepancy is 1988MB > option alu.open-files-usage.entry-threshold 1024 # Kick in if the > discrepancy in open files is 1024 > option alu.open-files-usage.exit-threshold 32 # Don't stop until 992 > files have been written the least-used volume > option alu.stat-refresh.interval 10sec # Refresh the statistics used > for decision-making every 10 seconds > subvolumes brick1-stor01 brick1-stor02 > end-volume > > volume writebehind > type performance/write-behind > option aggregate-size 512kb # default is 0bytes > option flush-behind on # default is 'off' > subvolumes unify > end-volume > > volume readahead > type performance/read-ahead > option page-size 512kB > option page-count 4 > option force-atime-update off > subvolumes writebehind > end-volume > > > > Sorry for the long post and thank you in advance. > > > _______________________________________________ > Gluster-users mailing list > Gluster-users at gluster.org > http://zresearch.com/cgi-bin/mailman/listinfo/gluster-users > regards, -- Raghavendra G -------------- next part -------------- An HTML attachment was scrubbed... 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