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. 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 ? 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. 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.
