Hi, >> >> How did you perform the testing? It really matters. If you write a file on >> shared disk from one node, and read this file from another node, without, >> or with very little interval, the writing IO speed could decrease by ~20 >> times according my previous testing(just as a reference). It's a extremely >> bad situation for 2 nodes cluster, isn't? >> >> But it's incredible that in your case writing speed drop by >3000 times! > > > I simply used 'dd' to create a file with /dev/zero as a source. If there is > a better way to do this I am all ears.
Alright, you just did a local IO on ocfs2, then the performance shouldn't be that bad. I guess the ocfs2 volume has been used over 60%? or seriously fragmented? Please give info with `df -h`, and super block with debugfs.ocfs2, and also the exact `dd` command you performed. Additionally, perform `dd` on each node. You know, ocfs2 is a shared disk fs. So 3 basic testing cases I can think of are: 1. only one node of cluster do IO; 2. more than one nodes of cluster perform IO, but each nodes just read/write its own file on shared disk; 3. like 2), but some nodes read and some write a same file on shared disk. The above model is much theoretically simplified though. The practical scenarios could be much more complicated, like fragmentation issue that your case much likely is. >> Could you firstly do test on LVM, then DRBD, and then OCFS2? Let's blame >> on them more fairly. >> > If I do a similar write of a file to a directory that exists on a LVM LV I > get roughly 100 megabytes/sec. > > I can't write straight to the DRBD device, as that would entail wiping the > customer's OCFS2 filesystem, which I cannot do. OK, it's product environment. I can understand. Eric _______________________________________________ Ocfs2-users mailing list Ocfs2-users@oss.oracle.com https://oss.oracle.com/mailman/listinfo/ocfs2-users