On 2006-04-12 16:59:26 -0400, Bowie Bailey wrote: > > - What kind of pitfalls should we be aware of? > > Some people have complained about throughput issues with GFS. Our > application doesn't require high throughput, so I can't comment on > this. I haven't found any issues in my testing so far. > Well, a thing I _think_ we've seen a few times is that the case of many simultaneous writes to different files in different directories is MUCH faster than many simultaneous writes to different files in the same directory. I think this may have been mentioned before on-list, IIRC it's a design trade-off, something to do with GFS's efforts to preserve strict unix-like consistency (generally regarded as a major advantage of GFS over the horrors of NFS), directory metadata about the files needs to be updated an awful lot in the same directory case, and the directory therefore needs to be locked for update an awful lot, which can lead to much slowdown. I don't have hard numbers, nor available facilities to generate them right now, so feel free to regard this as FUD. -- Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster
