> If you have more comments, or especially if you think I reached the wrong > conclusion, please do post it. I will post my continuing results.
I think your conclusions are correct. The main thing you're seeing is the combination of gzip-9 being incredibly CPU-intensive with our I/O pipeline allowing too much of it to be scheduled in parallel. The latter is a bug we will fix; the former is the nature of the gzip algorithm. One other thing you may encounter from time to time is slowdowns due to kernel VA fragmentation. The CPU you're using is 32-bit, so you're running a 32-bit kernel, which has very little KVA. This tends to be more of a problem with big-memory machines, however -- e.g. a system with 8GB running a 32-bit kernel. With 768MB, you'll probably be OK, but it's something to be aware of on any 32-bit system. You can tell if this is affecting you by looking for kernel threads stuck waiting to allocate a virtual address: # echo '::walk thread | ::findstack -v' | mdb -k | grep vmem_xalloc Jeff _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
