Pawel Jakub Dawidek wrote:
This is what I see on Solaris (hole is 4GB):# /usr/bin/time dd if=/ufs/hole of=/dev/null bs=128k real 23.7 # /usr/bin/time dd if=/zfs/hole of=/dev/null bs=128k real 21.2 # /usr/bin/time dd if=/ufs/hole of=/dev/null bs=4k real 31.4 # /usr/bin/time dd if=/zfs/hole of=/dev/null bs=4k real 7:32.2
This is probably because the time to execute this on ZFS is dominated by per-systemcall costs, rather than per-byte costs. You are doing 32x more system calls with the 4k blocksize, and it is taking 20x longer.
That said, I could be wrong, and yowtch, that's much slower than I'd like! --matt _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
