Hello qihua,
Saturday, December 27, 2008, 7:04:06 AM, you wrote:
|
> |
After we changed the recordsize to 8k, We first used dd to move the data files around. We could see the time recovering a archive log dropped from 40mins to 4 mins. But when using iostat to check, the read io is about 8K for each read, the write IO is still 128k for each write. Then we used cp to move the data files around as someone said dd might not change the recordsize. after that, the time to recover a log file was drop from 4mins to 1/4 mins. So it seems dd doens't change the recordsize completely, and cp does. And is there any utility that could check the recordsize of an existing file? |
Probably what happened was that when you did your dd first old files were still occupying disk space, possibly outer regions. Then you deleted them and did cp again - this time zfs probably put most of the data on the outer regions of disks and your backup got faster. (it all depends on your file sizes and disk sizes).
--
Best regards,
Robert Milkowski mailto:mi...@task.gda.pl
_______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
