The system in question has 8GB of ram. It never paged during the import (unless I was asleep at that point, but anyway).
It ran for 52 hours, then started doing 47% kernel cpu usage. At this stage, dtrace stopped responding, and so iopattern died, as did iostat. It was also increasing ram usage rapidly (15mb / minute). After an hour of that, the cpu went up to 76%. An hour later, CPU usage stopped. Hard drives were churning throughout all of this (albeit at a rate that looks like each vdev is being controller by a single threaded operation). I'm guessing that if you don't have enough ram, it gets stuck on the use-lots-of-cpu phase, and just dies from too much paging. Of course, I have absolutely nothing to back that up. Personally, I think that if L2ARC devices were persistent, we already have the mechanism in place for storing the DDT as a "seperate vdev". The problem is, there is nothing you can run at boot time to populate the L2ARC, so the dedup writes are ridiculously slow until the cache is warm. If the cache stayed warm, or there was an option to forcibly warm up the cache, this could be somewhat alleviated. Cheers _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
