Messages in this thread | | | Date | Mon, 18 Jun 2007 10:28:38 -0700 (PDT) | From | david@lang ... | Subject | Re: limits on raid |
| |
On Mon, 18 Jun 2007, Brendan Conoboy wrote:
> david@lang.hm wrote: >> in my case it takes 2+ days to resync the array before I can do any >> performance testing with it. for some reason it's only doing the rebuild >> at ~5M/sec (even though I've increased the min and max rebuild speeds and >> a dd to the array seems to be ~44M/sec, even during the rebuild) > > With performance like that, it sounds like you're saturating a bus somewhere > along the line. If you're using scsi, for instance, it's very easy for a > long chain of drives to overwhelm a channel. You might also want to consider > some other RAID layouts like 1+0 or 5+0 depending upon your space vs. > reliability needs.
I plan to test the different configurations.
however, if I was saturating the bus with the reconstruct how can I fire off a dd if=/dev/zero of=/mnt/test and get ~45M/sec whild only slowing the reconstruct to ~4M/sec?
I'm putting 10x as much data through the bus at that point, it would seem to proove that it's not the bus that's saturated.
David Lang - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |