On Mar 31, 2013, at 7:04 AM, Victor Balada Diaz <vic...@bsdes.net> wrote:
> On Wed, Mar 27, 2013 at 11:22:14PM +0200, Alexander Motin wrote: >> Hi. >> >> Since FreeBSD 9.0 we are successfully running on the new CAM-based ATA >> stack, using only some controller drivers of old ata(4) by having >> `options ATA_CAM` enabled in all kernels by default. I have a wish to >> drop non-ATA_CAM ata(4) code, unused since that time from the head >> branch to allow further ATA code cleanup. >> >> Does any one here still uses legacy ATA stack (kernel explicitly built >> without `options ATA_CAM`) for some reason, for example as workaround >> for some regression? Does anybody have good ideas why we should not drop >> it now? > > Hello, > > At my previous job we had troubles with NCQ on some controllers. It caused > failures and silent data corruption. As old ata code didn't use NCQ we just > used > it. > > I reported some of the problems on 8.2[1] but the problem existed with 8.3. > > I no longer have access to those systems, so i don't know if the problem > still exists or have been fixed on newer versions. > > Regards. > Victor. So what I hear you and Matthias saying, I believe, is that it should be easier to force disks to fall back to non-NCQ mode, and/or have a more responsive black-list for problematic controllers. Would this help the situation? It's hard to justify holding back overall forward progress because of some bad controllers; we do several Tbps off of AHCI controllers with NCQ enabled on FreeBSD 9.x, enough to make up a sizable percentage of the internet's traffic, and we see no problems. How can we move forward but also take care of you guys with problematic hardware? Scott _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
