On Mon, Jul 01, 2013 at 02:04:24PM -0400, Scott Sipe wrote: > On Mon, Jul 1, 2013 at 1:04 PM, Jeremy Chadwick <j...@koitsu.org> wrote: > > > On Mon, Jul 01, 2013 at 12:23:45PM -0400, Paul Mather wrote: > > > On Jul 1, 2013, at 11:49 AM, Jeremy Chadwick <j...@koitsu.org> wrote: > > > > > > > Of course when I see lines like this: > > > > > > > > Trying to mount root from zfs:zroot > > > > > > > > ...this greatly diminishes any chances of "live debugging" on the > > > > system. It amazes me how often I see this come up on the lists -- > > people > > > > who have ZFS problems but use ZFS for their root/var/tmp/usr. I wish > > > > that behaviour would stop, as it makes debugging ZFS a serious PITA. > > > > This comes up on the list almost constantly, sad panda. > > > > > > > > > I'm not sure why it amazes you that people are making widespread use of > > ZFS. > > > > It's not widespread use of ZFS. It's widespread use of ZFS as their > > sole filesystem (specifically root/var/tmp/usr, or more specifically > > just root/usr). People are operating with the belief that "ZFS just > > works", when reality shows "it works until it doesn't". The mentality > > seems to be "it's so rock solid it'll never break" along with "it can't > > happen to me". I tend to err on the side of caution, hence avoidance of > > ZFS for critical things like the aforementioned. > > > > It's different if you have a UFS root/var/tmp/usr and ZFS for everything > > else. You then have a system you can boot/use without issue even if ZFS > > is crapping the bed. > > > > > > ... > > > > > > 95% of FreeBSD users cannot debug kernel problems**. To debug a kernel > > problem, you need: a crash dump, a usable system with the exact > > kernel/world where the crash happened (i.e. you cannot crash 8.4 ZFS and > > boot into 8.2 and reliably debug it using that), and (most important of > > all) a developer who is familiar with kernel debugging *and* familiar > > with the bits which are crashing. Those who say what you're quoting are > > often the latter. > > > > > > ... > > > > > > But the OP is running -RELEASE, and chooses to run that, along with use > > of freebsd-update for binary updates. Their choices are limited: stick > > with 8.2, switch to stable/X, cease use of ZFS, or change OSes entirely. > > > > So I realize that neither 8.2-RELEASE or 8.4-RELEASE are stable, but I > ultimately wasn't sure where the right place to go for discuss 8.4 is?
For filesystem issues, freebsd-fs@ is usually the best choice, because it discusses filesystem-related thing (regardless of stable vs. release, but knowing what version you have of course is mandatory). freebsd-stable@ is mainly for stable/X related discussions. Sorry to add pedanticism to an already difficult situation for you (and I sympathise, particularly since the purpose of the lists is often difficult to discern, even with their terse descriptions in mailman). > Beyond the FS mailing list, was there a better place for my question? I'll > provide the other requested information (zfs outputs, etc) to wherever > would be best. Nope, not as far as I know. The only other place is send-pr(1), once you have an issue that can be reproduced. Keep in mind, however, that none of these options (mailing lists, send-pr, etc.) mandate a response from anyone. You/your business (see below) should be aware that there is always the possibility no one can help solve the actual problem; as such it's important that companies have proper upgrade/migration paths, rollback plans, and so on. > This is a production machine (has been since late 2010) and after tweaking > some ZFS settings initially has been totally stable. I wasn't incredibly > closely involved in the initial configuration, but I've done at least one > binary freebsd-update previously. Well regardless it sounds like moving from 8.2-RELEASE to 8.4-RELEASE causes ZFS to break for you, so that would classify as a regression. What the root cause is, however, is still unknown. Point: 8.2-RELEASE came out in February 2011, and 8.4-RELEASE came out in June 2013 -- that's almost 2.5 years of changes between versions. The number of changes between these two is major -- hundreds, maybe thousands. ZFS got worked on heavily during this time as well. I tend to tell anyone using ZFS that they should be running a stable/X (particularly stable/9) branch. I can expand on that justification if needed, as it's well-founded for a lot of reasons. > Before this computer I had always done source upgrades. ZFS (and the > thought of a panic like the one I saw this weekend!) made me leery of doing > that. We're a small business--we have this server, an offsite backup > server, and a firewall box. I understand that issues like this are are > going to happen when I don't have a dedicated testing box, I just like to > try to minimize them and keep them to weekends! Understood. > It sounds like my best bet might be to add a new UFS disk, do a clean > install of 9.1 onto that disk, and then import my existing ZFS pool? I would suggest starting with this: Get stable/9 from the place I mentioned, burn an ISO or dd a memstick image to a USB flash drive, and then drop to the Fixit shell (or whatever it's called now, I forget), then try to import your pool. If it works, then you know migrating to stable/9 should work for you (i.e. that the bug/issue/whatever is likely fixed in stable/9), or that some settings/stuff you've configured (probably /boot/loader.conf -- yes I am quite aware of the screwing about required there for ZFS on 8.2) on 8.2 is no longer needed or causing problems on 8.4. If it doesn't work, then you/your company need to work out what your next choice of action should be. -- | Jeremy Chadwick j...@koitsu.org | | UNIX Systems Administrator http://jdc.koitsu.org/ | | Making life hard for others since 1977. PGP 4BD6C0CB | _______________________________________________ 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"
