On 09/12/15 13:45, Michelle Sullivan wrote:> Michael B. Eichorn wrote: >> On Tue, 2015-12-08 at 16:31 -0600, Dustin Wenz wrote: >> >>> I suspect this is a zfs bug that is triggered by the access patterns >>> in the periodic scripts. There is significant load on the system when >>> the scheduled processes start, because all jails execute the same >>> scripts at the same time. >>> >>> I've been able to alleviate this problem by disabling the security >>> scans within the jails, but leave it enabled on the root host. >>> >> >> To avoid the problem of jails all starting things at the same time, use >> the cron(8) flags -j and -J to set a 'jitter' which will cause cron to >> sleep for a random period of specified duration (60 sec max). Cron >> flags can be set using the rc.conf variable 'cron_flags'. >> _______________________________________________ >> > > No that will just hide it (if successful at all) and it won't work in > all cases. > > ... i386 is even worse for similar (not the same) instability triggered > by the same scripts ... because zfs should not be used with the stock > i386 kernel (which means if you're using it the whole patching process > with freebsd-update won't work or will 'undo' your kernel config.)Do you have a good idea how to prevent users from shooting themselves in the foot by running ZFS on 32 Bit kernels?> Personally I think zfs should be optional only for 'advanced' users and > come with a whole host of warnings about what it is not suitable for.... > however, it seems to be treated as a magic bullet for data corruption > issues yet all I have seen is an ever growing list of where it causes > problems.. when did UFS become an unreliable FS that is susceptible to > chronic data corruption?As storage capacity grew a lot faster than reliability. UFS is a good file system for its time, but it trusts hardware absolutely. Modern hardware doesn't deserve this level of trust. ZFS detects and recovers without dataloss from most errors caused by the limited hardware reliability. ZFS isn't just a tool to deal with hardware limitations it's also a convenience I no longer want to give up. Snapshots and replication streams simplify backups and a background scrub once a week (or month) sure beats waiting for fsck.
Jan Bramkamp wrote:> On 09/12/15 13:45, Michelle Sullivan wrote: >> >> No that will just hide it (if successful at all) and it won't work in >> all cases. >> >> ... i386 is even worse for similar (not the same) instability triggered >> by the same scripts ... because zfs should not be used with the stock >> i386 kernel (which means if you're using it the whole patching process >> with freebsd-update won't work or will 'undo' your kernel config.) > > Do you have a good idea how to prevent users from shooting themselves > in the foot by running ZFS on 32 Bit kernels?Yes default not to having zfs available on any platform and allow people that know what they are doing to turn it on.... I mean "prevent users from shooting themselves in the foot" - how about by not having an option to install a zfs root on the default install disks?> >> Personally I think zfs should be optional only for 'advanced' users and >> come with a whole host of warnings about what it is not suitable for.... >> however, it seems to be treated as a magic bullet for data corruption >> issues yet all I have seen is an ever growing list of where it causes >> problems.. when did UFS become an unreliable FS that is susceptible to >> chronic data corruption? > > As storage capacity grew a lot faster than reliability.Yeah, that's why we have these multi-tes-of-terrabyte laptops that must have a zfs root install...> > UFS is a good file system for its time, but it trusts hardware > absolutely. Modern hardware doesn't deserve this level of trust.Ok at this point we have to question things... Does your average home machine need zfs? (because windows doesn't) ... does your average laptop require zfs (or even benefit) ...? In fact when I look at it, I'm running 70+ servers and a few desktops and I'm running 5 of them with zfs... 2 of them absolutely need it, 2 of them are solaris (which probably doesn't count and certainly doesn't have relevance to FreeBSD) the other is a 2005 P4 based server that is completely unusable because zfs on i386 doesn't work with the stock kernel.... and guess what ... it has 73G 15k SCSI Server drives in it so it probably has reliable hardware that doesn't suffer from "Modern hardware doesn't deserve this level of trust"> ZFS detects and recovers without dataloss from most errors caused by > the limited hardware reliability.Currently I've had more problems with the reliability of zfs in FreeBSD than reliability of hardware.. I do get your point though...> > ZFS isn't just a tool to deal with hardware limitations it's also a > convenience I no longer want to give up. Snapshots and replication > streams simplify backups and a background scrub once a week (or month) > sure beats waiting for fsck.Now this is the one set of reasons I can really appreciate and had it been the opening argument I'd have understood your position, but it seems this is a side note to the above and the above is where I see it's completely useless... When ZFS was first developed a friend and I in Sun had lots of fun setting up servers where we just chucked any old drives we could lay our hands on into a pool ... this we found very cool and this was where 'unreliable' hardware was an understatement - the drives were pulled from machines because SMART (and other tools) were reporting the drive(s) failing..... but it was a work around for bad sectors etc... Seriously though the default to install with zfs and root on zfs is a really bad idea - the people who know how not to shoot themselves in the foot are those people that don't need a selectable option in the install because they know how to configure it... they're the people who will probably be in every manual and advanced option they can find anyhow (or just using boot servers and predefined install scripts)....!! Regards, -- Michelle Sullivan http://www.mhix.org/