Date: Thu, 10 Dec 2015 10:05:16 -0500 From: Michael Jung <mikej@mikej.com> To: "Michael B. Eichorn" <ike@michaeleichorn.com> Cc: freebsd-stable@freebsd.org, Jan Bramkamp <crest@rlwinm.de>, owner-freebsd-stable@freebsd.org Subject: Re: Periodic jobs triggering panics in 10.1 and 10.2 Message-ID: <5a51afa00214d0244856dee137b99b94@mail.mikej.com> In-Reply-To: <1449758755.31831.80.camel@michaeleichorn.com> References: <34FA7D40-8758-460D-AC14-20B21D2E3F8D@ebureau.com> <1449619470.31831.9.camel@michaeleichorn.com> <56682278.4040302@sorbs.net> <56683FC1.3050001@rlwinm.de> <5668AAB1.1080003@sorbs.net> <1449703798.4355.27.camel@michaeleichorn.com> <56697B32.7050705@sorbs.net> <1449758755.31831.80.camel@michaeleichorn.com>
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On 2015-12-10 09:45, Michael B. Eichorn wrote: > On Thu, 2015-12-10 at 14:16 +0100, Michelle Sullivan wrote: >> Michael B. Eichorn wrote: >> > >> > I sorry, but I really don't get your point, PCBSD has shown a great >> > reason why zfs on root and on laptops/desktops is a good idea... >> > boot >> > >> >> It has? As this is FreeBSD not PCBSD I must have missed that one... > > PCBSD is effectively a 'distribution' of FreeBSD, It is just a > different set of defaults and packages with different options. I mean > you can make a FreeBSD install PCBSD by swapping out th repo. I think > using them as an example is within reason. > >> > environments. They have pretty much figured out how to use >> > snapshots to >> > go from A-B ping-pong installations to A-B-C-D-E.... installations. >> > I >> > am even aware of people using it to run Release and Current on the >> > same >> > machine. Unfortunately at the moment the system requires GRUB, but >> > there is ongoing work to add the ability to the FreeBSD bootloader. >> > >> >> But it's not there yet... and would you consider this for someone who >> is >> not that technical? (Not that technical != non technical) > > I will concede that until the bootloader work is done I would not > recommend boot environments to a less technical user. > >> > Further IIRC zfs send-receive has a history involving a developer >> > who >> > wanted a better rsync for transfering his work to a laptop. >> >> As I said previously these are the features are the ones you listed >> as >> 'additional' (ie your after thoughts) > > It wasn't me in the previous email, but if there is any marginal > benifit over UFS for a laptop/desktop it is probably send-receive. > >> >> >> > In addition >> > we have pretty much Moore's Lawed our way to the point where a new >> > laptop today can out spec a typical server from when ZFS was first >> > implemented. >> > >> >> I have yet to see a 6 spindle laptop... in fact I've yet to see a 3+ >> spindle laptop... > > Your are correct here, I was mostly tring to point out the CPU and RAM > on client machines are now up to what servers were at. That said, I > have been running mirrored SSDs since it became an option. > >> I could be recalling wrongly but I'm pretty sure a number of emails >> have >> been seen on @freebsd.org lists that say, "don't use zfs on single >> spindle machines".. what I do know is that personally I have a >> machine >> with a hardware RAID and 16 drives... Initially I configured it with >> 1 >> large LD RAID6+HSP and put zfs on it (because I wanted to take >> advantage >> of the 'on the fly compression')... it's a backup store... and every >> scrub checksum errors were found - on files that had not been written >> to >> since the last scrub. I reconfigured it as 16 x single disk RAID0 >> drives - identical hardware, just a different config, put raidz2 >> across >> 15 drives and left one as a spare and now I don't have any errors >> except >> when a drive fails and even then it 'self heals'... > > Hmm, the advice that ZFS advocates such a Allan Jude have been giving > of late is that ZFS can work in single spindle. It is just that it is > less safe (like any single disk) but is not more data-loss prone than > other forms of striping. > >> > Hiding features because you 'can' shoot your foot off is hardly a >> > typical UNIXy way of thinking anyway. >> >> Not talking about 'hiding' features, even though this thread started >> with someone suggesting 'hiding' a bug by using -J and -j options for >> cron....! > > I will fess up, It was me who suggested -J and -j, but it was more in > the sense of improving the work-around (the OP had just stopped running > cron in jails). It was not ment to imply the bug shouldn't be fixed, > all bugs should be fixed and not hidden. > >> Look I'm being quite confrontational here in this message, there are >> a >> lot of people that don't like me here, and I don't like some of them >> myself so the feeling is very mutual, the point I'm trying to make is >> quite simple. > > I must admit to being a bit 'heated' too, but I kind of like debates > and I take no personal grievance, or have any problem with you. It is a > technical discussion with strongly held beliefs. Further despite the > emotions I applaud the continued use of professional language. > >> I see it almost daily, FreeBSD people saying "install ZFS that'll >> solve >> your problems" and "ZFS it's the way forward" ... just the same way >> as >> they did with PkgNG etc... (not going to say anything on that, don't >> want an argument on that, this is not about 'that'..) >> >> ZFS has it's place, it is very good at some things, it brings >> features >> that people need. >> ZFS does not work (is not stable) on i386 without recompiling the >> kernel, but it is presented as an installation option. >> ZFS is compiled in by default in i386 kernels without the necessary >> option change to make it "stable". >> We have been told the kernel option change will never be put there by >> default. >> freebsd-update will remove/replace a kernel compiled with the option >> i386 is still a teir1 platform. >> 32bit laptops are still available for purchase at major retailers >> (eg: >> Bestbuy) > > You are correct, ZFS is not a panacia, and they clearly have different > use cases. I would never use ZFS for an embedded system, or UFS for a > big-iron fileserver. I think our disagreement is on the laptop/desktop, > I think both technologies are able to handle the laptop/desktop just > fine, so it really comes down to personal preference in what features > are most important. I responded so forcefully previously because I > perceived that you were saying ZFS was the wrong choice for that > workload. I just don't see evidence that for a typical laptop/desktop, > which I take to mean an amd64 machine (probably newer than core2) and > with at least 4GB of RAM, is likly to have a significant problem > running either. > > As to i386, I concur running ZFS on them at all is questionable. 386 > was outside of the design intent, and it should not be done. I suppose > I was living in my happy place where i368 is slowly being phased out of > the hands of non-expert users. *sigh* Best Buy *shakes head*. > >> I do not believe zfs should be default available when it is not >> stable >> on all teir1 platforms. I believe it should be fixed to be stable >> before its added as an installation option to teir1 platforms and if >> it >> cannot/willnot be fixed to 'stable' status then it should never make >> it >> into the defaults available... it should be limited to be in advanced >> installations where the people who know will probably know how to fix >> things or what to expect. > > I think the defaults are going to get even muddier than this, after all > IIRC arm is going to be tier1 in 11. I have heard nothing at all about > ZFS on arm, but even if the processors could handle it most arm boards > don't have much RAM. > > In the past where amd64 and i386 were the tier1 supports I could see > some advantage to keeping the defaults more in sync with each other. > However, given how different arm can be perhaps it is time to > reconsider the defaults in i386. I suppose the devs may have a better > reason for ZFS is i386, but _this_ is probably a productive > conversation to have. > >> ..anyhow my thoughts on the subject.. why I don't know because in >> the >> time it has taken me to write this, it occurred to me, I don't give a >> stuff really if people see FreeBSD as stable or unstable anymore. I >> put >> forward experiences and what I see and the questions/answers I have >> to >> deal with here and am usually ignored or argued with and I spend 30 >> minutes (or more) writing emails explaining stuff/defending myself to >> people who don't care and think (like me) they know best when I could >> actually be doing the work I get paid for. On that note I will leave >> you to considerand discard my thoughts as trivial and pointless and >> reply as such and get on with making my stuff better by actually >> listening to people who use it. > > Again, I appreciate your points, I think you just came off originally > as very dismissive that ZFS is an option for laptops. I reacted > strongly, as have you, but I take no malice or offense, nor have any > towards yourself. Your arguements have spurred thinking at least on my > part as to what the defaults should be for i386. If anyone is being the > ID10T here, it is probably me anyway. > > If I might make a recommendation, I think that a separate thread about > the i386 defaults is probably in order as I imagine the length of these > emails has probably turned most people off. > _______________________________________________ > freebsd-stable@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to > "freebsd-stable-unsubscribe@freebsd.org" We all know that with ZFS you two copies of metadata, but you can also set copies=2 and have two copies of your data spread across your single device vdev. This saved me on a single drive when it started failing. This blog talks about single disk usage https://blogs.oracle.com/relling/entry/zfs_copies_and_data_protection --mikej
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