Date: Thu, 02 May 2019 09:27:36 +1000 From: Michelle Sullivan <michelle@sorbs.net> To: Chris <chrcoluk@gmail.com> Cc: freebsd-stable <freebsd-stable@freebsd.org> Subject: Re: ZFS... Message-ID: <6D7D690B-31DA-4A86-BB34-64A977B91D4F@sorbs.net> In-Reply-To: <CAOhm=5oRTkr6L037fzh4DKpqgMY5XJVp60t934en3%2BrGCnbFJw@mail.gmail.com> References: <30506b3d-64fb-b327-94ae-d9da522f3a48@sorbs.net> <CAOhm=5oRTkr6L037fzh4DKpqgMY5XJVp60t934en3%2BrGCnbFJw@mail.gmail.com>
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Michelle Sullivan http://www.mhix.org/ Sent from my iPad > On 02 May 2019, at 02:16, Chris <chrcoluk@gmail.com> wrote: >=20 > Your story is so unusual I am wondering if its not fiction, I mean all > sorts of power cuts where it just so happens the UPS fails every time, The only =E2=80=9Cfiction=E2=80=9D is the date.. was the 10th not the 19th M= arch... https://www.southcoastregister.com.au/story/5945663/homes-left-witho= ut-power-after-electrical-pole-destroyed-in-sanctuary-point-accident/ UPSes do glitch out sometimes, but rarely.. they do have problems when 11kv= comes down a 240v line though... > then you decide to ship a server halfway round the world, and on top > of that you get a way above average rate of hard drive failures. But > aside from all this you managed to recover multiple times. >=20 Incorrect.. I shipped the server around the world 18 months ago.. (Oct 2017= ).. before that the power problems... well Malta is legendary for them... = =20 This was the last to hit me before I moved back home to Australia after bein= g there for 8 years... =20 https://www.timesofmalta.com/articles/view/20170826/local/hundreds-of-househ= olds-without-power-after-fire-in-distribution-centre.656490 > ZFS is never claimed to be a get out of jail free card, but it did > survive in your case multiple times, I suggest tho if you value > redundancy, do not use RAIDZ but use Mirror instead. I dont know why > people keep persisting with raid 5/6 now days with drives as large as > they are. Could that be because at the time of building it, the largest drives were 4T= ... had the 6T drives been available to me I would have mirrored 6T drives i= nstead of zRAID2 ing 16x3T drives. >=20 > I have used ZFS since the days of FreeBSD 8.x and its resilience > compared to the likes of ext is astounding and especially compared to > UFS. I=E2=80=99m not disputing its resilience to errors in the file data, it is r= ather good, but when it comes to the metadata that=E2=80=99s when I have alw= ays had problems.. it=E2=80=99s ok until it isn=E2=80=99t, then it=E2=80=99s= lucky if you can get it back... and until now I=E2=80=99ve had that luck. >=20 > Before marking it down think how would UFS or ext have managed the > scenarios you presented in your blog. Well I have 2 servers with zfs, the rest are UFS or HPFS... the only other I= ssue I had was a (mirrored drive) with HPFS... it got corrupted where it (t= he FSCK like tools) couldn=E2=80=99t fix it... but the drive was still acce= ssible and the backups were on the zfs drives... (timemachines in zvols over= iscsi)... I didn=E2=80=99t need to go to timemachine (though I did check th= e data for consistency after =E2=80=9Crestore=E2=80=9D) .. I got new drives,= replaced then, mirrored them, then copied over everything except the OS by m= ounting one of the drives in an external caddy... solved the underlying =E2= =80=9Cunfixable=E2=80=9D error in the HPFS structures... >=20 > Also think about where you hosting your data with all your power > failures and the UPS equipment you utilise as well. Well I have insurance quotes for new UPSes that I=E2=80=99m waiting on repla= cement so that=E2=80=99s sorta mute... I could post the images of them here= if you like or don=E2=80=99t believe me? Seriously it is unusual I get it, but all my ZFS problems have been due to f= ailures whilst resilvering ... it=E2=80=99s always (over 8 years of running t= hese servers) resilvering tHat does it... it=E2=80=99ll be happily progress= ing and another drive fails, power goes out, kernel panic, etc... then the p= roblems start, and if it does it twice you better start praying. This is my= experience. Michelle >=20 >> On Mon, 29 Apr 2019 at 16:26, Michelle Sullivan <michelle@sorbs.net> wrot= e: >>=20 >> I know I'm not going to be popular for this, but I'll just drop it here >> anyhow. >>=20 >> http://www.michellesullivan.org/blog/1726 >>=20 >> Perhaps one should reconsider either: >>=20 >> 1. Looking at tools that may be able to recover corrupt ZFS metadata, or >> 2. Defaulting to non ZFS filesystems on install. >>=20 >> -- >> Michelle Sullivan >> http://www.mhix.org/ >>=20 >> _______________________________________________ >> 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"= > _______________________________________________ > 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"
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