Date: Wed, 14 Dec 2016 12:05:55 -0700 From: Alan Somers <asomers@freebsd.org> To: Dirk-Willem van Gulik <dirkx@webweaving.org> Cc: Peter Jeremy <peter@rulingia.com>, FreeBSD Hackers <hackers@freebsd.org> Subject: Re: ZFS - directory entry Message-ID: <CAOtMX2gYa2iiAUeDjzmaakS%2BQ9_8fJ0SdSr4a8Bt9c=NNB4OsQ@mail.gmail.com> In-Reply-To: <68290275-9C8D-4ACC-9E29-B6A7805512FD@webweaving.org> References: <BEAC6EE9-C50F-4FB9-B215-D5A6691E2DD9@webweaving.org> <20161214185154.GT61036@server.rulingia.com> <68290275-9C8D-4ACC-9E29-B6A7805512FD@webweaving.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, Dec 14, 2016 at 12:01 PM, Dirk-Willem van Gulik <dirkx@webweaving.org> wrote: > >> On 14 Dec 2016, at 19:51, Peter Jeremy <peter@rulingia.com> wrote: >> >> On 2016-Dec-14 16:27:00 +0100, Dirk-Willem van Gulik <dirkx@webweaving.o= rg> wrote: >>> A rather odd directory entry (in /root, the home dir of root/toor) appe= ared on a bog standard FreeBSD 10.2 (p18) lightly loaded machine under ZFS = during/post a backup: >>> >>> $ ls -la /root | tail -q >>> ---------- 1 root wheel 9223372036854775807 Jan 1 1970 ?%+?kD?H??= ?x,?5?Dh;*s!?h???jw??????\h?:????????``?13?@?????OA????????Puux????<T]???R?= ?Qv?g???]??%?R? >>> >>> OS and ZFS is installed with a bog standard sysinstall. =E2=80=98SMART= =E2=80=99 nor smartd have reported anything. nothing in dmesg, syslog of bo= ot log. Any suggestions as how to debug or get to the root of this ? >>> >>> And in particular - what is a risk of a reboot (to get a kernel with de= bug, etc) causing the issue to =E2=80=98go away=E2=80=99 - and hence stoppi= ng the forensic ? >> >> Do you have ECC RAM? If not, it's possible this is an artifact of some = RAM >> corruption, rather than on-disk corruption. > > No ECC (simple 4x8 Gbyte sticks; nothing on L2 and L3 either). > >> I'm surprised by the slow scrub, though they are very slow disks. You m= ight >> like to use gstat or zpool iostat to see if one of the disks is slower t= han >> the others - indicating a possible problem with it. > > Perfectly balanced. Rocks steady last few hours according to per disk gra= phs. We=E2=80=99ll see how it goes before rebooting (and if it is indeed me= mory - that will I guess mask the issue until it appears again). > > Thanks, > > Dw If your system is mostly idle, then you can speedup scrub with the following sysctls: vfs.zfs.resilver_min_time_ms=3D5000 vfs.zfs.top_maxinflight=3D1024 # 1024 is appropriate for 8GB of ram. With more RAM, you can go higher. -Alan
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CAOtMX2gYa2iiAUeDjzmaakS%2BQ9_8fJ0SdSr4a8Bt9c=NNB4OsQ>