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On Tue, Nov 10, 2015 at 12:32 AM, Mike Gilbert <floppym@g.o> wrote: |
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> On Mon, Nov 9, 2015 at 2:36 PM, Jarry <mr.jarry@×××××.com> wrote: |
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>> On 08-Nov-15 17:58, Mike Gilbert wrote: |
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>>> On Fri, Nov 6, 2015 at 12:19 PM, Jarry <mr.jarry@×××××.com> wrote: |
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>>>> |
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>>>> I noted one strange thing today: It seems one of my servers lost "/"! |
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>>>> |
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>>>> vs5-dns ~ # df |
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>>>> Filesystem 1K-blocks Used Available Use% Mounted on |
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>>>> /var/log/named 10138552 2223148 7377344 24% /chroot/dns/var/log/named |
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>>>> tmpfs 308196 420 307776 1% /run |
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>>>> dev 10240 0 10240 0% /dev |
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>>>> shm 1540968 0 1540968 0% /dev/shm |
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>>>> cgroup_root 10240 0 10240 0% /sys/fs/cgroup |
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>>>> none 1048576 0 1048576 0% /var/tmp/portage |
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>>> |
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>>> Is your /etc/mtab a regular file, or is it a symlink to |
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>>> /proc/self/mounts? The latter is recommended. |
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>> |
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>> It is regular file. I never changed it... |
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>> |
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>> vs5-dns ~ # ls -l /etc/mtab |
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>> -rw-r--r-- 1 root root 908 Nov 9 19:14 /etc/mtab |
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>> |
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>>> Anyway, please have a look at the contents of /etc/mtab, |
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>>> /proc/self/mounts, and proc/self/mountinfo while named is running and |
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>>> when it is stopped. If you pastebin them we can take a look for key |
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>>> differences. |
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>> |
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>> With bind running: |
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>> http://pastebin.com/wkTW6xAY |
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>> |
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>> without bind: |
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>> http://pastebin.com/JG5FPNDW |
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>> |
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>> While I can see some differences there, I still do not understand |
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>> why is "/" missing in "df" output. BTW I can not proove it, but this |
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>> was not the case all the time. At least when I was tuning monitoring |
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>> software, I'm pretty sure "/" was there... |
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> |
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> It may be a bug. |
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> |
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> Can you try replacing /etc/mtab with a symlink to /proc/self/mounts to |
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> see if it makes any difference? That triggers different code paths in |
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> several programs. |
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|
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From the OP's pastebin: |
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|
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vs5-dns ~ # more /etc/mtab |
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/dev/sda2 / ext4 rw,noatime,data=ordered 0 0 |
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/etc/bind /chroot/dns/etc/bind none rw,bind 0 0 |
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/var/bind /chroot/dns/var/bind none rw,bind 0 0 |
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/var/log/named /chroot/dns/var/log/named none rw,bind 0 0 |
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|
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vs5-dns ~ # more /proc/self/mounts |
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/dev/sda2 / ext4 rw,noatime,data=ordered 0 0 |
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/dev/sda2 /chroot/dns/etc/bind ext4 rw,noatime,data=ordered 0 0 |
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/dev/sda2 /chroot/dns/var/bind ext4 rw,noatime,data=ordered 0 0 |
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/dev/sda2 /chroot/dns/var/log/named ext4 rw,noatime,data=ordered 0 0 |
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|
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There was a blog post a few years ago by the util-linux maintainer in |
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which he was pushing for users to symlink "/etc/mtab" to |
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"/proc/self/mounts" and he was explaining that having "bind" as a |
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property in mtab doesn't make sense because you could unmount the |
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"bound-to" mount and the "bound" mount would still show "bind" as a |
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property. |
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|
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Is "/" shown when you run "df -a"? If it's shown, then there's a bug |
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in coreutils (as long as they accept a bug on a system where mtab |
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isn't a symlink) because, AFAIR, "df" should show the mount with the |
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shortest mount path if a filesystem's mounted more than once. |
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