fsck / GEOM / Editing files in mirror partitions separately

[Stephan Wehner]

Hello there,

I have a FreeBSD 10.0-RELEASE-p7 system with system specifics:

$ mount
/dev/mirror/gm0s1a on / (ufs, local, journaled soft-updates)
devfs on /dev (devfs, local, multilabel)
/dev/mirror/gm0s1b on /home (ufs, local, journaled soft-updates)
procfs on /proc (procfs, local)

$ gmirror status
      Name    Status  Components
mirror/gm0  COMPLETE  ada0 (ACTIVE)
                      ada1 (ACTIVE)

$ gpart show
=>        63  3907029104  mirror/gm0  MBR  (1.8T)
          63  3907029042           1  freebsd  [active]  (1.8T)
  3907029105          62              - free -  (31K)

=>         0  3907029042  mirror/gm0s1  BSD  (1.8T)
           0  2456848384             1  freebsd-ufs  (1.1T)
  2456848384  1433600000             2  freebsd-ufs  (684G)
 3890448384    16580658             4  freebsd-swap  (7.9G)

Computer was rebooted by simply turning it off. On reboot, I got
message "error aborting boot enter full pathname or shell or return
for /bin/sh"

First question: Is it normal that the filesystem will not survive a
power loss, so that manual intervention is needed?
I thought UFS would be more robust.

Now I did something that may have been a bad idea.

I ran fsck on both partitions of the mirror separately, I think they
were called ad4s1 and ad6s1. For both it reported some problems to
fix, and I did Y until they were declared "CLEAN."

Then I mounted each partition separately, and made the same changes to
a single text file (the file was identical in each partition).

Then rebooted, and now the system is running fine.

Second question. Is that mirror in good shape? Is there a way to test?

Third question. Does one even run fsck on partitions that are then
controlled by geom?

This shows in dmesg:

GEOM_MIRROR: Device mirror/gm0 launched (1/2).
GEOM_MIRROR: Device gm0: rebuilding provider ada0.
GEOM_MIRROR: Device gm0: rebuilding provider ada0 finished.
GEOM_MIRROR: Device mirror/gm0 launched (2/2).

Thanks,

Stephan