CentOS - Mar 2017 - CentOS-6.8 fsck report Maximal Count

We have a remote warm standby system running CentOS-6.8 as a KVM
system with multiple guests.  One of the guests began reporting an
error when running aide.

Caught SIGBUS/SEGV while mmapping. File was truncated while aide was
running?
Caught SIGBUS/SEGV. Exiting

The /var/log/messages file contained this:
Mar  9 09:14:13 inet12 kernel: end_request: I/O error, dev vda, sector
14539264
Mar  9 09:14:31 inet12 kernel: end_request: I/O error, dev vda, sector
14539296
Mar  9 09:14:48 inet12 kernel: end_request: I/O error, dev vda, sector
14539296

df
Filesystem           1K-blocks    Used Available Use% Mounted on
/dev/mapper/vg_inet02-lv_root
                       7932336 2262672   5260064  31% /
tmpfs                   961044       0    961044   0% /dev/shm
/dev/vda1               487652  139473    322579  31% /boot
. . .


This indicated that a bad sector on the underlying disk system might
be the source of the problem.  The guests were all shutdown, a
/forcefsck file was created on the host system, and the host system
remotely restarted.

However, this action did not remove the error.  The host system log
files had this to say about fsck:

/var/log/messages:Mar  9 08:34:48 vhost03 kernel: EXT4-fs (dm-6):
warning: maximal mount count reached, running e2fsck is recommended

in /dev I see this:
brw-rw----. 1 root disk    253,   6 Mar  9 08:34 dm-6

But, this device has nothing whatsoever to do with the kvm guests:

ll /dev/vg_vhost03/ | grep dm-6
lrwxrwxrwx. 1 root root 7 Mar  9 08:34 lv_centos_repos -> ../dm-6

Rather this is an lv devoted to holding CentOS ISOs:

/dev/mapper/vg_vhost03-lv_centos_repos
                     101016992 77160124  18718848  81% /var/data/centos

So, my questions are:

1. How do I fix the problem with the guest system that Aide is
stumbling over?

2. How do I get the fsck issue with dm-6 resolved?


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James B. Byrne                mailto:ByrneJB at Harte-Lyne.ca
Harte & Lyne Limited          http://www.harte-lyne.ca
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On Thu, 9 Mar 2017, James B. Byrne wrote:
> This indicated that a bad sector on the underlying disk system might
> be the source of the problem.  The guests were all shutdown, a
> /forcefsck file was created on the host system, and the host system
> remotely restarted.
fsck's not good at finding disk errors, it finds filesystem errors.

If it was a real disk issue, you'd expect matching errors in the host logs.
Did you?
> /var/log/messages:Mar  9 08:34:48 vhost03 kernel: EXT4-fs (dm-6):
> warning: maximal mount count reached, running e2fsck is recommended
Unmount it and run fsck on it, and that message would go away.  But I'd not
worry about that one.

jh