You haven't said whether your root partition actually is full.  Once 
it's mounted, either via the Live CD or by booting in "single" mode, the 
"df" command will show if it's 100% full.  If it is, deleting 
non-essential files should help, provided they are on the root partition, 
and not on some other partition that's mounted later.  If, for example, 
/home is a separate partition mounted on /, clearing data from it won't 
help.  Good places to look for large amounts of non-essential data are in 
/tmp and /var/log, and you may have installed your system with /tmp and 
/var simply subdirectories, rather than separate partitions.

Steven Yellin

On Sat, 8 Sep 2012, zxq9 wrote:

> On 09/08/2012 06:49 AM, Dirk Brandherm wrote:
>> Hi there,
>> 
>> I hope that someone here will be able to help me with the following. I
>> 
>> recently tried to install a Retrospect backup client to my Scientific Lin
>> ux
>> 6.1 system. The installation hung, and the next time I tried to boot the
>> 
>> system, it refused to start and hung at this point:
>> 
>> 
>> Mounting local filesystems: error writing /etc/mtab.tmp: No space left on
>> 
>> device
>> error writing /etc/mtab.tmp: No space left on device
>> error writing /etc/mtab.tmp: No space left on device
>> mount: devpts already mounted or /dev/pts busy
>> mount: sysfs already mounted or /sys busy [FAILED]
>> Enabling local filesystem quotas: [OK]
>> Enabling /etc/fstab swaps: [OK]
>> Entering non interactive startup
>> Calling the system activity data collector (sadc):
>> Starting monitoring for VG vg_gapqub01: 3 logical volume(s) in volume
>> group“vg_gapqub01" monitored  [ok]
>> dkms: running auto installation service for kernel 2.6.32-279.5.1el6.x86_
>> 64
>> 
>> And at that point the boot routine stops. I have tried to reboot several
>> 
>> times. The result is always the same. The boot process never proceeds
>> beyond this point.
>> 
>> I have no clue what happened here. The hard disc certainly should not be
>> 
>> full at this stage. I even booted Scientific Linux from the Live CD to fr
>> ee
>> some space deleting a number of old files, but this had no effect. I am a
>> t
>> a loss here. Any help would be greatly appreciated.
>
> Just off the top of my head...
> Did the Retrospect installation procedure alter /etc/fstab ? It may be useful 
> to boot from a liveCD/USB and check what is in /etc/fstab . If the installer 
> did touch /etc/fstab, check if the installer backed it up (probably something 
> like /etc/fstab.bak or /etc/fstab.retrospect.bak) and diff the two to see 
> what changed.
>