On Mon, 30 Jan 2012, Yasha Karant wrote:

> On 01/30/2012 03:35 PM, Dag Wieers wrote:
>
>>  I wonder:
>>
>>  - whether you were in fact using a journalling filesystem (because it
>>  should even recover from power failure like that when it is journalled)
>
> For the most part, for a number of reasons, we are sticking with ext2, with 
> -- in the case of my workstation -- fuse ntfs for MS Windows which is 
> required for particular unpleasantries.  We have not made a production change 
> to ext4, but are considering the transition.  We are attempting to get 
> detailed data on the reliability of the ext4 filesystem, how much overhead 
> (loss of data capacity) ext4 requires, and the performance change (loss?) 
> between ext2 and ext4.  Any detailed, preferably quantitative, comparisons on 
> production systems will be appreciated.

I wonder why you chose ext2 over ext3. The cause of all your troubles is 
because you did not opt for the journaling filesystem. And ext3 is 
nowadays a lot more tested and a safer option than ext2. Ext4 does not 
have the same maturity/reliability as ext3, but it is getting there.

You can find benchmarks on the net wrt. ext2 vs ext3 vs ext4. Comparisons 
based on production systems depends completely on workload and I/O 
patterns and do not necessarily translate back to your systems (at least 
not if the I/O patterns are not known).


>>  - what was mounted on /mnt/sysimage (as normally this is your
>>  root-filesystem during installation, not during runtime)
>
> I did a manual umount from the rescue running image, and verified with mount 
> that /mnt/sysimage was not mounted .  Nonetheless, when the production system 
> attempted to reboot, it reported that the /dev/sda5 was not cleanly 
> unmounted, and started automatic fsck.  This fsck failed, with the request 
> that I manually run fsck -- an operation I could not do as the root password 
> was not accepted, being truncated by the root password input procedure.

Ok, I now see what you mean. It is rather confusing to refer as the 
filesystem having problems is /mnt/sysimage, while that is not the 
location where it normally is mounted. If you would have mentioned it was 
your root filesystem, that would have been more clear.

BTW I am surprised you are not using LVM either. I find it very strange to 
see in this day and age a system still using mere partitions and ext2. 
This 2012, we left filesystem on partitions at least 2 major release 
(about 6 years) ago :)


> Do the above comments clear the fog?

A bit.

-- 
-- dag wieers, [log in to unmask], http://dag.wieers.com/
-- dagit linux solutions, [log in to unmask], http://dagit.net/

[Any errors in spelling, tact or fact are transmission errors]