On 13/01/11 15:30, Hugo Mills wrote:
> On Thu, Jan 13, 2011 at 03:23:30PM +0000, Chris Dennis wrote:
>> Hello folks
>>
>> I've come across a problem on a friend's computer.
>>
>> The computer is fairly old (see below), running Ubuntu 10.10, with /
>> on a 40GB IDE drive, and /home on a 120GB Maxtor SATA drive.
>>
>> It's /home that's the problem. It's on a single partition
>> /dev/sda1, formatted as ext4. I've run the Maxtor diagnostics on
>> the drive, and no problems were reported.
>>
>> Ubuntu wants to check the filing system on every boot. Running
>> 'fsck -f' manually (from Knoppix 6.2) gives:
>>
>> Block bitmap differences:<some number ranges, different each time>
>>
>> Sometimes it also offers to fix:
>>
>> Free blocks count wrong for group #<numbers that change each time>
>>
>> I choose to fix those problems, but they're still there next time.
>>
>> I've also run 'fsck -fc /dev/sda1' -- it didn't report any bad
>> blocks, and the other were still there.
>
> This smacks to me of a disk that's constantly remapping duff
> sectors into spares, and finding more duff sectors. Replace the
> hardware ASAP.
>
> [...]
>>
>> ran fsck again, and the errors have returned!
>>
>> Why would copying data into a filing system cause errors like that?
>
> Bad hardware.
>
> Hugo.
Thanks for your reply Hugo.
I'd have thought the same if the initial disk scan hadn't been OK.
So I did some more checks:
* older Maxtor diagnostics -- no errors.
* latest Seatools diagnostics -- no errors.
* SMART (via HDAT2 CD) -- only one error in lifetime of disk,
no reallocated sectors, no pending or uncorrectable errors.
* SMART extended offline test -- no errors.
Then I ran
mkfs.ext3 -c -c /dev/sda1
with full read-write checks for bad blocks -- it found none, and SMART
still reports no reallocated sectors.
fsck on the empty filing system was OK. Copied all the data back as
before (about 30GB), and fsck is still happy.
Note that I've now made the partition ext3 instead of ext4. Would that
make a difference? I did notice that when running fsck on the ext4
partition, the first 4 passes were almost instantaneous; only pass 5
'Checking group summary information' took a bit longer, and detected the
errors. With ext3, pass 1 takes much longer (i.e. 10 seconds instead of
less than 1).
Anyway, the data is all backed up, so I'll see how it goes for a while,
unless anyone can think of any other tests I can run on the drive.
cheers
Chris
--
Chris Dennis cgdennis@???
Fordingbridge, Hampshire, UK
