Slow disk I/O - was Re: Seeking Help [Ubuntu Bug??]

[Geoff at thebakershome.net]

> On 26 January 2013 20:10,  <geoff at thebakershome.net> wrote:
>> I took a couple of days to backup all of my data and repartition my
>> drives. I then installed 12.04 onto my 1 TB platter drive. It took only
>> 12
>> minutes (far faster than 12.10 on the SSD which was 6 hours).
>>
>> I rebooted into 12.04 and did an "apt-get"
>>
>> Fetched 1,001 kB in 4s (231 kB/s)
>> Reading package lists... Done
>>
>> real    0m6.918s
>> user    0m1.824s
>> sys     0m0.128s
>>
>>
>> It appears to me that there is a bug in Ubuntu 12.10 that was not
>> present
>> in 12.04.
>>
>> That same command in 12.10 takes 20 minutes.
>>
>> Anyone have any advice about what I should do next?
>
> Plug in the SSD as well, but still boot 12.04 on the platter drive.
> Then go to the SSD and exercise it with stuff that took a long time
> before, assuming there was something other than apt-get that was slow.
>  If necessary boot back on the SSD and find something else that is
> slow first.  Obviously compare the times.

There is no point. The platter drives are slow in 12.10 (compiling test
done on these)

Platter and ssd are slow on this computer with 12.10 but fast with 12.04.
Same drives in computer with older hardware and both Ubuntu revisions work
great.

Either there is a bug in Ubuntu or the motherboard has an error reporting
information that is ignored by 12.04, but impacts 12.10.


>
> Colin
>
>>
>> I have 12.10 all setup the way I like, is there an easy way to move all
>> that data to 12.04?
>>
>>
>>> I do not know for sure. I get good benchmark sppeds in 12.10 as well.
>>> The
>>> problem is when dealing with lots of small files (apt-get update,
>>> compiling many files, etc).
>>>
>>> I do not know how to properly test this from the live 12.04 disk.
>>>
>>> I moved some data around on the hard drives overnight. Tonight I plan
>>> to
>>> install 12.04 onto one of the platter drives. This should allow me to
>>> to a
>>> proper test of the same commands (apt-get update) and better compare
>>> the
>>> performance.
>>>
>>>>> I booted the 12.04 Ubuntu live disc and recorded some data.
>>>>>
>>>>> Disk Utility:
>>>>>   All drives are detected as connected via SATA
>>>>>     SSD Benchmark Results:
>>>>>       Min Read Rate: 556.4 Mb/s
>>>>>       Max Read Rate: 565.6 Mb/s
>>>>>       Average Read Rate: 564.0 Mb/s
>>>>>       Average Access Time: 0.1 ms
>>>>
>>>> Those are excellent results. So, are you saying the main issue is with
>>>> the
>>>> version of Ubuntu? That 12.04 works well, and 12.10 does not?
>>>>
>>>>
>>>>
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>>>
>>>
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>>
>>
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