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

[geoff at thebakershome.net]

> On 26 January 2013 21:25,  <Geoff at thebakershome.net> wrote:
>>> On 26 January 2013 20:10,  <geoff at thebakershome.net> wrote:
>>> ...
>>> 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.
>
> You say there is no point doing the experiment, but then you provide
> the results of the experiment (saying the ssd is fast with 12.04 on
> the same mother board that we have been talking about).  So I am
> confused.
>
> Colin

There is no point in the experiment because the data has been collected.

1. SSD and Platter drives are slow with high I/O on 12.10 (20 minutes to
finish apt-get update after download is finished)

2. SSD and Platter drives are fast with high I/O on 12.04 (finishes in
seconds)

3. On old hardware the same drives are fast with both 12.04 and 12.10

Does that help

>
>>
>> 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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