[Dovecot] Howto add another disk storage

Stan Hoeppner stan at hardwarefreak.com
Mon Jul 9 02:59:42 EEST 2012


On 7/8/2012 5:16 PM, Matthias-Christian Ott wrote:
> On 2012-07-08 23:29, Stan Hoeppner wrote:
>> On 7/8/2012 8:27 AM, Patrick Domack wrote:
>>>
>>> Quoting Wojciech Puchar <wojtek at wojtek.tensor.gdynia.pl>:
>>>
>>>>> I think there are optimal situations where any configuration looks
>>>>> good . . How often can a real-world disk actually deliver the 6Gbs
>>>>> when only a minority of disk reads are long sequential runs on the
>>>>> platters?
>>>> none of hard drives can saturate 1.5Gb/s
>>>
>>> There are many disks out that do 150-200MB/sec, easily exceeding 1.5gb/s
>>> speeds.
>>
>> There are a few SAS drives that can saturate a 150MB/s link, such as the
>> Seagate Cheetah 15k.7, which can sustain 204MB/s streaming read on the
>> outer tracks.
>>
>> But, again, streaming rate is irrelevant to mail storage.  What matters
>> is random seek latency.  And the faster the spindle, the lower the
>> latency.  Thus 15k Seagate SAS drives are excellent candidates for mail
>> store duty, as are any 10k or 15k drives.
> 
> This is simply not true. SATA SSDs (~0,66 €/GB) are as expensive as the
> 15k Seagate SAS HDDs (0,63 €/GB), but definitely faster.

First, this sub discussion in this thread has been dealing strictly with
mechanical storage, and that was intentional.

Now you've injected solid state storage, and in the process you first
disagreed with my statement, then agreed with it.  Apparently you didn't
realize you did so.  Would you please clarify what I stated that is
"simply not true"?  You comment WRT SSD doesn't prove anything I said to
be untrue.  Quite the contrary, you reinforced my statements.

-- 
Stan



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