[Elphel-support] Testing HDD Writespeed

[Sebastian Pichelhofer]

No, I am not experiencing any problems (yet).

I just added a video datarate indicator to ElphelVision and the next
logical step for me is to have a way of determining if the connected
HDD is able to write the data at this speed.

Regards Sebastian

On Sun, Sep 26, 2010 at 18:56, Andrey Filippov <andrey at elphel.com> wrote:
> Sebastian,
>
> Are you getting problems in the middle of the file or when the camera starts
> a new one? Our experience (but we used it with huge "triplets" for Eyesis
> show that most problems are when camera operating system creates a new file.
> Oleg wrote some profiling tools that watches the buffer, there is also an
> application that dynamically adjusts the compression quality to keep buffer
> from being overrun.
>
> If you have similar problems you may want to decrease the partition sizes
> and/or files per directory - see if that helps.
>
> Andrey
>
> On Sun, Sep 26, 2010 at 10:14 AM, Sebastian Pichelhofer
> <sebastian.pichelhofer at gmail.com> wrote:
>>
>> Does anyone know a reliable way of testing a HDDs write speed over the
>> entire free space area (faster outer regions to slower inner regions)
>> without having to fill up the entire disk which could take quite a
>> while for big disks?
>> Maybe write 3x1GB blocks (outer area, center area, inner area)?
>>
>> Most likely this will only work with a completely empty disk
>> (formating before testing), right?
>>
>> Optimally this would be doable with dd or other tools that are
>> available in the cameras...
>>
>> Regards Sebastian
>
>