[vdr] Re: Disk performance (was: vdr - some general questions)

[Axel Gruber <axelgruber3@gmx.de>]

> The HD is a Maxtor 4D080H4 80 GB IDE. I know it's not the fastest but I
> thought some DVB-Streams would be no problem for any modern HD.
> How can I check if the HD is the problem? As I mentioned earlier I have
> also often digital artefacts both in picture and sound.

> Is it enough to switch DMA on (hdparm says it *is* on) or should I use a
> special DMA-Mode? I know different HDs and controller have different DMA
> features - is this configured automatically? I think default should be
> the fastest possible.

I have put DMA on and 32Bit access.

Here in only have Maxtor HDīs - they are cheap, big - but not very fast.
Here i can record 4 Streamd from 4 DVB-CArdīs at same time without problems.

I only have  Problem when i record 3 Streams and make a Playback of a Recording
at the same time.

But this depend on what HD does vdr use at this moment - VDR only looks on wich
HD is the most space at the moment and the he only record on this hd -

For example: you have 4 HDīs with 70% filled each - and you install a 5. hd
Vdr only will record to the 5. HD till it reach 70% then VDR look again to other HDīs.

So sometimes i have Problems (when VDR record all to the same HD) and i make a Timeshifting 
from this hd  - this is too much for it :-)

A easy solution for this would be a soft-Raid - so the Soft-RAID will connect 5 Devices
to one big device so you donīt have any problem to overload one single disk.


The Problem with a SOFTRAID (please correct me if iīm wrong)  is that is not simple to
easy add a aditional device to the RAID so you have delete it all and create a new RAID (as i know)

But back to your question: Yes - a simple maxtor 80GB device is enough for 3 Simultan Recording or 2 Recordings
and one Playback. - No Problem at all.

And yes - DMA sould be ON !



You can check hd-Performance with "bonnie" - but be sure to set a big Check-File sice.

CU

Axel