On Tuesday January 16 09:45, Darrell May wrote:
> Michael, don't think of it as a tape drive. How would you turn DMAon for a
> hard drive? Same should apply as they are all just /dev/hdx where x =
>
> hda = primary master
> hdb = primary slave
> hdc = secondary master
> hdd = secondary slave
>
> Regards,
>
> Darrell
Darrell,
ok, give it a try. At least for CDROM drives it works. But CDROM are random
access devices. The instructions below only relate to _hard_drives_.
Even if it works I don't expect a significant speed up, since the data transfer
rates of tape drive in principle are low. But you can expect a decrease in CPU load.
If it works for your IDE tape and you want DMA mode to persist, add the appropriate
commmand somewhere in /etc/rc.d/rc.sysinit. Good luck!
BTW, what type of IDE tape drive you are using (costs, media type+costs, capacity)?
Michael
(I decided to post to the list, since it could be useful to others)
--- setting DMA mode for IDE hard disks ---
hdparm -d1 /dev/hda
enables DMA for the first IDE disk
See "man hdparm" for more options. But be careful with -X34 or -X66.
Usually these have no effect, but you could end up with a corrupted
filesystem.
If you want to use DMA permanently, edit /etc/sysconfig/hardisks and
set USE_DMA=1.
Do not use the hdparm -tT for benchmarking. The result are not very reliable.
Better use bonnie++ or something similar.
To be found at http://www.coker.com.au/bonnie++
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