Talk:HOWTO Use hdparm to improve IDE device performance
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Write-caching enabled may eat journaling filesystems! Use it at your own risk.
A note on kernel configs for Intel 848P (ICH5) motherboards, I suspect this option must be enabled for most intel motherboards anyways.
You have to enable Device Drivers->ATA/ATAPI/MFM/RLL support->Intel PIIXn chipsets support in your kernel (compiled not module) in order NOT to get the "Operation not permitted" message in hdparm.
--- The above is probably because that user has a Intel PIIXn controller chip, and therefore not everyone needs that (ie the support needed is different depending on the hardware.
I don't get it... In a part in this document it is explained why it is not neccesary to set -m(x) on newer UDMA drives. Later on in this howto there is an example configuration file in which a UDMA-5 hdd gets the -m16 option. Also, setting -A1 does not work for optical drives.
On the note about RAID, it would be nice if some more info was given here. I'm under the understanding that DMA should be off, but are there any other options that may be useful? Obviously if you're runnning a RAID then disk performance is something that probably matters (you do cool things hard disks my guess is you want em running to their fullest extent versus joe-user who hardly realizes there is a hard disk). So can we get some answers on how this affects us RAID users? e.g. if we enable DMA should we expect catastrophic disk failure? can we expect better performance before the cataclysm? are there other modes that can be set with hdparm that might improve RAID performance without calling the four horsemen of the apocalypse?
[edit] hdparm -m
On my system is MacMultSect=128. If i try to make : hdparm -m128 /dev/hda I get the folowing error:
-m: bad/missing multmode-count value (0..64)
It seems that i have just use -m1 to set MultSect on and than the MaxMultSect is used. Perhaps it should be added to the article
