HDPARM - IDE CONFIGURATOR

From: Peck Dickens <peck_d@bellsouth.net>


A friend of mine who uses redhat did the following to his system that has IDE drives installed. I have done it once to a system I have (p100) with IDE in it. However, it's probably been a year so since I did it... Anyway the following does greatly improve performance. Just remember: If you choose to do this it is at your own risk and I don't want to hear about it if your system gets trashed.

How to do it:

You must be logged in as root to do this. Also, make sure no one else is using the hard drive (i.e. don't do this on a production file server in the middle of a work day.) do *not* not try this on SCSI hard drives. You have been warned.

Enter the following command at the # to check whether 32-bit I/O and DMA are turned on.

hdparm -c -d /dev/hda

On a new install, they are probably set to 0 which means they're turned off. Test the performance of the hard drive to get a benchmark for later comparison. Enter the following command at the # and give it about 15 to 30 seconds to complete.

hdparm -t /dev/hda

Now, you should see something that looks like the following:

/dev/hda
Tming buffered disk reads: 64 MB in 21.12 seconds = 3.03 MB/sec

Turn on DMA and 32-bit access and see if you get better performance. Enter the following command at the # :

hdparm -c 1 -d 1 /dev/hda

Now run the test again.

hdparm -t /dev/hda

Here are what new results will sort-of look like:

/dev/hda
Timing buffered disk reads: 64 MB in 4.86 seconds = 13.17 MB/sec

About a 400% improvement. Make sure your system will use the new settings after a rebooting. Enter the following command at the # to save the new setting after a soft reboot:

hdparm -k 1 /dev/hda

To save these settings through a hard reboot, you must add a line to a start-up scripts. Add the following line to the end of the file /etc/rc.d/rc.local:

hdparm -c 1 -d 1 -k 1 /dev/hda

In this example, you are changing the settings for the first hard drive your system (hda). If you have more than one IDE hard drive, you should change the setting for it as well.


Be careful. *VERY* careful.

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Here is the Oreilly Article:

http://linux.oreillynet.com/pub/a/linux/2000/06/29/hdparm.html

Here are the -X parameters:

IDE modes for hdparm -X parameters:

PIO mode
0 -X08 3.3MB/sec
1 -X09 5.2MB/sec
2 -X10 8.3MB/sec NEC PC-98*1
3 -X11 11.1MB/sec
4 -X12 16.7MB/sec

Single word DMA mode
0 2.1MB/sec
1 4.2MB/sec
2 8.3MB/sec

Multiword DMA mode
0 -X32 4.2MB/sec
1 -X33 13.3MB/sec
2 -X34 16.6MB/sec

Ultra DMA mode
0
1
2 -X66 33MB/sec UDMA33
3
4 -X68 66MB/sec UDMA66

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