Mainpage
Searchform
History
Versions
Categories
Contents
Kernel: Version 2.2
Data corruption can of course show up in a number of ways. The best way to identify the problem is of course via standard elimination and troubleshooting measures. The following are some example indications:
* - please note these can be caused by other hardware problems as well, such as memory, processor, cache problems.
A simple, but decent test, involves copying large amounts of data from or to the IDE device, and then using diff to see if the data compares to be the same. Ex.: Copying a few hundred megabytes from a CDROM to a hard drive
cp -r /cdrom/something /tmp/something diff -r /cdrom/something /tmp/somethingIf any differences are encountered, you are definitely seeing data corruption.
A variety of problems can cause data corruption in the IDE communication stream. These include:
A variety of steps are possible, and multiple may be necessary. In discussion of IDE modes, you may want to refer to the brief mode listing below, or perhaps refer to a more detailed online discussion of IDE modes, such as this one or this one.
Ruling out such problems with cabling will increase reliability, and allow for faster transfers. It is worth it.
Be certain that the documentation for your devices state they can support the transfer rates you have selected. If you have problems at this level, reduce the rates further until the problem is alleviated. Remember, the data errors may be happening in the controller or the cable.
To reach a prompt during a Yast-1 installation in 6.3, or in SuSE installations prior to 6.3, press ALT-F2 after starting YaST. You may return to Yast with they keystroke ALT-F1.
To reach a prompt during a Yast-2 installation, press CTRL-ALT-F2 after Yast-2 starts. You may return to Yast-2 with the keystroke ALT-F7.
A good first step in reducing IDE problems, is to disable DMA. This can be done with the command hdparm -d0 /dev/<device>. For example, if your CDROM is set to master on the secondary controller, use the command
hdparm -d0 /dev/hdcIf this is not sufficient, you may want to reduce the transfer rates. hdparm -XNN /dev/device will set the transfer mode. Here is what values are valid for NN:
08 - PIO mode 0 09 - PIO mode 1 10 - PIO mode 2 11 - PIO mode 3 12 - PIO mode 4 13 - PIO mode 5Sometimes it is best to get a bit paranoid and set the device to the absolute basics, of course replacing /dev/hdc with your IDE device in question.
hdparm -d0 /dev/hdc hdparm -X08 /dev/hdcThis of course will slow the device down somewhat, but if it stops the symptoms, you've located the problem.
The following is a listing of modes from most reliable to most rapid:
PIO (programmed I/O) Mode 0 - this may not be available in all intefaces DMA Mode 0 PIO Mode 1 PIO Mode 2 PIO Mode 3 DMA Mode 1 PIO Mode 4 DMA Mode 2 PIO Mode 5 DMA Mode 3 (also known as DMA 33, or UDMA) DMA-66All other things equal, the PIO modes tend to be better supported than the DMA modes.
Keywords: DATA ERRORS, DATA CORRUPTION, IDE CABLE, PIO
Categories:
IDE
, Installation
Mainpage
Searchform
History
Versions
Categories
Contents