Unpredictable drive errors

Posted on May 12, 2011 by admin.
Categories: Linux tips and tricks, Windows Tips.

from my favorite disk imaging program support website, a very helpful guide to fixing disk read or write errors due to glitchy items like bad IDE cables: http://www.terabyteunlimited.com/kb/article.php?id=152

Image Validation Fails with Image Stream Corrupt or Byte-for-Byte Validation Failure Message

This problem can be caused by overclocking, overheating, a hardware problem, or a BIOS or firmware bug or configuration issue.

To determine if the mainboard, memory, or CPU is at fault:

  • Download and run either the Microsoft Windows Memory Diagnostic or memtest86 (or try both of them).
    • If you use the Windows Memory Diagnostic, run the extended tests overnight.
    • If you use memtest86, run all seven of the default tests and allow it to run overnight.

If the memory diagnostic does not report any errors, check the following:

  • Run chkdsk /f on both the source drive and the drive holding the backup image. Important: Only run chkdsk if the memory diagnostic did not report any errors. Running chkdsk on a system with bad memory can result in data corruption.

    Start a Command Prompt and then run chkdsk x: /f where x: is the drive to check.
    For example: chkdsk c: /f

    Note: If running Windows Vista or Windows 7, you must run chkdsk from an Administrator Command Prompt.

  • If the problem is occurring when saving images to an optical drive, try burning at a slower speed and/or updating the drive’s firmware, if possible. Also, please refer to the article Message “Unable to read from file” when Performing Image Validation or Restore, if applicable.
  • If you are overclocking, revert your settings to the defaults and determine if the problem goes away.
  • If you are using a non-standard, third-party system BIOS or device firmware, switch to the latest final version of the manufacturer-supported BIOS or firmware, reset all BIOS settings to the defaults (referred to as a “clearing the CMOS” procedure by some mainboard manufacturers) and determine if the problem goes away.
  • If you have recently flashed to a different version of your system BIOS or the firmware of the controller to which your drive is connected (even if you the version used is a manufacturer-supported version), try reverting to the BIOS or firmware version you were using before (or the latest version) and determine if the problem goes away.
  • If you are having the problem with an IDE drive and you are using an IDE cable that is greater than 18 inches in length, replace the cable with one that is 18 inches or shorter in length.
  • Switch to an 80-conductor IDE cable.
  • If you have an IDE drive that is set to master (and/or is the only device on the IDE cable) ensure that it is connected to the end of the IDE cable.
  • If you are using a USB drive, please see the following KB article:
    Troubleshooting USB Drive Connection and Performance Issues



  • Ensure that your system, including any applicable drives, are not running at temperatures that exceed the manufacturer specifications.  If any temperatures are high, addtional case fans may be needed.
  • The drive may have weak sectors.  Try a thorough test with a utility provided by the drive manufacturer, with SpinRite, or with a similar utility.


If none of the above helps, the problem may be due to weak sectors on the drive surface. If the issue you are having involves a hard drive, download and run the hard drive manufacturer’s diagnostic utility or a third-party utility designed to scan and repair hard disk surfaces. Below are links to some major hard drive manufacturer’s home pages:

ExcelStor
Fujitsu
Hitachi
Seagate/Maxtor
Samsung
Seagate
Sony
Toshiba
Western Digital

If you still have not narrowed down the problem, try adjusting the system BIOS parameters below, for the drive(s) with which you are experiencing the problem. These settings, if available, are typically found under “Integrated Peripherals” or in the “Drive Configuration” section.

  • Disable “Block mode”
  • Disable “32-bit access”
  • Switch to a different PIO mode
  • Switch to a lower UDMA mode, if using UDMA

Linux root password for live session

Posted on May 9, 2011 by admin.
Categories: Linux tips and tricks.

When there is no root password for a live session in linux you can type:

sudo passwd root

Then enter a new unix password

Then type su as normal to gain root access.
su

Another way: in Debian there is no root user only type
#sudo su -

If you need root access in Ubuntu then it’s different, there is no actual root, with Ubuntu you need to do sudo, this line shows you how.