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HardDrives

Page history last edited by Alexander Gunkel 10 mos ago

Advanced Hard Drive Techniques

 

 

Contents:

 

  1. Imaging
  2. Back-Ups
  3. Data Recovery
    1. Boot Disks
  4. Other Tools
  5. References
    1. File Systems
    2. The Partition Table

 

 

Disk Imaging

 

http://www.partimage.org/Main_Page - Cool GPL disk imaging. use via SystemRescueCD

Clonezilla.orgAn open source solution similar to ghost, with a multicast server solution and a boot disk solution.

g4l - ghost for linux

 

Seagate offers a number of tools for download:

http://www.seagate.com/www/en-us/support/downloads/

 

DiskWizard Imaging Software manual
SeaTools DST diagnostic tool manual
MaxBlast Imaging Software manual
PowerMax

 

Imaging Methods:

 

  1. Optical Disks
  2. Network
    1. Boot Disk
    2. PXE
  3. Hosted Imaging
    1. Drive-To-Drive
    2. Image-To-Drive

 

 

Back-Ups

 

Desktops, Abstract:

 

1) Image (New with every software install, OS update)

2) Removable Drive or Server, with script, user directories, other data directories. Run by user or scheduled.

 

 

Servers, Abstract

1) Image (New with every software install, OS update)

2) (Nightly/Weekly live images, if possible.)

3) Nightly data dumps to (Tape/Other Server/Removable Drive)

 

Windows, Desktop

 

Image

 

Removable Drive: Autorun on mount or schedule script as Scheduled Task (Control Panel -> Scheduled Tasks)

 

 

For Autorun, create these three files and put in root of removable drive:

 

autorun.inf

 

[autorun]

ICON=custom.ICO

open=backup.bat

shellexecute=backup.bat

label=WD Backup Drive

action=Backup your data

 

backup.bat

@echo OFF

echo.

echo This script will back up your user folder to the external drive.

echo %USERPROFILE% will be backed up to

echo \backup\

echo This process copies new and updated files only.

echo Close this window if you don't want to begin backup or

pause

echo Backing up

echo ON

xcopy "%USERPROFILE%" "\backup\" /D /E /F /H /C

 

custom.ICO

This can be any .ICO icon file you think cool. This makes your backup look more pro than the generic icon windows would use.

 

If you want to run as scheduled task, just schedule the backup.bat according to your needs and make sure the removable drive is connected and mounted.

 

 

MacOS X

 

Disk Utility to make images.

Applescript (or other *nix scripting language) for backups.

 

 

 

Hard Drive Data Recovery

 

See dedicated Page: Hard Drive Data Recovery

 

 

 

http://www.bootdisk.com/

http://www.freebyte.com/filediskutils/

http://www.winappslist.com/utilities/disk_utilities1.htm

Test Disk -- Great for damaged partition tables and other ills.

http://support.microsoft.com/kb/315265

http://www.networkclue.com/os/Windows/commands/

http://labmice.techtarget.com/windowsxp/DiskMgmt/tools.htm

http://www.linux-ntfs.org/doku.php

http://www.ntfs-3g.org/

http://dcfldd.sourceforge.net/

http://en.wikipedia.org/wiki/Data_recovery

Sleuth Kit

Power Data Recovery

Foremost - Data Carving

 

Boot Disks

 

http://www.sysresccd.org/Main_Page - Linux based boot disk

http://www.nu2.nu/pebuilder/ BartPE builder

http://www.ubcd4win.com/ Ultimate Boot CD For Windows

http://www.ultimatebootcd.com/ Ultimate Boot CD

 

 

  1. chkdsk volume: /r (/f or /x)

  2. testdisk (make repairs, copy data)

  3. chkdsk volume: /r (/f or /x)

  4. testdisk (copy data, again.)

 

Other Tools

 

JkDefrag - A GPL disk defrag for Windows.

 

 

References

 

NTFS 

FAT, FAT16 & FAT32

WinFS

MS guide to using chkdsk

 

 

The Partition Table

 

From http://www.cgsecurity.org/wiki/Intel_Partition_Table:

 

How is the Partition Table written ?

 

CHS (Cylinder, Head, Sector) values are limited by a set number of bits for each value in the 16-byte partition table entries to: 1023,254,63. So LBA and CHS values can't be equal for HD bigger than 8GB.

 

There are two ways to store the CHS value:

first way

convert LBA to CHS,

store (cylinder & 0x3FF, head & 0xFF, sector & 0x3F)

 

It's what Partition Magic does (prior to version 8.0?).

second way

convert LBA to CHS

if cylinder <= 1023,

store (cylinder & 0x3FF, head & 0xFF, sector & 0x3F)

else

store (1023, max_head & 0xFF, max_sector & 0x3F)

 

This is what Linux fdisk and TestDisk do.

 

 

 

When TestDisk checks the partition table, it considers both ways may be correct. But the second way is better because start CHS is always lower or equal to end CHS.

 

 

Example: A hard disk's logical geometry is 255 heads per cylinder and 63 sectors per head. A partition begins at LBA=46781280 or CHS=2912,0,1. This partition ends at 3072,254,63.

First way:

start: 864, 0, 1

end: 0,254,63

Second way:

start: 1023,254,63

end: 1023,254,63

 

 

NB: 1023 = 0x3FF (1023*255+254)*63+63-1=16450559 (2912*255+ 0)*63+ 1-1=46781280

 

Partition Magic (before version 8.0?) considered the second way as invalid; even though it's an agreed upon standard. TestDisk handles both without complaining.

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