rescue

Tools and notes on using Grml as a rescue system, i.e. to rescue another Linux system.

data/partition handling

unsorted tools

• dd: convert and copy a file
• ddrescue: copies data from one file or block device to another
• partimage: Linux/UNIX utility to save partitions in a compressed image file
• cfdisk: Partition a hard drive
• nparted: Newt and GNU Parted based disk partition table manipulator
• parted-bf: The GNU Parted disk partition resizing program, small version
• testdisk: Partition scanner and disk recovery tool
• gpart: Guess PC disk partition table, find lost partitions
• autopsy:(frontend to the sleuth kit) finds deleted and existing data on allocated and unallocated space on virtually every filesystem.

ext2/ext3/ext4

• e2fsprogs: ext2 file system utilities and libraries
• e2tools: utilities for manipulating files in an ext2/ext3 filesystem
• e2undel: Undelete utility for the ext2 file system
• ext2resize: an ext2 filesystem resizer
• recover: Undelete files on ext2 partitions

XFS

• xfsdump: Administrative utilities for the XFS filesystem
• xfsprogs: Utilities for managing the XFS filesystem

JFS

• jfsutils: utilities for managing the JFS filesystem

NTFS

• ntfs-3g: tools for doing neat things in NTFS partitions from Linux
• scrounge-ntfs: data recovery program for NTFS file systems
• ntfsresize: resize ntfs partitions
• chntpw: list users (-l), reset password of a given user (-u), etc

Example Boot GRML Rescue System on HP Proliant Servers

Required:

• Access to the server via ILO (ssh)
• Access to a webserver (optional; for remote grml image)

Configure ILO VSP to COM1

• Ssh to ilo
• Power on server or reset server

       <code>
       </>hpiLO-> power on
       # or
       </>hpiLO-> power reset
       </code>
    * Start VSP
       <code>
       </>hpiLO-> vsp
       </code>
    * Press [ESC] [9] to start RBSU (Bios)
       <code>
       rbsu> SET CONFIG Embedded Serial Port COM 2; IRQ3; IO: 2F8h-2FFh
       rbsu> SET CONFIG Virtual Serial Port COM 1; IRQ4; IO: 3F8h-3FFh
       rbsu> SET CONFIG BIOS Serial Console Port COM 1; IRQ4; IO: 3F8h-3FFh
       rbsu> SET IPL CD 1
       rbsu> EXIT
       </code>

Insert remote GRML CD image on webserver

• Apache grml image webserver

    mkdir /tmp/iloimg
    cat > iloimg-httpd.conf <<HERE
    ServerRoot "/tmp/iloimg"
    DocumentRoot "/tmp/iloimg"
    User nobody
    Group nobody
    PidFile /tmp/iloimg/httpd.pid
    ErrorLog error.log
    Listen *:5555
    HERE
    # copy grml iso image to /tmp/iloimg
    /usr/sbin/httpd -f /tmp/iloimg/iloimg-httpd.conf -k start

• ILO Settings

      <code>
      </>hpiLO-> vm cdrom get
      </>hpiLO-> vm cdrom insert http://xxx.xxx.xxx.xxx:5555/grml_2009.05.iso
      </>hpiLO-> vm cdrom set boot_always
      </>hpiLO-> power warm
      </code>

• Or if the server has an cdrom drive, simply insert grml cd

Start Grml with serial console

GRML 2009.05

Just type "serial" at grml boot loader prompt

GRML 2009.10

Press [ESC] to show up grml boot loader prompt on vsp and than "serial"

GRML 2017.05 on a host with a "real" serial port

• open grml.iso with a hex editor such as dhex on linux
• search for the string "vesamenu bootsplash" to find the isolinux.cfg inside the image
• remove the # in front of "serial 0 9600"
• replace "vesamenu.cfg" with "console.cfg"
• If you can't see a prompt on the serial console after booting, you might have attached too late. Hit [TAB] to redisplay the prompt.