		Next

Partition Tools

Table of Contents

Alter boot volume

Goal change boot device from /dev/hda3 to /dev/hda2

cmd:sfdisk

Usage

To set /dev/hd?2 as boot devive:

sfdisk -A2 /dev/$HD

Comments

Using sfdisk to change boot devive is recommended, it does not require two steps to achieve so:

HD=hda

% sfdisk -l /dev/$HD

Disk /dev/hda: 7476 cylinders, 255 heads, 63 sectors/track
Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0

   Device Boot Start     End   #cyls    #blocks   Id  System
/dev/hda1          0+     63      64-    514048+  82  Linux swap
/dev/hda2         64     320     257    2064352+   b  Win95 FAT32
/dev/hda3   *    321     705     385    3092512+  83  Linux
/dev/hda4        706    7475    6770   54380025    f  Win95 Ext'd (LBA)
/dev/hda5        706+   1989    1284-  10313698+  83  Linux
[...]

% sfdisk -A2 /dev/$HD
Done

% sfdisk -l /dev/$HD

Disk /dev/hda: 7476 cylinders, 255 heads, 63 sectors/track
Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0

   Device Boot Start     End   #cyls    #blocks   Id  System
/dev/hda1          0+     63      64-    514048+  82  Linux swap
/dev/hda2   *     64     320     257    2064352+   b  Win95 FAT32
/dev/hda3        321     705     385    3092512+  83  Linux
/dev/hda4        706    7475    6770   54380025    f  Win95 Ext'd (LBA)
/dev/hda5        706+   1989    1284-  10313698+  83  Linux
[...]

Verified again at 2004.08.23.

save/restore disk partition setting and fix errors using sfdisk

HD=hda
HD=hdb
HD=sda

To check partition setting or errors, use the following command:

# check partition
sfdisk -V /dev/$HD

To backup the current disk partition setting, use the following command:

sfdisk -d /dev/$HD | tee partition.$HD.info

Most importantly, partitions can be recreated by this simple command:

# recreate partition
sfdisk --no-reread /dev/$HD < partition.$HD.info

Then reboot ASAP.

cmd:parted

debfoster parted libparted1.6-0 libreiserfs0.3-0
debfoster parted- libparted1.6-0- libreiserfs0.3-0-

(parted) select /dev/hda

(parted) print
Disk geometry for /dev/hda: 0.000-58644.140 megabytes
Disk label type: msdos
Minor    Start       End     Type      Filesystem  Flags
1          0.031    502.031  primary   linux-swap
2        502.031   2518.000  primary   FAT
3       2518.000   5538.032  primary   ext2        boot
4       5538.032  58643.525  extended              lba
5       5538.063  15610.034  logical
[...]

(parted) set 2 boot on
(parted) print
Disk geometry for /dev/hda: 0.000-58644.140 megabytes
Disk label type: msdos
Minor    Start       End     Type      Filesystem  Flags
1          0.031    502.031  primary   linux-swap
2        502.031   2518.000  primary   FAT         boot
3       2518.000   5538.032  primary   ext2
4       5538.032  58643.525  extended              lba
5       5538.063  15610.034  logical
[...]
(parted) quit

help

set MINOR FLAG STATE          change a flag on partition MINOR

MINOR is the partition number used by Linux. On msdos disk labels, the primary partitions number from 1-4, and logical partitions are 5 onwards. FLAG is one of: boot, root, swap, hidden, raid, lvm, lba STATE is one of: on, off