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2. Volumes

2.1 PC Partitions

GNU parted

GNU Parted is a program for creating, destroying, resizing, checking and copying partitions, and the filesystems on them.

This is useful for creating space for new operating systems, reorganising disk usage, copying data between hard disks, and "disk imaging" - replicating installations over many computers.

Parted has support for these operations: 

Filesystem      detect  create  resize  copy    check
ext2            *       *       *1      *2      *3
fat             *       *       *4      *4      *
linux-swap      *       *       *       *       *

NOTES:

(1) The start of the partition must stay fixed for ext2.

(2) The partition you copy to must be bigger (or exactly the same size) as the partition you copy from.

(3) Limited checking is done when the filesystem is opened. This is the only checking at the moment. All commands (including resize) will gracefully fail, leaving the filesystem in tact, if there are any errors in the file system (and the vast majority of errors in general).

(4) The size of the new partition, after resizing or copying, is restricted by the cluster size for fat (mainly affects FAT16). This is worse than you think, because you don't get to choose your cluster size (it's a bug in Windows, but you want compatibility, right?).

So, in practise, you can always shrink your partition (because Parted can shrink the cluster size), but you may not be able to grow the partition to the size you want. If you don't have any problems with using FAT32, you will always be able to grow the partition to the size you want.

Summary: you can always shrink your partition. If you can't use FAT32 for some reason, you may not be able to grow your partition.

Repairing corrupted partition table

Fixdisktable

This is a utility that handles ext2, FAT, NTFS, ufs, BSD disklabels (but not yet old Linux swap partitions); it actually will rewrite the partition table, if you give it permission.

gpart

GPART is a utility that handles ext2, FAT, Linux swap, HPFS, NTFS, FreeBSD and Solaris/x86 disklabels, minix, reiser fs; it prints a proposed contents for the primary partition table, and is well-documented.

rescuept

Recognizes ext2 superblocks, FAT partitions, swap partitions, and extended partition tables; it may also recognize BSD disklabels and Unixware 7 partitions. It prints out information that can be used with fdisk or sfdisk to reconstruct the partition table. It is in the non-installed part of the util-linux distribution.

findsuper

Small utility that finds blocks with the ext2 superblock signature, and prints out location and some info. It is in the non-installed part of the e2progs distribution.

2.2 Other partitions

Because I use only Intel x86 machines, any contributions (or non-x86 machine donation ;-) ) are very welcome. If you can provide any useful information, don't hesitate to mail me.

ADFS partitions

Amiga partitions

ATARI partitions

Macintosh partitions

OSF partitions

Sun partitions

Ultrix partitions

2.3 Unix disklabels

(todo)

BSD disklabel

(todo)

UnixWare disklabel

UnixWare VTOC (Volume Table Of Contents) divides disk partition to 16 logical partitions. Linux kernel supports UnixWare VTOC, you must check "UnixWare slices support (EXPERIMENTAL)" and recompile your kernel. Another way of reading UnixWare disklabel is using GPL port of prtvtoc(1) command, which is in vxtools package.

SCO OpenServer disklabel

(todo)

Sun Solaris disklabel

(todo)

2.4 Windows NT volumes

This linux-kernel driver allows you to access and mount linear and stripe set volumes.

Repairing "fault tolerant" NTFS disks using FTEdit

If you have a Windows NT Workstation or Server configured for fault tolerant (FT) partitions (such as stripes with parity and volume sets), and those partitions are inaccessible and appear in Disk Administrator as type Unknown, you can possibly make them accessible again by using the utility FTEDIT.

2.5 MD - Multiple Devices driver for Linux

This driver lets you combine several hard disk partitions into one logical block device. This can be used to simply append one partition to another one or to combine several redundant hard disks to a RAID1/4/5 device so as to provide protection against hard disk failures. This is called "Software RAID" since the combining of the partitions is done by the kernel.

2.6 LVM - Logical Volume Manager (HP-UX LVM?)

Linux implementation is available here:

2.7 VxVM - Veritas Volume Manager

For more information about Veritas Volume Manager see http://www.veritas.com/.

See also: VxFS (Veritas Journaling Filesystem).

2.8 IBM OS/2 LVM

Logical Volume Manager is available in OS/2 WarpServer 5. It allows you to create linear volumes on several disks/partitions. Some people say that it's compatible with IBM AIX Logical Volume Manager.

See also: HPFS, JFS

2.9 StackVM

StackVM is CrosStor's volume manager. Using StackVM the administrator can combine multiple physical disk slices into a single logical device know as a vdisk. Vdisk is short for virtual disk. The physical disks can be combined to form a concatenation, RAID 0 (stripe), RAID 1 (mirror), RAID 4 or RAID 5. In addition a single disk partition can be subdivided into multiple simple vdisks. For more information see CrosStor homepage at http://www.crosstor.com/.

2.10 Novell NetWare volumes

NetWare volumes are used for NWFS-386 filesystem.

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