Red Hat Enterprise Linux 3: System Administration Guide
Prev |  | Next

# Chapter 5. Managing Disk Storage

Many users need to view the existing partition table, change the size of the partitions, remove partitions, or add partitions from free space or additional hard drives. The utility `parted` allows users to perform these tasks. This chapter discusses how to use `parted` to perform file system tasks.

If you want to view the system's disk space usage or monitor the disk space usage, refer to Section 42.3 File Systems.

You must have the `parted` package installed to use the `parted` utility. To start `parted`, at a shell prompt as root, type the command `parted `/dev/hdb``, where `/dev/hdb` is the device name for the drive you want to configure. The `(parted)` prompt is displayed. Type `help` to view a list of available commands.

If you want to create, remove, or resize a partition, the device can not be in use (partitions can not be mounted, and swap space can not be enabled). The partition table should not be modified while in use because the kernel may not properly recognize the changes. Data could be overwritten by writing to the wrong partition because the partition table and partitions mounted do not match. The easiest way to achieve this it to boot your system in rescue mode. Refer to Chapter 11 Basic System Recovery for instructions on booting into rescue mode. When prompted to mount the file system, select Skip.

Alternately, if the drive does not contain any partitions in use, you can unmount them with the `umount` command and turn off all the swap space on the hard drive with the `swapoff` command.

Table 5-1 contains a list of commonly used `parted` commands. The sections that follow explain some of them in more detail.

Command | Description
--- | ---
`check `minor-num`` | Perform a simple check of the file system
`cp `from` `to`` | Copy file system from one partition to another; `from` and `to` are the minor numbers of the partitions
`help` | Display list of available commands
`mklabel `label`` | Create a disk label for the partition table
`mkfs `minor-num` `file-system-type`` | Create a file system of type `file-system-type`
`mkpart `part-type` `fs-type` `start-mb` `end-mb`` | Make a partition without creating a new file system
`mkpartfs `part-type` `fs-type` `start-mb` `end-mb`` | Make a partition and create the specified file system
`move `minor-num` `start-mb` `end-mb`` | Move the partition
`name `minor-num` `name`` | Name the partition for Mac and PC98 disklabels only
`print` | Display the partition table
`quit` | Quit `parted`
`rescue` `start-mb` `end-mb` | Rescue a lost partition from `start-mb` to `end-mb`
`resize `minor-num` `start-mb` `end-mb`` | Resize the partition from `start-mb` to `end-mb`
`rm `minor-num`` | Remove the partition
`select `device`` | Select a different device to configure
`set `minor-num` `flag` `state`` | Set the flag on a partition; `state` is either on or off

Table 5-1. `parted` commands

# 5.1. Viewing the Partition Table

After starting `parted`, type the following command to view the partition table:

    print

A table similar to the following appears:

    Disk geometry for /dev/hda: 0.000-9765.492 megabytes
    Disk label type: msdos
    Minor    Start       End     Type      Filesystem  Flags
    1          0.031    101.975  primary   ext3        boot
    2        101.975    611.850  primary   linux-swap
    3        611.851    760.891  primary   ext3
    4        760.891   9758.232  extended              lba
    5        760.922   9758.232  logical   ext3

The first line displays the size of the disk, the second line displays the disk label type, and the remaining output shows the partition table. In the partition table, the Minor number is the partition number. For example, the partition with minor number 1 corresponds to `/dev/hda1`. The Start and End values are in megabytes. The Type is one of primary, extended, or logical. The Filesystem is the file system type, which can be one of ext2, ext3, FAT, hfs, jfs, linux-swap, ntfs, reiserfs, hp-ufs, sun-ufs, or xfs. The Flags column lists the flags set for the partition. Available flags are boot, root, swap, hidden, raid, lvm, or lba.

| Tip
| To select a different device without having to restart `parted`, use the `select` command followed by the device name such as `/dev/hdb`. Then, you can view its partition table or configure it.

Prev | Home | Next
Additional Resources | Up | Creating a Partition