fsadm Command in Linux
The fsadm command in Linux checks and resizes the filesystem on a device. The device can also be the dm-crypt encrypted device. The dm-crypt kernel-level encryption system allows users to encrypt files, partitions, and disks.
The fsadm command uses the same API for various filesystems such as ext2, ext3, ext4, ReiserFS, and XFS. Moreover, it is a simple and easy-to-use utility for checking and managing the filesystem on Linux.
Table of Contents
Here is a comprehensive guide to the options available with the fsadm command −
Syntax of fsadm Command
The syntax for checking the filesystem using the Linux fsadm command is as follows −
fsadm [options] check [device]
The syntax for resizing the filesystem using the fsadm command is given below −
fsadm [options] resize [device] [size]
The [options] field is used to specify the options to modify the command's behavior. While [device] is used to specify the device that needs to be checked and resized. The [size] field is used to specify the new size in [B|K|M|G|T|P|E] of the device that is to be resized.
Note − If the size is not specified the fsadm command will resize the filesystem using the entire available space of the underlying device.
Options of fsadm Command
The options used with the fsadm command are listed in the following table −
| Flags | Options | Description |
|---|---|---|
| -e | --ext-offline | It unmounts the filesystem before resizing |
| -f | --force | It bypasses the checks |
| -h | --help | It displays help |
| -l | --lvresize | It allows resizing of the logical volume |
| -n | --dry-run | To execute the command without making the changes |
| -r | --resizefs | It automatically resizes the filesystem when used with -l / --lvresize |
| -v | --verbose | It displays a detailed output |
| -y | --yes | It answers yes to any prompt |
| -c | --cryptresize | It resizes the logical volume that is encrypted using dm-crypt |
Examples of fsadm Command in Linux
This section demonstrates the usage of the Linux fsadm command in Linux with examples −
Checking Filesystem
To check the filesystem of a device, use the check argument −
sudo fsadm -v check /dev/vda2
The -v option is used for verbose output.
sudo fsadm -v check /dev/mapper/ubuntu--vg-ubuntu--lv
The /dev/mapper/ubuntu--vg-ubuntu--lv is the logical volume.
Resizing a Filesystem
To resize a filesystem using the fsadm command, use the resize option −
sudo fsadm -e resize /dev/vda2 1G
The -e option unmounts the filesystem before resizing.
Resizing a Filesystem with Verbose Output
To get a detailed output while resizing a filesystem, use the -v or --verbose option with the fsadm command −
sudo fsadm -v resize /dev/vda2 1G
Resizing a Logical (LVM) Device
To resize the logical volume, use the -l or --lvresize option −
sudo fsadm -l resize /dev/mapper/ubuntu--vg-ubuntu--lv 1G
Resizing an Encrypted Filesystem
If the volume is encrypted with the dm-crypt encryption system, then it can be resized using the -c or --cryptresize option −
sudo fsadm -c resize /dev/mapper/ubuntu--vg-ubuntu--lv 1G
Dry Running the Filesystem Resize
To dry run the filesystem resize, use the -n or --dry-run option −
sudo fsadm -l -n -v resize /dev/mapper/ubuntu--vg-ubuntu--lv 1G
This command will not make any changes to the filesystem, it will just demonstrate the process.
Conclusion
The fsadm command in Linux is used to identify and resize the filesystem. It is a handy filesystem management tool that can do both check and resize the filesystem. It can also be used to resize the logical device, and dm-crypt encrypted devices.