2 Resizing file systems #
Resizing file systems—not to be confused with resizing partitions or volumes—can be used to make space available on physical volumes or to use additional space available on a physical volume.
2.1 Use cases #
It is strongly recommended to use the YaST Partitioner to resize partitions or logical volumes. When doing so, the file system will automatically be adjusted to the new size of the partition or volume. However, there are some cases where you need to resize the file system manually, because they are not supported by YaST:
After having resized a virtual disk of a VM Guest.
After having resized a volume from a network-attached storage.
After having manually resized partitions (for example by using
fdisk
orparted
) or logical volumes (for example by usinglvresize
).When wanting to shrink Btrfs file systems (as of SUSE Linux Enterprise Server 12, YaST only supports growing Btrfs file systems).
2.2 Guidelines for resizing #
Resizing any file system involves some risks that can potentially result in losing data.
To avoid data loss, ensure that you back up your data before you begin any resizing task.
Consider the following guidelines when planning to resize a file system.
2.2.1 File systems that support resizing #
The file system must support resizing to take advantage of increases in available space for the volume. In SUSE Linux Enterprise Server, file system resizing utilities are available for file systems Ext2, Ext3, and Ext4. The utilities support increasing and decreasing the size as follows:
File System |
Utility |
Increase Size (Grow) |
Decrease Size (Shrink) |
---|---|---|---|
Btrfs |
|
Online |
Online |
XFS |
|
Online |
Not supported |
Ext2 |
|
Online or offline |
Offline only |
Ext3 |
|
Online or offline |
Offline only |
Ext4 |
|
Online or offline |
Offline only |
2.2.2 Increasing the size of a file system #
You can grow a file system to the maximum space available on the device, or specify an exact size. Ensure that you grow the size of the device or logical volume before you attempt to increase the size of the file system.
When specifying an exact size for the file system, ensure that the new size satisfies the following conditions:
The new size must be greater than the size of the existing data; otherwise, data loss occurs.
The new size must be equal to or less than the current device size because the file system size cannot extend beyond the space available.
2.2.3 Decreasing the size of a file system #
When decreasing the size of the file system on a device, ensure that the new size satisfies the following conditions:
The new size must be greater than the size of the existing data; otherwise, data loss occurs.
The new size must be equal to or less than the current device size because the file system size cannot extend beyond the space available.
If you plan to also decrease the size of the logical volume that holds the file system, ensure that you decrease the size of the file system before you attempt to decrease the size of the device or logical volume.
Decreasing the size of a file system formatted with XFS is not possible, since such a feature is not supported by XFS.
2.3 Changing the size of a Btrfs file system #
The size of a Btrfs file system can be changed by using the btrfs
filesystem resize
command when the file system is mounted.
Increasing and decreasing the size are both supported while the file system
is mounted.
Open a terminal.
Make sure the file system you want to change is mounted.
Change the size of the file system using the
btrfs filesystem resize
command with one of the following methods:To extend the file system size to the maximum available size of the device, enter
>
sudo
btrfs filesystem resize max /mntTo extend the file system to a specific size, enter
>
sudo
btrfs filesystem resize SIZE /mntReplace SIZE with the desired size in bytes. You can also specify units on the value, such as 50000K (kilobytes), 250M (megabytes), or 2G (gigabytes). Alternatively, you can specify an increase or decrease to the current size by prefixing the value with a plus (
+
) or a minus (-
) sign, respectively:>
sudo
btrfs filesystem resize +SIZE /mnt sudo btrfs filesystem resize -SIZE /mnt
Check the effect of the resize on the mounted file system by entering
>
df -hThe Disk Free (
df
) command shows the total size of the disk, the number of blocks used, and the number of blocks available on the file system. The -h option prints sizes in human-readable format, such as 1K, 234M, or 2G.
2.4 Changing the size of an XFS file system #
The size of an XFS file system can be increased by using the
xfs_growfs
command when the file system is mounted.
Reducing the size of an XFS file system is not possible.
Open a terminal.
Make sure the file system you want to change is mounted.
Increase the size of the file system using the
xfs_growfs
command. The following example expands the size of the file system to the maximum value available. Seeman 8 xfs_growfs
for more options.>
sudo
xfs_growfs -d /mntCheck the effect of the resize on the mounted file system by entering
>
df -hThe Disk Free (
df
) command shows the total size of the disk, the number of blocks used, and the number of blocks available on the file system. The -h option prints sizes in human-readable format, such as 1K, 234M, or 2G.
2.5 Changing the size of an ext2, ext3, or ext4 file system #
The size of Ext2, Ext3, and Ext4 file systems can be increased by using the
resize2fs
command, regardless of whether the respective
partition is mounted or not. To decrease the size of an Ext file system it
needs to be unmounted.
Open a terminal.
If the file system size should be decreased, unmount it.
Change the size of the file system using one of the following methods:
To extend the file system size to the maximum available size of the device called
/dev/sda1
, enter>
sudo
resize2fs /dev/sda1If a size parameter is not specified, the size defaults to the size of the partition.
To change the file system to a specific size, enter
>
sudo
resize2fs /dev/sda1 SIZEThe SIZE parameter specifies the requested new size of the file system. If no units are specified, the unit of the size parameter is the block size of the file system. Optionally, the size parameter can be suffixed by one of the following unit designations:
s
for 512 byte sectors;K
for kilobytes (1 kilobyte is 1024 bytes);M
for megabytes; orG
for gigabytes.
Wait until the resizing is completed before continuing.
If the file system is not mounted, mount it now.
Check the effect of the resize on the mounted file system by entering
>
df -hThe Disk Free (
df
) command shows the total size of the disk, the number of blocks used, and the number of blocks available on the file system. The -h option prints sizes in human-readable format, such as 1K, 234M, or 2G.