# phpman > man > zramctl(8)

[ZRAMCTL(8)](https://www.chedong.com/phpMan.php/man/ZRAMCTL/8/markdown)                              System Administration                             [ZRAMCTL(8)](https://www.chedong.com/phpMan.php/man/ZRAMCTL/8/markdown)



## NAME
       zramctl - set up and control zram devices

## SYNOPSIS
       Get info:
           **zramctl** [options]

       Reset zram:
           **zramctl** **-r** _zramdev_...

       Print name of first unused zram device:
           **zramctl** **-f**

       Set up a zram device:
           **zramctl** [**-f** | _zramdev_] [**-s** _size_] [**-t** _number_] [**-a** _algorithm_]

## DESCRIPTION
       **zramctl** is used to quickly set up zram device parameters, to reset zram devices, and to query
       the status of used zram devices.

       If no option is given, all non-zero size zram devices are shown.

       Note that _zramdev_ node specified on command line has to already exist. The command **zramctl**
       creates a new _/dev/zram<N>_ nodes only when **--find** option specified. It’s possible (and
       common) that after system boot _/dev/zram<N>_ nodes are not created yet.

## OPTIONS
### -a --algorithm
           Set the compression algorithm to be used for compressing data in the zram device.

### -f --find
           Find the first unused zram device. If a **--size** argument is present, then initialize the
           device.

### -n --noheadings
           Do not print a header line in status output.

### -o --output
           Define the status output columns to be used. If no output arrangement is specified, then
           a default set is used. Use **--help** to get a list of all supported columns.

### --output-all
           Output all available columns.

### --raw
           Use the raw format for status output.

### -r --reset
           Reset the options of the specified zram device(s). Zram device settings can be changed
           only after a reset.

### -s --size
           Create a zram device of the specified _size_. Zram devices are aligned to memory pages;
           when the requested _size_ is not a multiple of the page size, it will be rounded up to the
           next multiple. When not otherwise specified, the unit of the _size_ parameter is bytes.

           The _size_ argument may be followed by the multiplicative suffixes KiB (=1024), MiB
           (=1024*1024), and so on for GiB, TiB, PiB, EiB, ZiB and YiB (the "iB" is optional, e.g.,
           "K" has the same meaning as "KiB") or the suffixes KB (=1000), MB (=1000*1000), and so on
           for GB, TB, PB, EB, ZB and YB.

### -t --streams
           Set the maximum number of compression streams that can be used for the device. The
           default is use all CPUs and one stream for kernels older than 4.6.

### -V --version
           Display version information and exit.

### -h --help
           Display help text and exit.

## EXIT STATUS
       **zramctl** returns 0 on success, nonzero on failure.

## FILES
       _/dev/zram[0..N]_
           zram block devices

## EXAMPLE
       The following commands set up a zram device with a size of one gigabyte and use it as swap
       device.

            # zramctl --find --size 1024M
            /dev/zram0
            # mkswap /dev/zram0
            # swapon /dev/zram0
            ...
            # swapoff /dev/zram0
            # zramctl --reset /dev/zram0

## AUTHORS
       Timofey Titovets <<nefelim4ag@gmail.com>>, Karel Zak <<kzak@redhat.com>>

## SEE ALSO
       Linux kernel documentation
       <<http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/admin-guide/blockdev/zram.rst>>

## REPORTING BUGS
       For bug reports, use the issue tracker at <https://github.com/karelzak/util-linux/issues>.

## AVAILABILITY
       The **zramctl** command is part of the util-linux package which can be downloaded from Linux
       Kernel Archive <<https://www.kernel.org/pub/linux/utils/util-linux/>>.



util-linux 2.37.2                            2021-06-02                                   [ZRAMCTL(8)](https://www.chedong.com/phpMan.php/man/ZRAMCTL/8/markdown)