NAME
zramctl - set up and control zram devices
SYNOPSIS
Get info:
Reset zram:
Print name of first unused zram device:
Set up a zram device:
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 lzo|lz4|lz4hc|deflate|842|zstd
The list of supported algorithms could be inaccurate as it depends on the current kernel configuration. A basic overview can be obtained by using the command "cat /sys/block/zram0/comp_algorithm"; however, please note that this list might also be incomplete. This is due to the fact that ZRAM utilizes the Crypto API, and if certain algorithms were built as modules, it becomes impossible to enumerate all of them.
-f, --find
-n, --noheadings
-o, --outputlist
The default list of columns may be extended if list is specified in the format +list (e.g., zramctl -o+COMP-RATIO).
-p, --algorithm-params
--output-all
--raw
-r, --reset
-s, --sizesize
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, --streamsnumber
-h, --help
-V, --version
EXIT STATUS
zramctl returns 0 on success, nonzero on failure.
FILES
/dev/zram[0..N]
EXAMPLE
The following commands set up a zram device with a size of one gigabyte and use it as swap device.
\n
# zramctl --find --size 1024M
\n
/dev/zram0
\n
# mkswap /dev/zram0
\n
# swapon /dev/zram0
\n
...
\n
# swapoff /dev/zram0
\n
# zramctl --reset /dev/zram0AUTHORS
Timofey Titovets <[email protected]>, Karel Zak <[email protected]>
SEE ALSO
Linux kernel documentation <https://docs.kernel.org/admin-guide/blockdev/zram.html>
REPORTING BUGS
For bug reports, use the issue tracker <https://github.com/util-linux/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/>.