ZRAMCTL(8) System Administration ZRAMCTL(8)NAMEzramctl - 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]
DESCRIPTIONzramctl 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.
OPTIONS-a, --algorithm lzo|lz4
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 list
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.
--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 size
Create a zram device of the specified size. Zram devices are
aligned to memory pages; when the requested size is not a multi‐
ple of the page size, it will be rounded up to the next multi‐
ple. When not otherwise specified, the unit of the size parame‐
ter 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 mean‐
ing as "KiB") or the suffixes KB (=1000), MB (=1000*1000), and
so on for GB, TB, PB, EB, ZB and YB.
-t, --streams number
Set the maximum number of compression streams that can be used
for the device. The default is one stream.
-V, --version
Display version information and exit.
-h, --help
Display help text and exit.
RETURN VALUEzramctl 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
SEE ALSO
Linux kernel documentation ⟨http://git.kernel.org/cgit/linux/kernel/git
/torvalds/linux.git/tree/Documentation/blockdev/zram.txt⟩.
AUTHORS
Timofey Titovets <nefelim4ag@gmail.com>
Karel Zak <kzak@redhat.com>
AVAILABILITY
The zramctl command is part of the util-linux package and is available
from https://www.kernel.org/pub/linux/utils/util-linux/.
util-linux July 2014 ZRAMCTL(8)
