.TH ZRAMCTL 8 "July 2014" "util-linux" "System Administration"
.SH NAME
zramctl \- set up and control zram devices
.SH SYNOPSIS
.ad l
Get info:
.sp
.in +5
.BR zramctl " [options]"
.sp
.in -5
Reset zram:
.sp
.in +5
.B "zramctl \-r"
.IR zramdev ...
.sp
.in -5
Print name of first unused zram device:
.sp
.in +5
.B "zramctl \-f"
.sp
.in -5
Setup zram device:
.sp
.in +5
.B zramctl
.RB [ \-f " | "\fIzramdev\fP ]
.RB [ \-s
.IR size ]
.RB \ [ \-t
.IR number ]
.in +8
.RB [ \-a
.IR algorithm ]
.sp
.in -13
.ad b
.SH DESCRIPTION
.B 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 zram devices
are shown.
.SH OPTIONS
.IP "\fB\-a, \-\-algorithm \fI{lzo|lz4}\fP"
Set compression algorithm used for compress data in zram device.
.IP "\fB\-f, \-\-find\fP"
Find the first unused zram device. If a \fB--size\fR argument is present, then
initialize the device.
.IP "\fB\-h, \-\-help\fP"
print help
.IP "\fB\-h, \-\-noheadings\fP"
Do not print a header line in status output.
.IP "\fB\-o, \-\-output \fIlist\fP"
Define the status output columns to use. If no output arrangement is specified,
then a default set is used.
Use \fB\-\-help\fP to get a list of all supported columns.
.IP "\fB\-r, \-\-reset\fP
Reset options specified zram device(s). Zram device setting can be changed only
after reset.
.IP "\fB\-\-raw\fP"
Use the raw format for status output.
.IP "\fB\-s, \-\-size\fP \fIsize\fP
Force zram driver to reread size of the file associated with the specified zram device
The \fIsize\fR 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.
.IP "\fB\-t, \-\-streams \fInumber\fP"
Set number of maximum compress streams what used for device. The default is one stream.
.IP "\fB\-V, \-\-version\fP"
Display version information and exit.
.SH RETURN VALUE
.B zramctl
returns 0 on success, nonzero on failure.
.SH FILES
.TP
.I /dev/zram[0..N]
zram block devices
.SH EXAMPLE
The following commands can be used for setup the zram device with gigabyte size
and using as swap device.
.nf
.IP
# zramctl --find --size 1024M
/dev/zram0
# mkswap /dev/zram0
# swapon /dev/zram0
...
# swapoff /dev/zram0
# zramctl --reset /dev/zram0
.fi
.SH AUTHORS
.nf
Timofey Titovets <nefelim4ag@gmail.com>
Karel Zak <kzak@redhat.com>
.fi
.SH AVAILABILITY
The zramctl command is part of the util-linux package and is available from
ftp://ftp.kernel.org/pub/linux/utils/util-linux/.
