| .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 |
| Set up a zram device: |
| .sp |
| .in +5 |
| .B zramctl |
| .RB [ \-f " | "\fIzramdev\fP ] |
| .RB [ \-s |
| .IR size ] |
| .RB [ \-t |
| .IR number ] |
| .RB [ \-a |
| .IR algorithm ] |
| .sp |
| .in -5 |
| .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 |
| .TP |
| .BR \-a , " \-\-algorithm lzo" | lz4 |
| Set the compression algorithm to be used for compressing data in the zram device. |
| .TP |
| .BR \-f , " \-\-find" |
| Find the first unused zram device. If a \fB--size\fR argument is present, then |
| initialize the device. |
| .TP |
| .BR \-n , " \-\-noheadings" |
| Do not print a header line in status output. |
| .TP |
| .BR \-o , " \-\-output " \fIlist |
| Define the status output columns to be used. If no output arrangement is |
| specified, then a default set is used. |
| Use \fB\-\-help\fP to get a list of all supported columns. |
| .TP |
| .B \-\-raw |
| Use the raw format for status output. |
| .TP |
| .BR \-r , " \-\-reset" |
| Reset the options of the specified zram device(s). Zram device settings |
| can be changed only after a reset. |
| .TP |
| .BR \-s , " \-\-size " \fIsize |
| Create a zram device of the specified \fIsize\fR. |
| Zram devices are aligned to memory pages; when the requested \fIsize\fR 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 \fIsize\fR parameter is bytes. |
| .IP |
| 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. |
| .TP |
| .BR \-t , " \-\-streams " \fInumber |
| Set the maximum number of compression streams that can be used for the device. |
| The default is one stream. |
| .TP |
| .BR \-V , " \-\-version" |
| Display version information and exit. |
| .TP |
| .BR \-h , " \-\-help" |
| Display help text 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 set up a zram device with a size of one gigabyte |
| and use it 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/. |
