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1 | .TH ZRAMCTL 8 "July 2014" "util-linux" "System Administration" |
2 | .SH NAME | |
3 | zramctl \- set up and control zram devices | |
4 | .SH SYNOPSIS | |
5 | .ad l | |
6 | Get info: | |
7 | .sp | |
8 | .in +5 | |
9 | .BR zramctl " [options]" | |
10 | .sp | |
11 | .in -5 | |
12 | Reset zram: | |
13 | .sp | |
14 | .in +5 | |
15 | .B "zramctl \-r" | |
16 | .IR zramdev ... | |
17 | .sp | |
18 | .in -5 | |
19 | Print name of first unused zram device: | |
20 | .sp | |
21 | .in +5 | |
22 | .B "zramctl \-f" | |
23 | .sp | |
24 | .in -5 | |
f0b3e6c2 | 25 | Set up a zram device: |
0624d840 KZ |
26 | .sp |
27 | .in +5 | |
28 | .B zramctl | |
29 | .RB [ \-f " | "\fIzramdev\fP ] | |
30 | .RB [ \-s | |
31 | .IR size ] | |
f0b3e6c2 | 32 | .RB [ \-t |
0624d840 | 33 | .IR number ] |
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34 | .RB [ \-a |
35 | .IR algorithm ] | |
36 | .sp | |
f0b3e6c2 | 37 | .in -5 |
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38 | .ad b |
39 | .SH DESCRIPTION | |
40 | .B zramctl | |
41 | is used to quickly set up zram device parameters, to reset zram devices, and to | |
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42 | query the status of used zram devices. |
43 | .PP | |
44 | If no option is given, all non-zero size zram devices are shown. | |
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45 | .PP |
46 | Note that \fIzramdev\fP node specified on command line has to already exist. The command | |
47 | .B zramctl | |
48 | creates a new /dev/zram<N> nodes only when \fB\-\-find\fR option specified. It's possible | |
49 | (and common) that after system boot /dev/zram<N> nodes are not created yet. | |
0624d840 | 50 | .SH OPTIONS |
f0b3e6c2 | 51 | .TP |
a3612b81 | 52 | .BR \-a , " \-\-algorithm lzo" | lz4 | lz4hc | deflate | 842 |
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53 | Set the compression algorithm to be used for compressing data in the zram device. |
54 | .TP | |
55 | .BR \-f , " \-\-find" | |
3b3f4374 | 56 | Find the first unused zram device. If a \fB\-\-size\fR argument is present, then |
0624d840 | 57 | initialize the device. |
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58 | .TP |
59 | .BR \-n , " \-\-noheadings" | |
0624d840 | 60 | Do not print a header line in status output. |
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61 | .TP |
62 | .BR \-o , " \-\-output " \fIlist | |
63 | Define the status output columns to be used. If no output arrangement is | |
64 | specified, then a default set is used. | |
0624d840 | 65 | Use \fB\-\-help\fP to get a list of all supported columns. |
f0b3e6c2 | 66 | .TP |
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67 | .B \-\-output\-all |
68 | Output all available columns. | |
69 | .TP | |
f0b3e6c2 | 70 | .B \-\-raw |
0624d840 | 71 | Use the raw format for status output. |
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72 | .TP |
73 | .BR \-r , " \-\-reset" | |
74 | Reset the options of the specified zram device(s). Zram device settings | |
75 | can be changed only after a reset. | |
76 | .TP | |
77 | .BR \-s , " \-\-size " \fIsize | |
882be626 BS |
78 | Create a zram device of the specified \fIsize\fR. |
79 | Zram devices are aligned to memory pages; when the requested \fIsize\fR is | |
80 | not a multiple of the page size, it will be rounded up to the next multiple. | |
81 | When not otherwise specified, the unit of the \fIsize\fR parameter is bytes. | |
ef567176 | 82 | .IP |
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83 | The \fIsize\fR argument may be followed by the multiplicative suffixes KiB (=1024), |
84 | MiB (=1024*1024), and so on for GiB, TiB, PiB, EiB, ZiB and YiB (the "iB" | |
85 | is optional, e.g., "K" has the same meaning as "KiB") or the suffixes | |
86 | KB (=1000), MB (=1000*1000), and so on for GB, TB, PB, EB, ZB and YB. | |
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87 | .TP |
88 | .BR \-t , " \-\-streams " \fInumber | |
89 | Set the maximum number of compression streams that can be used for the device. | |
90 | The default is one stream. | |
91 | .TP | |
92 | .BR \-V , " \-\-version" | |
0624d840 | 93 | Display version information and exit. |
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94 | .TP |
95 | .BR \-h , " \-\-help" | |
96 | Display help text and exit. | |
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97 | |
98 | .SH RETURN VALUE | |
99 | .B zramctl | |
100 | returns 0 on success, nonzero on failure. | |
101 | ||
102 | .SH FILES | |
103 | .TP | |
104 | .I /dev/zram[0..N] | |
105 | zram block devices | |
106 | ||
107 | .SH EXAMPLE | |
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108 | The following commands set up a zram device with a size of one gigabyte |
109 | and use it as swap device. | |
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110 | .nf |
111 | .IP | |
112 | # zramctl --find --size 1024M | |
113 | /dev/zram0 | |
114 | # mkswap /dev/zram0 | |
115 | # swapon /dev/zram0 | |
116 | ... | |
117 | # swapoff /dev/zram0 | |
118 | # zramctl --reset /dev/zram0 | |
119 | .fi | |
b464fd62 SK |
120 | .SH SEE ALSO |
121 | .UR http://git.\:kernel.\:org\:/cgit\:/linux\:/kernel\:/git\:/torvalds\:/linux.git\:/tree\:/Documentation\:/blockdev\:/zram.txt | |
122 | Linux kernel documentation | |
123 | .UE . | |
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124 | .SH AUTHORS |
125 | .nf | |
126 | Timofey Titovets <nefelim4ag@gmail.com> | |
127 | Karel Zak <kzak@redhat.com> | |
128 | .fi | |
129 | .SH AVAILABILITY | |
130 | The zramctl command is part of the util-linux package and is available from | |
d673b74e | 131 | https://www.kernel.org/pub/linux/utils/util-linux/. |