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Diffstat (limited to 'disk-utils/mkswap.8')
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diff --git a/disk-utils/mkswap.8 b/disk-utils/mkswap.8 new file mode 100644 index 0000000..4f62046 --- /dev/null +++ b/disk-utils/mkswap.8 @@ -0,0 +1,173 @@ +'\" t +.\" Title: mkswap +.\" Author: [see the "AUTHOR(S)" section] +.\" Generator: Asciidoctor 2.0.15 +.\" Date: 2022-05-11 +.\" Manual: System Administration +.\" Source: util-linux 2.38.1 +.\" Language: English +.\" +.TH "MKSWAP" "8" "2022-05-11" "util\-linux 2.38.1" "System Administration" +.ie \n(.g .ds Aq \(aq +.el .ds Aq ' +.ss \n[.ss] 0 +.nh +.ad l +.de URL +\fI\\$2\fP <\\$1>\\$3 +.. +.als MTO URL +.if \n[.g] \{\ +. mso www.tmac +. am URL +. ad l +. . +. am MTO +. ad l +. . +. LINKSTYLE blue R < > +.\} +.SH "NAME" +mkswap \- set up a Linux swap area +.SH "SYNOPSIS" +.sp +\fBmkswap\fP [options] \fIdevice\fP [\fIsize\fP] +.SH "DESCRIPTION" +.sp +\fBmkswap\fP sets up a Linux swap area on a device or in a file. +.sp +The \fIdevice\fP argument will usually be a disk partition (something like \fI/dev/sdb7\fP) but can also be a file. The Linux kernel does not look at partition IDs, but many installation scripts will assume that partitions of hex type 82 (LINUX_SWAP) are meant to be swap partitions. (\fBWarning: Solaris also uses this type. Be careful not to kill your Solaris partitions.\fP) +.sp +The \fIsize\fP parameter is superfluous but retained for backwards compatibility. (It specifies the desired size of the swap area in 1024\-byte blocks. \fBmkswap\fP will use the entire partition or file if it is omitted. Specifying it is unwise \- a typo may destroy your disk.) +.sp +After creating the swap area, you need the \fBswapon\fP(8) command to start using it. Usually swap areas are listed in \fI/etc/fstab\fP so that they can be taken into use at boot time by a \fBswapon \-a\fP command in some boot script. +.SH "WARNING" +.sp +The swap header does not touch the first block. A boot loader or disk label can be there, but it is not a recommended setup. The recommended setup is to use a separate partition for a Linux swap area. +.sp +\fBmkswap\fP, like many others mkfs\-like utils, \fBerases the first partition block to make any previous filesystem invisible.\fP +.sp +However, \fBmkswap\fP refuses to erase the first block on a device with a disk label (SUN, BSD, ...). +.SH "OPTIONS" +.sp +\fB\-c\fP, \fB\-\-check\fP +.RS 4 +Check the device (if it is a block device) for bad blocks before creating the swap area. If any bad blocks are found, the count is printed. +.RE +.sp +\fB\-f\fP, \fB\-\-force\fP +.RS 4 +Go ahead even if the command is stupid. This allows the creation of a swap area larger than the file or partition it resides on. +.sp +Also, without this option, \fBmkswap\fP will refuse to erase the first block on a device with a partition table. +.RE +.sp +\fB\-q\fP, \fB\-\-quiet\fP +.RS 4 +Suppress output and warning messages. +.RE +.sp +\fB\-L\fP, \fB\-\-label\fP \fIlabel\fP +.RS 4 +Specify a \fIlabel\fP for the device, to allow \fBswapon\fP(8) by label. +.RE +.sp +\fB\-\-lock\fP[=\fImode\fP] +.RS 4 +Use exclusive BSD lock for device or file it operates. The optional argument \fImode\fP can be \fByes\fP, \fBno\fP (or 1 and 0) or \fBnonblock\fP. If the \fImode\fP argument is omitted, it defaults to \fByes\fP. This option overwrites environment variable \fB$LOCK_BLOCK_DEVICE\fP. The default is not to use any lock at all, but it\(cqs recommended to avoid collisions with \fBsystemd\-udevd\fP(8) or other tools. +.RE +.sp +\fB\-p\fP, \fB\-\-pagesize\fP \fIsize\fP +.RS 4 +Specify the page \fIsize\fP (in bytes) to use. This option is usually unnecessary; \fBmkswap\fP reads the size from the kernel. +.RE +.sp +\fB\-U\fP, \fB\-\-uuid\fP \fIUUID\fP +.RS 4 +Specify the \fIUUID\fP to use. The default is to generate a UUID. The format of the UUID is a series of +hex digits separated by hyphens, like this: "c1b9d5a2\-f162\-11cf\-9ece\-0020afc76f16". The UUID parameter +may also be one of the following: +.sp +\fBclear\fP +.RS 4 +clear the filesystem UUID +.RE +.sp +\fBrandom\fP +.RS 4 +generate a new randomly\-generated UUID +.RE +.sp +\fBtime\fP +.RS 4 +generate a new time\-based UUID +.RE +.RE +.sp +\fB\-v\fP, \fB\-\-swapversion 1\fP +.RS 4 +Specify the swap\-space version. (This option is currently pointless, as the old \fB\-v 0\fP option has become obsolete and now only \fB\-v 1\fP is supported. The kernel has not supported v0 swap\-space format since 2.5.22 (June 2002). The new version v1 is supported since 2.1.117 (August 1998).) +.RE +.sp +\fB\-\-verbose\fP +.RS 4 +Verbose execution. With this option \fBmkswap\fP will output more details about detected problems during swap area set up. +.RE +.sp +\fB\-h\fP, \fB\-\-help\fP +.RS 4 +Display help text and exit. +.RE +.sp +\fB\-V\fP, \fB\-\-version\fP +.RS 4 +Print version and exit. +.RE +.SH "ENVIRONMENT" +.sp +LIBBLKID_DEBUG=all +.RS 4 +enables libblkid debug output. +.RE +.sp +LOCK_BLOCK_DEVICE=<mode> +.RS 4 +use exclusive BSD lock. The mode is "1" or "0". See \fB\-\-lock\fP for more details. +.RE +.SH "NOTES" +.sp +The maximum useful size of a swap area depends on the architecture and the kernel version. +.sp +The maximum number of the pages that is possible to address by swap area header is 4294967295 (32\-bit unsigned int). The remaining space on the swap device is ignored. +.sp +Presently, Linux allows 32 swap areas. The areas in use can be seen in the file \fI/proc/swaps\fP. +.sp +\fBmkswap\fP refuses areas smaller than 10 pages. +.sp +If you don\(cqt know the page size that your machine uses, you can look it up with \fBgetconf PAGESIZE\fP. +.sp +To set up a swap file, it is necessary to create that file before initializing it with \fBmkswap\fP, e.g. using a command like +.sp +.if n .RS 4 +.nf +.fam C +# dd if=/dev/zero of=swapfile bs=1MiB count=$((8*1024)) +.fam +.fi +.if n .RE +.sp +to create 8GiB swapfile. +.sp +Please read notes from \fBswapon\fP(8) about \fBthe swap file use restrictions\fP (holes, preallocation and copy\-on\-write issues). +.SH "SEE ALSO" +.sp +\fBfdisk\fP(8), +\fBswapon\fP(8) +.SH "REPORTING BUGS" +.sp +For bug reports, use the issue tracker at \c +.URL "https://github.com/util\-linux/util\-linux/issues" "" "." +.SH "AVAILABILITY" +.sp +The \fBmkswap\fP command is part of the util\-linux package which can be downloaded from \c +.URL "https://www.kernel.org/pub/linux/utils/util\-linux/" "Linux Kernel Archive" "."
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