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Diffstat (limited to 'disk-utils/mkswap.8')
-rw-r--r-- | disk-utils/mkswap.8 | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/disk-utils/mkswap.8 b/disk-utils/mkswap.8 new file mode 100644 index 000000000..2c02fbbe0 --- /dev/null +++ b/disk-utils/mkswap.8 @@ -0,0 +1,86 @@ +.\" Copyright 1992, 1993 Rickard E. Faith (faith@cs.unc.edu) +.\" May be distributed under the GNU General Public License +.\" Modified with suggestions from Linus, Mon Feb 1 21:40:49 1993 +.\" Modified with patches from Kai, Wed Jun 22 21:54:56 1994 +.\" Patches from jaggy@purplet.demon.co.uk (Mike Jagdis), Wed Feb 8 1995 +.\" Added comments from Nick Holloway, Sat Feb 11 1995, faith@cs.unc.edu +.\" " +.TH MKSWAP 8 "8 February 1995" "Linux 1.0" "Linux Programmer's Manual" +.SH NAME +mkswap \- set up a Linux swap device +.SH SYNOPSIS +.B "mkswap [ \-c ]" +.IB device " [" size-in-blocks "]" +.SH DESCRIPTION +.B mkswap +sets up a Linux swap area on a device (usually a disk partition). + +The +.I device +is usually of the following form: + +.nf +.RS +/dev/hda[1-8] +/dev/hdb[1-8] +/dev/sda[1-8] +/dev/sdb[1-8] +.RE +.fi + +The +.I size-in-blocks +parameter is the desired size of the file system, in blocks. This +information is determined automatically by mkswap if it is omitted. Block +counts are rounded down to pages of 4 kB each. Only block counts equal to +or greater than 40 and equal to or less than 131072 are allowed. Block +counts greater than 130752 are (silently) rounded down to 130752. + +As Nick Holloway explains, the actual maximum for each swap file/partition +is: +.RS +(4096 - 10) * 8 * 4096 = 133890048 bytes = 130752 blocks = 127.6875 Mb +.RE +This is because a single page is used to hold the swap bitmap at the +start of the partition, where each bit is a single 4K page. The reason +for the -10, is that the signature is "SWAP-SPACE" -- 10 characters. + +.B mkswap +can also set up swap files, although the file has to be created first. A +sequence of commands similar to the following is reasonable for this +purpose: + +.nf +.RS +# dd if=/dev/zero of=swapfile bs=1024 count=8192 +# mkswap swapfile 8192 +# sync +# swapon swapfile +.RE +.fi + +Note that the regular file has to be created before running +.B mkswap +on the file, and that the file must not contain any holes (so, using +.BR cp (1) +to create the file is not acceptable). + +.SH OPTIONS +.TP +.B \-c +Check the device for bad blocks before creating the file system. If any +are found, the count is printed. This option is meant to be used for swap +partitions +.BR only , +and should +.B not +be used for regular files! To make sure that regular files do not contain +bad blocks, the partition that contains the regular file should have been +created with +.BR "mkfs -c" . +.SH "SEE ALSO" +.BR fsck (8), +.BR mkfs (8), +.BR fdisk (8) +.SH AUTHOR +Linus Torvalds (torvalds@cs.helsinki.fi) |