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| -rw-r--r-- | doc/guix.texi | 36 |
1 files changed, 33 insertions, 3 deletions
diff --git a/doc/guix.texi b/doc/guix.texi index 9a657c18f8..47456f3cd1 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -7063,6 +7063,26 @@ mkswap /dev/sda2 swapon /dev/sda2 @end example +Alternatively, you may use a swap file. For example, assuming that in +the new system you want to use the file @file{/swapfile} as a swap file, +you would run@footnote{This example will work for many types of file +systems (e.g., ext4). However, for copy-on-write file systems (e.g., +btrfs), the required steps may be different. For details, see the +manual pages for @command{mkswap} and @command{swapon}.}: + +@example +# This is 10 GiB of swap space. Adjust "count" to change the size. +dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240 +# For security, make the file readable and writable only by root. +chmod 600 /mnt/swapfile +mkswap /mnt/swapfile +swapon /mnt/swapfile +@end example + +Note that if you have encrypted the root partition and created a swap +file in its file system as described above, then the encryption also +protects the swap file, just like any other file in that file system. + @node Proceeding with the Installation @subsection Proceeding with the Installation @@ -7516,9 +7536,12 @@ A list of file systems. @xref{File Systems}. @item @code{swap-devices} (default: @code{'()}) @cindex swap devices -A list of strings identifying devices to be used for ``swap space'' -(@pxref{Memory Concepts,,, libc, The GNU C Library Reference Manual}). -For example, @code{'("/dev/sda3")}. +A list of strings identifying devices or files to be used for ``swap +space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference +Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}. +It is possible to specify a swap file in a file system on a mapped +device, provided that the necessary device mapping and file system are +also specified. @xref{Mapped Devices} and @ref{File Systems}. @item @code{users} (default: @code{%base-user-accounts}) @itemx @code{groups} (default: @var{%base-groups}) @@ -7861,6 +7884,13 @@ and use it as follows: (type luks-device-mapping)) @end example +@cindex swap encryption +It is also desirable to encrypt swap space, since swap space may contain +sensitive data. One way to accomplish that is to use a swap file in a +file system on a device mapped via LUKS encryption. In this way, the +swap file is encrypted because the entire device is encrypted. +@xref{Preparing for Installation,,Disk Partitioning}, for an example. + A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1} may be declared as follows: |