diff options
| -rw-r--r-- | doc/guix.texi | 34 | ||||
| -rw-r--r-- | gnu/services/base.scm | 54 |
2 files changed, 71 insertions, 17 deletions
diff --git a/doc/guix.texi b/doc/guix.texi index eddf77c7ab..2319bba2ba 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -13075,14 +13075,38 @@ A list of mapped devices. @xref{Mapped Devices}. @item @code{file-systems} A list of file systems. @xref{File Systems}. -@item @code{swap-devices} (default: @code{'()}) @cindex swap devices -A list of strings identifying devices or files to be used for ``swap +@cindex swap space +@item @code{swap-devices} (default: @code{'()}) +A list of UUIDs, file system labels, or 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")}. +Manual}). Here are some examples: + +@table @code +@item (list (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")) +Use the swap partition with the given UUID. You can learn the UUID of a +Linux swap partition by running @command{swaplabel @var{device}}, where +@var{device} is the @file{/dev} file name of that partition. + +@item (list (file-system-label "swap")) +Use the partition with label @code{swap}. Again, the +@command{swaplabel} command allows you to view and change the label of a +Linux swap partition. + +@item (list "/swapfile") +Use the file @file{/swapfile} as swap space. + +@item (list "/dev/sda3" "/dev/sdb2") +Use the @file{/dev/sda3} and @file{/dev/sdb2} partitions as swap space. +We recommend referring to swap devices by UUIDs or labels as shown above +instead. +@end table + 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}. +device (under @file{/dev/mapper}), 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: @code{%base-groups}) diff --git a/gnu/services/base.scm b/gnu/services/base.scm index 37b0a13ea7..07d9089b0a 100644 --- a/gnu/services/base.scm +++ b/gnu/services/base.scm @@ -2104,22 +2104,52 @@ instance." 'swap (lambda (device) (define requirement - (if (string-prefix? "/dev/mapper/" device) + (if (and (string? device) + (string-prefix? "/dev/mapper/" device)) (list (symbol-append 'device-mapping- (string->symbol (basename device)))) '())) - (shepherd-service - (provision (list (symbol-append 'swap- (string->symbol device)))) - (requirement `(udev ,@requirement)) - (documentation "Enable the given swap device.") - (start #~(lambda () - (restart-on-EINTR (swapon #$device)) - #t)) - (stop #~(lambda _ - (restart-on-EINTR (swapoff #$device)) - #f)) - (respawn? #f))))) + (define (device-lookup device) + ;; The generic 'find-partition' procedures could return a partition + ;; that's not swap space, but that's unlikely. + (cond ((uuid? device) + #~(find-partition-by-uuid #$(uuid-bytevector device))) + ((file-system-label? device) + #~(find-partition-by-label + #$(file-system-label->string device))) + (else + device))) + + (define service-name + (symbol-append 'swap- + (string->symbol + (cond ((uuid? device) + (string-take (uuid->string device) 6)) + ((file-system-label? device) + (file-system-label->string device)) + (else + device))))) + + (with-imported-modules (source-module-closure '((gnu build file-systems))) + (shepherd-service + (provision (list service-name)) + (requirement `(udev ,@requirement)) + (documentation "Enable the given swap device.") + (modules `((gnu build file-systems) + ,@%default-modules)) + (start #~(lambda () + (let ((device #$(device-lookup device))) + (and device + (begin + (restart-on-EINTR (swapon device)) + #t))))) + (stop #~(lambda _ + (let ((device #$(device-lookup device))) + (when device + (restart-on-EINTR (swapoff device))) + #f))) + (respawn? #f)))))) (define (swap-service device) "Return a service that uses @var{device} as a swap device." |