There is no reason why fallocate(1) should not be preferred instead of
'dd if=/dev/zero of=swapfile' with it's cumbersome size spec.
Signed-off-by: Sami Kerola <kerolasa@iki.fi>
Signed-off-by: Karel Zak <kzak@redhat.com>
Historically mkswap avoids wiping any signature on "whole disk",
until force option is given.
While the idea is that it should not wipe possible boot loader,
in reality it leads to many situations where e.g. LUKS device
is overwritten but still can be detected as LUKS (but unusable).
Patch chnges behaviour that only if partition table is detected,
signatures are not wiped.
Also it removes check for block device - loop device can now
map partitions in-kernel, so using mkswap on disk image in file
should behave the same as on disk.
Also it adds warning that know signature was wiped.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Use dates without the day, use the full month name, put "util-linux" in
the lower left corner, and "User Commands" or "System Administration"
at the top center.
Also improve here and there the one-line program description.
Signed-off-by: Benno Schulenberg <bensberg@justemail.net>
The update will also expand kernel version numbers to have a
month and year next to them. This should help users can get idea
how long, for example, swap v1 has been around.
[kzak@redhat.com: - modify synopsis, remove duplicate info about page size]
Signed-off-by: Sami Kerola <kerolasa@iki.fi>
Signed-off-by: Karel Zak <kzak@redhat.com>
Note that option -v0 is obsolete, and remove the now unneeded comment
about new-style swap areas. Further doublespace sentences, add some
commas and articles, and alphabetize the options.
Signed-off-by: Benno Schulenberg <bensberg@justemail.net>
The kernel has not supported v0 swap space format since 2.5.22. The
new version v1 is supported since 2.1.117.
Signed-off-by: Karel Zak <kzak@redhat.com>
A friend of mine is looking into the possibility of cloning Debian
(and other) systems automatically and stomped over swap partitions
getting assigned new UUIDs every time the new harddisk is partitioned
and swap is created.
It's essential when partitions are to be recognised by their uuid and
not by their old device path anymore.
Addresses-Ubuntu-Bug: #66637
Signed-off-by: LaMont Jones <lamont@debian.org>
Signed-off-by: Karel Zak <kzak@redhat.com>
mkswap(8) enforces to use v0 swap format when pagesize > 16kB.
(use case might be ppc64 with CONFIG_PPC_64K_PAGES).
As version 0 swap is not supported anymore by recent kernels, the
behaviour in this case is rather strange.
Here is a testcase:
for i in 4 8 16 32 64; do mkswap -p `expr $i \* 1024` ./swap.file; done
Setting up swapspace version 1, size = 4294963 kB
Using user-specified page size 8192, instead of the system values
4096/4096
Setting up swapspace version 1, size = 4294959 kB
Using user-specified page size 16384, instead of the system values
4096/4096
Setting up swapspace version 1, size = 4294950 kB
Using user-specified page size 32768, instead of the system values
4096/4096
Setting up swapspace version 0, size = 4294934 kB
Using user-specified page size 65536, instead of the system values
4096/4096
Setting up swapspace version 0, size = 4294901 kB
Signed-off-by: Matthias Koenig <mkoenig@suse.de>
Signed-off-by: Karel Zak <kzak@redhat.com>
Sami Kerola
Milan Broz
Davidlohr Bueso
Benno Schulenberg
Karel Zak
Peter Breitenlohner
Martin Schulze
Matthias Koenig