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#56 Ability to zero a linux swap partition
I would like to request the ability to zero a linux swap partition (although keeping it's swap partition signiture so the actual system using it will not be affected) in order to minimize images created off an entire disk containing such a partition.
Thank you.
On 4 Apr 2015 at 9:08, Andrei B. wrote:
To: "Ticket 56" 56@feature-requests.g4l.p.re.sf.net
From: "Andrei B." andrixnet@users.sf.net
Send reply to: "Ticket 56" 56@feature-requests.g4l.p.re.sf.net
Subject: [g4l:feature-requests] #56 Ability to zero a linux swap partition
Date sent: Sat, 04 Apr 2015 09:08:13 +0000
The zero function was designed to clear partitions that linux can mount and
then write zeros to directly. The swap partition isn't of that type. I just did a
test with this little scripted called clearswap and it does seem to do the job in
my test, but will have to see how to implement it.
The first line gets the partition that is listed as type swap. (assumes on 1?)
The second line gets the current UUID of the partition to be used in
recreating (mkswap)
The third line just prints the info will testing to make sure it was correct.
The forth line clears the physical partition
The fifth line then recreates the partition as a swap using the UUID
PART=
blkid | grep swap | cut -f 1 -d:UUID=
blkid | grep swap | cut -f 2 -d\"echo $PART $UUID
dd if=/dev/zero bs=20M of=$PART
mkswap $PART -U $UUID
So, it doesn't seem to be a big thing, but not sure what would happen with
swap partitions that are setup using label or perhaps.
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Related
Feature Requests: #56
I've just played a bit with that script as well.
Looks good. But needs to be adjusted for the case of multiple swap partitions.
I'll try and have a look at mkswap source as well. I admit I am unfamiliar with the on-disk format of the linux swap file.