Can you make swap bigger this way?

Support and Help
1

Ubuntu Version

Ubuntu 24.04 LTS

Desktop Environment (if applicable)

GNOME

Problem Description

I was told you can get more swap space using these commands
mkswap -U clear --size 4G --file /path/to/swapfile
swapon /path/to/swapfile
Can you verify if this will work? Thanks.

2

No, that won’t work.

mkswap has no --size or --file options - it only formats an already existing file or block device.

On 24.04, swap is normally /swap.img.
To make a 4 GB swapfile, allocate the file first, set permissions, format, and enable it

sudo swapoff /swap.img
sudo fallocate -l 4G /swap.img
sudo chmod 600 /swap.img
sudo mkswap /swap.img
sudo swapon /swap.img

Check the active size with swapon --show.

1 Like
3

Can we please confirm you are using default ext4 and not something like btrfs or xfs

Thanks

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4

Please change your topic title to

  • How to add secondary swap space as a swapfile?

The sequence you are looking for is the following, IF you want a swapFILE and not a swap partition:

swapfile="/path_to_swapfile"
swaplabel="SWAPFILE"

sudo fallocate -l 4G ${swapfile}

sudo chmod 600 ${swapfile}

sudo mkswap -L ${swaplabel} ${swapfile}

sudo swapon ${swapfile}

To make it permanent:

echo "\n\n# Manually created swapfile\n${swapfile} none swap sw 0 0" >>/etc/fstab

P.S. Sorry, I just saw that @steelf had already given the similar sequence with a hardcoded path. :slight_smile:

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5

No worries, now let’s see who gets the likes :smile:

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