otrott
June 27, 2025, 4:47pm
1
hi there good evening
just created a swap-file on command line - like so
[martin@x220 ~]$ swapon -s
Dateiname Typ Größe Benutzt Priorität
/dev/sda2 partition 8555336 1425928 -2
[martin@x220 ~]$ ^[[200~sudo fallocate -l 1G /swapfile~
bash: $'\E[200~sudo': Kommando nicht gefunden.
[martin@x220 ~]$ sudo fallocate -l 1G /swapfile
[sudo] Passwort für martin:
[martin@x220 ~]$ sudo fallocate -l 1G /swapfile
[martin@x220 ~]$ sudo dd if=/dev/zero of=/swapfile bs=1024 count=1048576
1048576+0 Datensätze ein
1048576+0 Datensätze aus
1073741824 Byte (1,1 GB, 1,0 GiB) kopiert, 15,6564 s, 68,6 MB/s
[martin@x220 ~]$ sudo chmod 600 /swapfile
[martin@x220 ~]$ sudo mkswap /swapfile
Auslagerungsbereich Version 1 wird angelegt, Größe = 1024 MiB (1073737728 Bytes)
keine Bezeichnung, UUID=8fe303c8-1291-403c-bf2f-1f561dd24edb
[martin@x220 ~]$ sudo swapon /swapfile
[martin@x220 ~]$ sudo swapon --show
NAME TYPE SIZE USED PRIO
/dev/sda2 partition 8,2G 2,5G -2
/swapfile file 1024M 0B -3
[martin@x220 ~]$
guess that this is permanent - and will be so if i switch off the notebook and afterwards swith it on agian.
Indeed. swap-files are persistent, they need to be mentioned in fstab, though, as far as I know.
I used [1] as a source of info about swap, and the different sorts there are.3.1 Swap file creation they seem to describe different commands than the commands you seem to have used.
mkswap -U clear --size 4G --file /swapfile
swapon /swapfile
And in /etc/fstab:
/swapfile none swap defaults 0 0
[1] https://wiki.archlinux.org/title/Swap
How much RAM do you have? I tried using a SWAP partition the last time I reinstalled on my other computers and I didn’t notice any difference. In fact, the SWAP partition hardly got used, so I deleted it. I have 16GB of RAM on all of my systems.
otrott
June 27, 2025, 5:33pm
4
good evening dear SemLraug - hello oldthinker
first of all : many thanks for the quick reply. great to hear from you . - i need a swapfile - since i am on a Thinkpad X220 with only 4 gigs
thanks for the hint here: dear SemLraug
[quote=“SemLraug, post:2, topic:73000”]
mkswap -U clear --size 4G --file /swapfile
swapon /swapfile
nd in /etc/fstab:
/swapfile none swap defaults 0 0
[1] https://wiki.archlinux.org/title/Swap
thank you so much.
at the evening i am trying to test the behavior of the notebook
greetings
OK, yeah you need a SWAP file. Can the RAM be upgraded or is 4GB its max?
The question if swap is at all necessary always pops up as soon as someone mentions ‘swap’.
When i read [1] i decided from that moment to always create swap.
The next questions always is, which kind of swap.
[1] https://chrisdown.name/2018/01/02/in-defence-of-swap.html Zram vs swap partition vs swapfile
otrott
June 29, 2025, 7:50am
7
hi there - it can be upgreaded - in thinkpad t420 its possible and also in t 520 - i own both of them and love it for its robustness.
otrott
June 29, 2025, 8:38am
8
@SemLraug & @oldthinker
so if i got you right: swap-files are persistent, they need to be mentioned in fstab,
the process of creation the swap-file does not include and editing of the fstap?
Do:
sudo nano /etc/fstab
To check.
(Perhaps you prefer a different editor to nano, then you can use that one of course.)
otrott
June 29, 2025, 4:38pm
10
SemLraug:
sudo nano /etc/fstab
good day - well hmm - perhaps ill have to edit like so:
https://askubuntu.com/questions/126018/adding-a-new-swap-file-how-to-edit-fstab-to-enable-swap-after-reboot
Insert the following line in /etc/fstab for swap from the next boot:
/var/cache/swap/myswap none swap sw 0 0
well what do you suggest
btw: should i take 2 gigs in the swap configuration!?
swh
June 29, 2025, 4:50pm
11
From endeavouros wiki. I recommend that you follow the arch instructions
https://discovery.endeavouros.com/storage-and-partitions/adding-swap-after-installation/2021/03/
Edit the fstab configuration to add an entry for the swap file:
/etc/fstab
/swapfile none swap defaults 0 0
Note: The swap file must be specified by its location on the file system, not by its UUID or LABEL.
