9

I have 16GB of RAM and the core system is run on 128GB sddisk. So I don't have space to use 16/32 GB for swap.

Can I create swap on another hard disk? Or it has to be on the same disk as the system?

EDIT

What are the steps to migrate swap from /dev/sdc3 to /dev/sdb. The file fstab looks like this

# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
# / was on /dev/sda2 during installation
UUID=6d9c9f84-02f0-4f59-b57f-6a4ebd06b87f /               ext4    errors=remount-ro 0       1
# /boot/efi was on /dev/sda1 during installation
UUID=4B73-5222  /boot/efi       vfat    defaults        0       1
# /home was on /dev/sda4 during installation
UUID=b0233bff-100f-4741-ad00-29ffc6f26057 /home           ext4    defaults        0       2
# swap was on /dev/sda3 during installation
UUID=1a3ad087-9ba3-4312-9307-a84dade9e1bf none            swap    sw              0       0
ubuntico
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  • hmmm... I've yet to see a linux installation where the 'core system' would take over 30 GB space :) – mike3996 Dec 16 '14 at 18:31
  • You are right about core system, but I meant to /home as well which is on the sddisk and already consumed 30GB of space (out of 70GB). – ubuntico Dec 16 '14 at 18:35
  • Take a look at How to increase swap space? as it could be best solution for almost any situation nowdays. Of course you could also create multiple swap partitions and/or files (using different physical storage media) to make it faster. – Sampo Sarrala Dec 16 '14 at 22:06

2 Answers2

7

Yes.

You can choose to do this at the time of installation, or you can make a swap partition with a tool such as gparted and then activate the swap with swapon. Add it to your fstab to make it available on boot.

For help with making the swap partition: How do I restore a swap partition I accidentally deleted?

For help with turning swap on: You literally just type sudo swapon into a terminal

For help with adding to your fstab: How do I add a swap partition after system installation?

Community
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Mitch
  • 4,697
5

Since you have 16GB of RAM, there is no need for a 'swap' partition. Also, the 'swap should be 1-2 times the RAM' rule is only valid for systems having less RAM, ie < 2GB.

You can create a swap partition on a separate drive by using mkswap and swapon.

Eg - To to migrate swap from /dev/sdc3 to /dev/sdb1 -

swapoff /dev/sdc3

mkswap /dev/sdb1

swapon /dev/sdb1

and edit swap entry in /etc/fstab.

Rohith Madhavan
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  • I am trying to enable hibernate and the system is not waking so I read that I have to make swap as large as RAM to make hibernate work. Now, how do you set the size of swap? Do I have to make swapon on each startup? – ubuntico Dec 16 '14 at 17:53
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    Create a new partition in the drive ie /dev/sdb1. Now, use the commands mkswap and swapon to create a swap partition and edit the fstab entry so that the system knows where the swap is located. This is a one-time process. – Rohith Madhavan Dec 16 '14 at 18:00
  • You can set the size at creation time. – Cees Timmerman Dec 23 '18 at 15:10