Alternate method of running swapon?
bernd at petrovitsch.priv.at
Wed Jan 8 13:26:53 EST 2020
On 08/01/2020 19:09, Jeffrey Walton wrote:
> I work with an open source project. We have a VM but it is low-end.
> The machine suffers OOM kills. We don't have access to /etc/fstab.
Apparently you run too many (or too fat) programs;-)
> Everything is an upsell with the VPS provider.
> I'm trying to setup a swapfile during startup using Systemd but:
> # swapon /swapfile
> swapon: /swapfile: swapon failed: Operation not permitted
> This may be useful:
[... nope ....]
> My question is, is there a way to sidestep the restriction? Is it
> possible to ask the kernel to use the swapfile without using the
The swapon (and swapoff) command basically calls the swapon()
syscall (and swapoff() syscall, respectively) and their manual
page say the caller needs CAP_SYS_ADMIN capability which usually
means being "root".
Does it work in a root-shell?
The man page says further under errors:
---- snip ----
EPERM: The caller does not have the CAP_SYS_ADMIN capability.
Alternatively, the maximum number of swap files are already in
use; see NOTES below.
---- snip ----
The notes below just talk about the maximum numbers of swapfile
depending on the kernel version and activates features.
If the kernel is built/provided by the VPS provider, there may
be further limitations ....
PS: I'm not guessing why ....
"I dislike type abstraction if it has no real reason. And saving
on typing is not a good reason - if your typing speed is the main
issue when you're coding, you're doing something seriously wrong."
- Linus Torvalds
-------------- next part --------------
A non-text attachment was scrubbed...
Size: 2472 bytes
Desc: not available
More information about the Kernelnewbies