Re: An idea for swap partition size vs. swap space size in use handling

Van: Mark Millard <marklmi@yahoo.com>
Datum: zondag, 22 januari 2023 05:41
Aan: freebsd-current <freebsd-current@freebsd.org>
Onderwerp: An idea for swap partition size vs. swap space size in use handling
> 
> I have boot media that are each set up to boot a variety
> of systems that have widely different RAM sizes, from
> 1 GiBytes to 64 GiBytes for the aarch64 examples of this.
> 
> This has lead to having multiple swap partitions of
> various sizes so that I can have total swap spaces that
> are somewhat under the recommended maximum sizes for the
> amount of RAM in each of those systems that a given media
> can boot.
> 
> It would be nice if I could have just one swap partition
> on a given boot media, one that is more than sufficient
> in size for all but the biggest RAM system --but to then
> be able to tell the system to just use up to the
> recommended swap space size and to ignore any extra swap
> space in the swap partition.
> 
> If such could be done, I'd no longer use multiple swap
> partitions at the same time in order to get to a desired
> total for the system at hand at the time.
> 
> Of course, that still leaves what to do when multiple
> swap partitions are enabled if such a "ignore what
> would be extra" mode was also enabled. As I'd not use
> such, I've no specific recommendations to make that
> would make any difference to my use.
> 
> ===
> Mark Millard
> marklmi at yahoo.com
> 
> Â 
> 
> 
> 


Hi Mark,

Do you mean you would like to be able to add a "size" parameter to the fstab swap line?

/dev/da0p1      none            swap    sw,size=1g              0       0

Another option I can think of is using the "gnop" geom provider. It has a -s parameter to set the size.

Regards,
Ronald.