warning: total configured swap (8960911 pages) exceeds maximum recommended amount (8243200 pages).

[RW]

On Thu, 17 Oct 2013 15:04:50 +0100 (BST)
Anton Shterenlikht wrote:

> I'm using a 72gb swap disk.
> I've 10gb RAM
> 
> I get this warning:
> 
> warning: total configured swap (8960911 pages) exceeds maximum
> recommended amount (8243200 pages). warning: increase kern.maxswzone
> or reduce amount of swap.
> 
> What is max. recommended amount based on?
> What is the danger of exceeding it?
> How should I increase kern.maxswzone?
> 
> # sysctl kern.maxswzone
> kern.maxswzone: 0
> # 
> 
> Do I set it to the total swap size?
> Where is kern.maxswzone described?

$ sysctl -d  kern.maxswzone
kern.maxswzone: Maximum memory for swap metadata

see also loader(8)

However setting kern.maxswzone can only be used to reduce the metadata size below the default, not increase it.

from swap_pager.c:

        n = cnt.v_page_count / 2;
        if (maxswzone && n > maxswzone / sizeof(struct swblock))
                n = maxswzone / sizeof(struct swblock);
        n2 = n;