Max size of one swap slice
max at love2party.net
Tue Aug 5 17:19:36 UTC 2008
On Tuesday 05 August 2008 17:39:11 Lin Jui-Nan Eric wrote:
> Recently we found that we can only allocate 32GB for one swap slice.
> Does there is any sysctl oid or any kernel option to increase it? Why
> we have this restriction?
this is a consequence of the data structure used to manage swap space. See
sys/blist.h for details. It *seems* that you *might* be able to increase the
coverage by decreasing BLIST_META_RADIX, but that's from a quick glance and
most certainly not a good idea.
However, the blist is a abstract enough API so that you can likely replace it
with something that supports 64bit addresses (and thus 512*2^64 bytes of swap
space per device) ... but I don't see why you'd want to do something like
this. Remember that you need memory to manage your swap space as well!
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