Decided not to wait and try it out immediately. Adding swap space seems to have solved by issue. The zone that we had to stop earlier could be started again now, with all its applications.

Strange thing is that even after starting that zone, there is no actual swap space used!

Code:

# swap -l
swapfile             dev  swaplo blocks   free
/dev/zvol/dsk/rpool/swap 181,2       8 4194296 4194296
/dev/zvol/dsk/rpool/swap1 181,3       8 67108856 67108856
#

See? blocks == free...

Is Solaris doing something like "eager ahead of time allocation", in the anticipation that it might need that memory in the future? Otherwise I have no explanation for this myself...

Maarten

---------- Post updated at 16:41 ---------- Previous update was at 16:22 ----------

Actually I just added a second swap device (swap -l now has 2 lines output). Seemed to be the less risky option.

The point for me is that I don't see any memory reservations that would exceed my physical RAM. Well, actually, that's not entirely true. Going back to the "memstat | mdb" output:

Code:

# echo ::memstat | mdb -k
Page Summary                Pages                MB  %Tot
------------     ----------------  ----------------  ----
Kernel                     834125              3258    4%
ZFS File Data             2074033              8101   11%
Anon                      9626639             37604   51%
Exec and libs              490864              1917    3%
Page cache                 281713              1100    1%
Free (cachelist)           912592              3564    5%
Free (freelist)           4650073             18164   25%

Total                    18870039             73711
Physical                 18362748             71729

I see that Total is larger than Physical. I just don't understand why that would be the case. Couldn't Solaris "make this fit" by reducing the freelist a tiny bit in size? Why does the above list of zfs/anon/exec/page/freecache/freelist have to add up to something that exceeds physical RAM size?

Maarten