reguarding swap page outs problems

[Suporte Dsgx]

Oct 20 01:21:25 vds1 /kernel: swap_pager: I/O error - pageout failed; blkno 93848,size 4096, error 22
Oct 20 01:21:25 vds1 /kernel: swap_pager: I/O error - pageout failed; blkno 133328,size 8192, error 22
Oct 20 01:21:25 vds1 /kernel: swap_pager: I/O error - pageout failed; blkno 94304,size 4096, error 22
Oct 20 01:21:25 vds1 /kernel: swap_pager: I/O error - pageout failed; blkno 94336,size 4096, error 22
Oct 20 01:21:25 vds1 /kernel: swap_pager: I/O error - pageout failed; blkno 94488,size 4096, error 22
Oct 20 01:21:25 vds1 /kernel: swap_pager: I/O error - pageout failed; blkno 94832,size 4096, error 22
Oct 20 01:21:25 vds1 /kernel: swap_pager: I/O error - pageout failed; blkno 95000,size 4096, error 22
Oct 20 01:21:25 vds1 /kernel: swap_pager: I/O error - pageout failed; blkno 34376,size 4096, error 22
Oct 20 01:21:25 vds1 /kernel: swap_pager: I/O error - pageout failed; blkno 95016,size 4096, error 22
Oct 20 01:21:25 vds1 /kernel: swap_pager: I/O error - pageout failed; blkno 95096,size 4096, error 22
Oct 20 01:21:25 vds1 /kernel: swap_pager: I/O error - pageout failed; blkno 133512,size 8192, error 22

---
im getting this all the time and the load of the ded goes badly high like 300/400 then goes down from nothing cause it found a avaiable peace of ram .. what this could be ? probably in the paritcion of swap ?
this r the specs of the time of the problem
Swap: 1976M Total, 421M Used, 1555M Free, 21% Inuse
Mem: 572M Active, 132M Inact, 164M Wired, 27M Cache, 110M Buf, 90M Free
Device          1K-blocks     Used    Avail Capacity  Type
/dev/ad0s1b        999768   273648   726120    27%    Interleaved
/dev/rvn0b        1023872   157548   866324    15%    Interleaved
Total             2023640   431196  1592444    21%