Hi, Since we upgraded our server to 3.6, it runs out of memory. This is what I can find in syslog (multiple similar entries): Dec 7 19:52:42 gcclo77 kernel: Out of Memory: Killed process 31375 (nagios). Dec 7 19:52:43 gcclo77 kernel: Mem-info: Dec 7 19:52:43 gcclo77 kernel: Zone:DMA freepages: 2927 min: 0 low: 0 high: 0 Dec 7 19:52:43 gcclo77 kernel: Zone:Normal freepages: 737 min: 766 low: 4031 high: 5791 Dec 7 19:52:43 gcclo77 kernel: Zone:HighMem freepages: 126 min: 255 low: 510 high: 765 Dec 7 19:52:43 gcclo77 kernel: Free pages: 3790 ( 126 HighMem) Dec 7 19:52:43 gcclo77 kernel: ( Active: 162420/241, inactive_laundry: 0, inactive_clean: 0, free: 3790 ) Dec 7 19:52:43 gcclo77 kernel: aa:0 ac:0 id:0 il:0 ic:0 fr:2927 Dec 7 19:52:43 gcclo77 kernel: aa:157445 ac:1554 id:301 il:0 ic:0 fr:737 Dec 7 19:52:43 gcclo77 kernel: aa:2791 ac:569 id:1 il:0 ic:0 fr:126 Dec 7 19:52:43 gcclo77 kernel: 3*4kB 2*8kB 4*16kB 3*32kB 4*64kB 2*128kB 1*256kB 1*512kB 0*1024kB 1*2048kB 2*4096kB = 11708kB) Dec 7 19:52:43 gcclo77 kernel: 49*4kB 0*8kB 0*16kB 0*32kB 1*64kB 1*128kB 0*256kB 1*512kB 0*1024kB 1*2048kB 0*4096kB = 2948kB) Dec 7 19:52:43 gcclo77 kernel: 0*4kB 1*8kB 1*16kB 1*32kB 1*64kB 1*128kB 1*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 504kB) Dec 7 19:52:44 gcclo77 kernel: Swap cache: add 861742, delete 858950, find 7617227/7652707, race 0+36 Dec 7 19:52:44 gcclo77 kernel: 13082 pages of slabcache Dec 7 19:52:44 gcclo77 kernel: 9852 pages of kernel stacks Dec 7 19:52:44 gcclo77 kernel: 17191 lowmem pagetables, 28807 highmem pagetables Dec 7 19:52:44 gcclo77 kernel: 32 bounce buffer pages, 32 are on the emergency list Dec 7 19:52:44 gcclo77 kernel: Free swap: 0kB Dec 7 19:52:44 gcclo77 kernel: 262138 pages of RAM Dec 7 19:52:44 gcclo77 kernel: 32762 pages of HIGHMEM Dec 7 19:52:44 gcclo77 kernel: 5784 reserved pages Dec 7 19:52:44 gcclo77 kernel: 7450 pages shared Dec 7 19:52:45 gcclo77 kernel: 2792 pages swap cached Dec 7 19:52:45 gcclo77 kernel: Out of Memory: Killed process 31401 (nagios). Dec 7 19:52:45 gcclo77 kernel: Mem-info: Dec 7 19:52:45 gcclo77 kernel: Zone:DMA freepages: 2927 min: 0 low: 0 high: 0 Dec 7 19:52:45 gcclo77 kernel: Zone:Normal freepages: 753 min: 766 low: 4031 high: 5791 Dec 7 19:52:45 gcclo77 kernel: Zone:HighMem freepages: 126 min: 255 low: 510 high: 765 Dec 7 19:52:45 gcclo77 kernel: Free pages: 3806 ( 126 HighMem) Dec 7 19:52:45 gcclo77 kernel: ( Active: 162136/453, inactive_laundry: 72, inactive_clean: 0, free: 3806 ) Dec 7 19:52:45 gcclo77 kernel: aa:0 ac:0 id:0 il:0 ic:0 fr:2927 Dec 7 19:52:45 gcclo77 kernel: aa:157502 ac:1554 id:172 il:72 ic:0 fr:753 Dec 7 19:52:46 gcclo77 kernel: aa:2666 ac:439 id:256 il:0 ic:0 fr:126 Dec 7 19:52:46 gcclo77 kernel: 3*4kB 2*8kB 4*16kB 3*32kB 4*64kB 2*128kB 1*256kB 1*512kB 0*1024kB 1*2048kB 2*4096kB = 11708kB) Dec 7 19:52:46 gcclo77 kernel: 65*4kB 0*8kB 0*16kB 0*32kB 1*64kB 1*128kB 0*256kB 1*512kB 0*1024kB 1*2048kB 0*4096kB = 3012kB) Dec 7 19:52:46 gcclo77 kernel: 0*4kB 1*8kB 1*16kB 1*32kB 1*64kB 1*128kB 1*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 504kB) Dec 7 19:52:46 gcclo77 kernel: Swap cache: add 861742, delete 858950, find 7617227/7652707, race 0+36 Dec 7 19:52:46 gcclo77 kernel: 13082 pages of slabcache Dec 7 19:52:46 gcclo77 kernel: 9852 pages of kernel stacks Dec 7 19:52:46 gcclo77 kernel: 17178 lowmem pagetables, 28807 highmem pagetables Dec 7 19:52:46 gcclo77 kernel: 32 bounce buffer pages, 32 are on the emergency list Dec 7 19:52:47 gcclo77 kernel: Free swap: 0kB Dec 7 19:52:47 gcclo77 kernel: 262138 pages of RAM Dec 7 19:52:47 gcclo77 kernel: 32762 pages of HIGHMEM Dec 7 19:52:47 gcclo77 kernel: 5784 reserved pages Dec 7 19:52:47 gcclo77 kernel: 7020 pages shared Dec 7 19:52:47 gcclo77 kernel: 2792 pages swap cached Anyone any ideas as to what causes this? Thanks! Tom