mlist via checkmk-en
2017-12-13 13:23:23 UTC
Hy guys
I would like your opinion about a memory alert related to a linux host:
I have a linux server running Oracle and, with the check_MK default thresholds, I get:
CRIT - RAM used: 6.55 GB of 31.35 GB, Swap used: 895.76 MB of 2.00 GB, Total virtual memory used: 7.42 GB of 33.35 GB (22.3%), Shared memory: 14.63 GB (46.7% of RAM, warn/crit at 20.0%/30.0%)CRIT,
Effectively the /proc/meminfo does report:
[***@radora1 ~]# cat /proc/meminfo
MemTotal: 32872552 kB
MemFree: 1833276 kB
Buffers: 586884 kB
Cached: 22609092 kB
SwapCached: 44060 kB
Active: 19674812 kB
Inactive: 7460500 kB
Active(anon): 16988784 kB
Inactive(anon): 2353340 kB
Active(file): 2686028 kB
Inactive(file): 5107160 kB
Unevictable: 1541296 kB
Mlocked: 492724 kB
SwapTotal: 2097144 kB
SwapFree: 1179888 kB
Dirty: 3136 kB
Writeback: 0 kB
AnonPages: 5436636 kB
Mapped: 11630920 kB
Shmem: 15340328 kB
Slab: 1493928 kB
SReclaimable: 934316 kB
SUnreclaim: 559612 kB
KernelStack: 7752 kB
PageTables: 548052 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 18533420 kB
Committed_AS: 25169800 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 282264 kB
VmallocChunk: 34359413760 kB
HardwareCorrupted: 0 kB
AnonHugePages: 1820672 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
DirectMap4k: 8192 kB
DirectMap2M: 2088960 kB
DirectMap1G: 31457280 kB
This is the output of free
[***@myserver ~]# free -m
total used free shared buffers cached
Mem: 32102 30327 1774 0 573 22066
-/+ buffers/cache: 7688 24413
Swap: 2047 895 1152
The question is:
why, in your opinion check_MK did configure warn/crit at 20.0%/30.0%? I mean: I know I could change threshold but, because I suppose that check_MK developers know very well linux, I suspect I'm missing some good knowledge about shared memory on linux and, before to do that (or completely ignore the alarm), I would know if it could be really a problem or not the fact that the shared memory is above 30% of physical ram. What do you think?
I would like your opinion about a memory alert related to a linux host:
I have a linux server running Oracle and, with the check_MK default thresholds, I get:
CRIT - RAM used: 6.55 GB of 31.35 GB, Swap used: 895.76 MB of 2.00 GB, Total virtual memory used: 7.42 GB of 33.35 GB (22.3%), Shared memory: 14.63 GB (46.7% of RAM, warn/crit at 20.0%/30.0%)CRIT,
Effectively the /proc/meminfo does report:
[***@radora1 ~]# cat /proc/meminfo
MemTotal: 32872552 kB
MemFree: 1833276 kB
Buffers: 586884 kB
Cached: 22609092 kB
SwapCached: 44060 kB
Active: 19674812 kB
Inactive: 7460500 kB
Active(anon): 16988784 kB
Inactive(anon): 2353340 kB
Active(file): 2686028 kB
Inactive(file): 5107160 kB
Unevictable: 1541296 kB
Mlocked: 492724 kB
SwapTotal: 2097144 kB
SwapFree: 1179888 kB
Dirty: 3136 kB
Writeback: 0 kB
AnonPages: 5436636 kB
Mapped: 11630920 kB
Shmem: 15340328 kB
Slab: 1493928 kB
SReclaimable: 934316 kB
SUnreclaim: 559612 kB
KernelStack: 7752 kB
PageTables: 548052 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 18533420 kB
Committed_AS: 25169800 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 282264 kB
VmallocChunk: 34359413760 kB
HardwareCorrupted: 0 kB
AnonHugePages: 1820672 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
DirectMap4k: 8192 kB
DirectMap2M: 2088960 kB
DirectMap1G: 31457280 kB
This is the output of free
[***@myserver ~]# free -m
total used free shared buffers cached
Mem: 32102 30327 1774 0 573 22066
-/+ buffers/cache: 7688 24413
Swap: 2047 895 1152
The question is:
why, in your opinion check_MK did configure warn/crit at 20.0%/30.0%? I mean: I know I could change threshold but, because I suppose that check_MK developers know very well linux, I suspect I'm missing some good knowledge about shared memory on linux and, before to do that (or completely ignore the alarm), I would know if it could be really a problem or not the fact that the shared memory is above 30% of physical ram. What do you think?