Linux中神秘的内存使用

我们有一些运行在Microsoft Windows 2012 Server（Hypervisor）上的64位Linux机器（RHEL6），也有同样的问题。 这些Linux访客服务器在MS Windows云（Hyper-V）中运行，每个服务器有16个主机服务器，每个RAM有256 GB的RAM。

他们从下面的内存使用开始：

# free -m total used free shared buffers cached Mem: 48259 653 47606 0 19 106 -/+ buffers/cache: 527 47732 Swap: 13999 0 13999 # cat /proc/meminfo MemTotal: 49418204 kB MemFree: 48749868 kB Buffers: 20080 kB Cached: 108564 kB SwapCached: 0 kB Active: 149652 kB Inactive: 98856 kB Active(anon): 120124 kB Inactive(anon): 1884 kB Active(file): 29528 kB Inactive(file): 96972 kB Unevictable: 4 kB Mlocked: 4 kB SwapTotal: 14335992 kB SwapFree: 14335992 kB Dirty: 788 kB Writeback: 0 kB AnonPages: 122196 kB Mapped: 39844 kB Shmem: 2132 kB Slab: 51832 kB SReclaimable: 14696 kB SUnreclaim: 37136 kB KernelStack: 5656 kB PageTables: 15840 kB NFS_Unstable: 0 kB Bounce: 0 kB WritebackTmp: 0 kB CommitLimit: 39045092 kB Committed_AS: 490856 kB VmallocTotal: 34359738367 kB VmallocUsed: 131964 kB VmallocChunk: 34359602252 kB HardwareCorrupted: 0 kB AnonHugePages: 28672 kB HugePages_Total: 0 HugePages_Free: 0 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 2048 kB DirectMap4k: 8128 kB DirectMap2M: 50323456 kB 

（RES指令）

 # top top - 11:26:52 up 1 min, 1 user, load average: 1.71, 0.73, 0.27 Tasks: 609 total, 1 running, 608 sleeping, 0 stopped, 0 zombie Cpu(s): 0.0%us, 0.1%sy, 0.0%ni, 99.8%id, 0.0%wa, 0.1%hi, 0.0%si, 0.0%st Mem: 49418204k total, 674472k used, 48743732k free, 20472k buffers Swap: 14335992k total, 0k used, 14335992k free, 111720k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 1859 root 20 0 103m 28m 5784 S 0.0 0.1 0:00.85 Xvnc 2037 root 20 0 508m 25m 8876 S 0.7 0.1 0:01.18 gnome-settings- 2064 root 20 0 373m 17m 12m S 0.0 0.0 0:01.11 nautilus 2141 root 20 0 464m 16m 12m S 0.0 0.0 0:00.14 clock-applet 2063 root 20 0 319m 14m 10m S 0.0 0.0 0:00.28 gnome-panel 2082 root 20 0 307m 12m 9100 S 0.0 0.0 0:00.11 nm-applet 2139 root 20 0 381m 12m 9748 S 0.0 0.0 0:00.08 gdm-user-switch 2093 root 20 0 442m 11m 9104 S 0.0 0.0 0:00.13 gnome-volume-co 2116 root 20 0 299m 11m 9476 S 0.0 0.0 0:00.10 wnck-applet 2118 root 20 0 307m 11m 8768 S 0.0 0.0 0:00.06 trashapplet ... 

6分钟后，内存被一个未知的进程或内核消耗：

• Docker + Apache，内存使用情况如何工作？
• 一个RAM模块中的坏字节/正在使用的RAM块区域
• 清除/刷新高速caching的内存
• 低内存应用优先级
• 为什么我的服务器使用这么多的内存？

 uptime ; free -m 11:31:52 up 6 min, 1 user, load average: 1.05, 0.93, 0.47 total used free shared buffers cached Mem: 48259 25296 22963 0 21 160 -/+ buffers/cache: 25115 23144 Swap: 13999 0 13999 ]# cat /proc/meminfo MemTotal: 49418204 kB MemFree: 23514240 kB Buffers: 21600 kB Cached: 164428 kB SwapCached: 0 kB Active: 210768 kB Inactive: 108108 kB Active(anon): 133036 kB Inactive(anon): 2332 kB Active(file): 77732 kB Inactive(file): 105776 kB Unevictable: 8 kB Mlocked: 8 kB SwapTotal: 14335992 kB SwapFree: 14335992 kB Dirty: 0 kB Writeback: 0 kB AnonPages: 132892 kB Mapped: 41976 kB Shmem: 2516 kB Slab: 52624 kB SReclaimable: 17628 kB SUnreclaim: 34996 kB KernelStack: 5752 kB PageTables: 15756 kB NFS_Unstable: 0 kB Bounce: 0 kB WritebackTmp: 0 kB CommitLimit: 39045092 kB Committed_AS: 654848 kB VmallocTotal: 34359738367 kB VmallocUsed: 131964 kB VmallocChunk: 34359602252 kB HardwareCorrupted: 0 kB AnonHugePages: 45056 kB HugePages_Total: 0 HugePages_Free: 0 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 2048 kB DirectMap4k: 8128 kB DirectMap2M: 50323456 kB 

（RES指令）

 # top top - 11:32:45 up 7 min, 1 user, load average: 1.02, 0.94, 0.50 Tasks: 607 total, 1 running, 606 sleeping, 0 stopped, 0 zombie Cpu(s): 0.1%us, 0.1%sy, 0.0%ni, 99.7%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 49418204k total, 25904096k used, 23514108k free, 21600k buffers Swap: 14335992k total, 0k used, 14335992k free, 164428k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 1859 root 20 0 103m 28m 6176 S 0.0 0.1 0:00.87 Xvnc 2037 root 20 0 508m 25m 8916 S 0.0 0.1 0:01.19 gnome-settings- 2064 root 20 0 373m 17m 12m S 0.0 0.0 0:01.61 nautilus 2141 root 20 0 464m 16m 12m S 0.0 0.0 0:00.15 clock-applet 2063 root 20 0 319m 14m 10m S 0.0 0.0 0:00.29 gnome-panel 1788 root 20 0 779m 13m 5808 S 0.0 0.0 0:00.18 scxcimserver 2082 root 20 0 307m 12m 9100 S 0.0 0.0 0:00.11 nm-applet 2139 root 20 0 381m 12m 9748 S 0.0 0.0 0:00.08 gdm-user-switch 2093 root 20 0 442m 11m 9104 S 0.0 0.0 0:00.13 gnome-volume-co 2116 root 20 0 299m 11m 9476 S 0.0 0.0 0:00.10 wnck-applet ... 

以ps表示的RSS内存总和约为388：

 # ps aux | awk '{sum+=$6} END {print sum / 1024}' 387.898 

还有什么可以检查什么是消费内存？