I noticed that meminfo - Buffers occupies significant amount of RAM on some servers in my work environment.
I'd like to know what is exactly is "Buffers" and why it takes that much amount of RAM. Some quick googling indicate that "Buffers" are Cached equivalent of non-file-data, however it's difficult to explain why "Buffers" takes 10G RAM - while Cached takes less than 7X of that.
This example data is a build server. Several people use it to build some large projects, e.g. Android. There is no (non-trivial) service running on it. It's not heavily used. When taking /proc/meminfo data, it is idle.
lsb_release -a
LSB Version: core-2.0-amd64:core-2.0-noarch:core-3.0-amd64:core-3.0-noarch:core-3.1-amd64:core-3.1-noarch:core-3.2-amd64:core-3.2-noarch:core-4.0-amd64:core-4.0-noarch
Distributor ID: Ubuntu
Description: Ubuntu 11.04
Release: 11.04
Codename: natty
cat /proc/meminfo
MemTotal: 99166244 kB
MemFree: 468604 kB
Buffers: 10315020 kB
Cached: 68312620 kB
SwapCached: 41364 kB
Active: 42604444 kB
Inactive: 40784816 kB
Active(anon): 4424120 kB
Inactive(anon): 421392 kB
Active(file): 38180324 kB
Inactive(file): 40363424 kB
Unevictable: 0 kB
Mlocked: 0 kB
SwapTotal: 2008120 kB
SwapFree: 1120892 kB
Dirty: 4872 kB
Writeback: 0 kB
AnonPages: 4733328 kB
Mapped: 116032 kB
Shmem: 83812 kB
Slab: 13248832 kB
SReclaimable: 13047840 kB
SUnreclaim: 200992 kB
KernelStack: 14064 kB
PageTables: 147124 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 51591240 kB
Committed_AS: 16135556 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 535184 kB
VmallocChunk: 34359200236 kB
HardwareCorrupted: 0 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
DirectMap4k: 669696 kB
DirectMap2M: 24479744 kB
DirectMap1G: 75497472 kB
