> 
> **Possible Duplicate:**  
> 
> [Why does Red Hat Linux report less free memory on the system than is actually available?](https://serverfault.com/questions/9442/why-does-red-hat-linux-report-less-free-memory-on-the-system-than-is-actually-ava) 
> 
> 
> 

Hello,

I have a Dell R300 Ubuntu 9.10 box with 4GB of memory. All I'm running on there is haproxy, nagios and postfix yet there is ~2.7GB of memory being consumed. I've run ps and I can't get the sums to add up. Could anyone shed any light on where all the memory is being used?

Cheers,
Mark

```
$ sudo free -m
             total       used       free     shared    buffers     cached
Mem:          3957       2746       1211          0        169       2320
-/+ buffers/cache:        256       3701
Swap:         6212          0       6212

```

Sorry for pasting all of ps' output but I'm keen to get to the bottom of this.

```
$ sudo ps aux
[sudo] password for mark: 
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root         1  0.0  0.0  19320  1656 ?        Ss   May20   0:05 /sbin/init
root         2  0.0  0.0      0     0 ?        S<   May20   0:00 [kthreadd]
root         3  0.0  0.0      0     0 ?        S<   May20   0:00 [migration/0]
root         4  0.0  0.0      0     0 ?        S<   May20   0:16 [ksoftirqd/0]
root         5  0.0  0.0      0     0 ?        S<   May20   0:00 [watchdog/0]
root         6  0.0  0.0      0     0 ?        S<   May20   0:03 [migration/1]
root         7  0.0  0.0      0     0 ?        S<   May20   3:10 [ksoftirqd/1]
root         8  0.0  0.0      0     0 ?        S<   May20   0:00 [watchdog/1]
root         9  0.0  0.0      0     0 ?        S<   May20   0:00 [migration/2]
root        10  0.0  0.0      0     0 ?        S<   May20   0:19 [ksoftirqd/2]
root        11  0.0  0.0      0     0 ?        S<   May20   0:00 [watchdog/2]
root        12  0.0  0.0      0     0 ?        S<   May20   0:01 [migration/3]
root        13  0.0  0.0      0     0 ?        S<   May20   0:41 [ksoftirqd/3]
root        14  0.0  0.0      0     0 ?        S<   May20   0:00 [watchdog/3]
root        15  0.0  0.0      0     0 ?        S<   May20   0:03 [events/0]
root        16  0.0  0.0      0     0 ?        S<   May20   0:10 [events/1]
root        17  0.0  0.0      0     0 ?        S<   May20   0:08 [events/2]
root        18  0.0  0.0      0     0 ?        S<   May20   0:08 [events/3]
root        19  0.0  0.0      0     0 ?        S<   May20   0:00 [cpuset]
root        20  0.0  0.0      0     0 ?        S<   May20   0:00 [khelper]
root        21  0.0  0.0      0     0 ?        S<   May20   0:00 [netns]
root        22  0.0  0.0      0     0 ?        S<   May20   0:00 [async/mgr]
root        23  0.0  0.0      0     0 ?        S<   May20   0:00 [kintegrityd/0]
root        24  0.0  0.0      0     0 ?        S<   May20   0:00 [kintegrityd/1]
root        25  0.0  0.0      0     0 ?        S<   May20   0:00 [kintegrityd/2]
root        26  0.0  0.0      0     0 ?        S<   May20   0:00 [kintegrityd/3]
root        27  0.0  0.0      0     0 ?        S<   May20   0:00 [kblockd/0]
root        28  0.0  0.0      0     0 ?        S<   May20   0:01 [kblockd/1]
root        29  0.0  0.0      0     0 ?        S<   May20   0:04 [kblockd/2]
root        30  0.0  0.0      0     0 ?        S<   May20   0:02 [kblockd/3]
root        31  0.0  0.0      0     0 ?        S<   May20   0:00 [kacpid]
root        32  0.0  0.0      0     0 ?        S<   May20   0:00 [kacpi_notify]
root        33  0.0  0.0      0     0 ?        S<   May20   0:00 [kacpi_hotplug]
root        34  0.0  0.0      0     0 ?        S<   May20   0:00 [ata/0]
root        35  0.0  0.0      0     0 ?        S<   May20   0:00 [ata/1]
root        36  0.0  0.0      0     0 ?        S<   May20   0:00 [ata/2]
root        37  0.0  0.0      0     0 ?        S<   May20   0:00 [ata/3]
root        38  0.0  0.0      0     0 ?        S<   May20   0:00 [ata_aux]
root        39  0.0  0.0      0     0 ?        S<   May20   0:00 [ksuspend_usbd]
root        40  0.0  0.0      0     0 ?        S<   May20   0:00 [khubd]
root        41  0.0  0.0      0     0 ?        S<   May20   0:00 [kseriod]
root        42  0.0  0.0      0     0 ?        S<   May20   0:00 [kmmcd]
root        43  0.0  0.0      0     0 ?        S<   May20   0:00 [bluetooth]
root        44  0.0  0.0      0     0 ?        S    May20   0:00 [khungtaskd]
root        45  0.0  0.0      0     0 ?        S    May20   0:00 [pdflush]
root        46  0.0  0.0      0     0 ?        S    May20   0:09 [pdflush]
root        47  0.0  0.0      0     0 ?        S<   May20   0:00 [kswapd0]
root        48  0.0  0.0      0     0 ?        S<   May20   0:00 [aio/0]
root        49  0.0  0.0      0     0 ?        S<   May20   0:00 [aio/1]
root        50  0.0  0.0      0     0 ?        S<   May20   0:00 [aio/2]
root        51  0.0  0.0      0     0 ?        S<   May20   0:00 [aio/3]
root        52  0.0  0.0      0     0 ?        S<   May20   0:00 [ecryptfs-kthrea]
root        53  0.0  0.0      0     0 ?        S<   May20   0:00 [crypto/0]
root        54  0.0  0.0      0     0 ?        S<   May20   0:00 [crypto/1]
root        55  0.0  0.0      0     0 ?        S<   May20   0:00 [crypto/2]
root        56  0.0  0.0      0     0 ?        S<   May20   0:00 [crypto/3]
root        70  0.0  0.0      0     0 ?        S<   May20   0:00 [scsi_eh_0]
root        71  0.0  0.0      0     0 ?        S<   May20   0:00 [scsi_eh_1]
root        74  0.0  0.0      0     0 ?        S<   May20   0:00 [scsi_eh_2]
root        75  0.0  0.0      0     0 ?        S<   May20   0:00 [scsi_eh_3]
root        82  0.0  0.0      0     0 ?        S<   May20   0:00 [kstriped]
root        83  0.0  0.0      0     0 ?        S<   May20   0:00 [kmpathd/0]
root        84  0.0  0.0      0     0 ?        S<   May20   0:00 [kmpathd/1]
root        85  0.0  0.0      0     0 ?        S<   May20   0:00 [kmpathd/2]
root        86  0.0  0.0      0     0 ?        S<   May20   0:00 [kmpathd/3]
root        87  0.0  0.0      0     0 ?        S<   May20   0:00 [kmpath_handlerd]
root        88  0.0  0.0      0     0 ?        S<   May20   0:00 [ksnapd]
root        89  0.0  0.0      0     0 ?        S<   May20   0:00 [kondemand/0]
root        90  0.0  0.0      0     0 ?        S<   May20   0:00 [kondemand/1]
root        91  0.0  0.0      0     0 ?        S<   May20   0:00 [kondemand/2]
root        92  0.0  0.0      0     0 ?        S<   May20   0:00 [kondemand/3]
root        93  0.0  0.0      0     0 ?        S<   May20   0:00 [kconservative/0]
root        94  0.0  0.0      0     0 ?        S<   May20   0:00 [kconservative/1]
root        95  0.0  0.0      0     0 ?        S<   May20   0:00 [kconservative/2]
root        96  0.0  0.0      0     0 ?        S<   May20   0:00 [kconservative/3]
root        97  0.0  0.0      0     0 ?        S<   May20   0:00 [krfcommd]
root       315  0.0  0.0      0     0 ?        S<   May20   0:09 [mpt_poll_0]
root       317  0.0  0.0      0     0 ?        S<   May20   0:00 [mpt/0]
root       547  0.0  0.0      0     0 ?        S<   May20   0:00 [scsi_eh_4]
root       587  0.0  0.0      0     0 ?        S<   May20   0:11 [kjournald2]
root       636  0.0  0.0  12748   860 ?        S    May20   0:00 upstart-udev-bridge --daemon
root       657  0.0  0.0  17064   924 ?        S<s  May20   0:00 udevd --daemon
root       666  0.0  0.0   8192   612 ?        Ss   May20   0:00 dd bs=1 if=/proc/kmsg of=/var/run/rsyslog/kmsg
root       774  0.0  0.0  17060   888 ?        S<   May20   0:00 udevd --daemon
root       775  0.0  0.0  17060   888 ?        S<   May20   0:00 udevd --daemon
syslog     825  0.0  0.0 191696  1988 ?        Sl   May20   0:31 rsyslogd -c4
root       839  0.0  0.0      0     0 ?        S<   May20   0:00 [edac-poller]
root       870  0.0  0.0      0     0 ?        S<   May20   0:00 [kpsmoused]
root      1006  0.0  0.0   5988   604 tty4     Ss+  May20   0:00 /sbin/getty -8 38400 tty4
root      1008  0.0  0.0   5988   604 tty5     Ss+  May20   0:00 /sbin/getty -8 38400 tty5
root      1015  0.0  0.0   5988   604 tty2     Ss+  May20   0:00 /sbin/getty -8 38400 tty2
root      1016  0.0  0.0   5988   608 tty3     Ss+  May20   0:00 /sbin/getty -8 38400 tty3
root      1018  0.0  0.0   5988   604 tty6     Ss+  May20   0:00 /sbin/getty -8 38400 tty6
daemon    1025  0.0  0.0  16512   472 ?        Ss   May20   0:00 atd
root      1026  0.0  0.0  18708  1000 ?        Ss   May20   0:03 cron
root      1052  0.0  0.0  49072  1252 ?        Ss   May20   0:25 /usr/sbin/sshd
root      1084  0.0  0.0   5988   604 tty1     Ss+  May20   0:00 /sbin/getty -8 38400 tty1
root      6320  0.0  0.0  19440   956 ?        Ss   May21   0:00 /usr/sbin/xinetd -pidfile /var/run/xinetd.pid -stayalive -inetd_compat -inetd_ipv6
nagios    8197  0.0  0.0  27452  1696 ?        SNs  May21   2:57 /usr/sbin/nagios3 -d /etc/nagios3/nagios.cfg
root     10882  0.1  0.0  70280  3104 ?        Ss   10:30   0:00 sshd: mark [priv]
mark     10934  0.0  0.0  70432  1776 ?        S    10:30   0:00 sshd: mark@pts/0 
mark     10935  1.4  0.1  21572  4336 pts/0    Ss   10:30   0:00 -bash
root     10953  1.0  0.0  15164  1136 pts/0    R+   10:30   0:00 ps aux
haproxy  12738  0.0  0.0  17208   992 ?        Ss   Jun08   0:49 /usr/sbin/haproxy -f /etc/haproxy/haproxy.cfg
root     23953  0.0  0.0  37012  2192 ?        Ss   Jun04   0:03 /usr/lib/postfix/master
postfix  23955  0.0  0.0  39232  2356 ?        S    Jun04   0:00 qmgr -l -t fifo -u
postfix  32603  0.0  0.0  39072  2132 ?        S    09:05   0:00 pickup -l -t fifo -u -c

```

Here's meminfo:

```
$ cat /proc/meminfo
MemTotal:        4052852 kB
MemFree:         1240488 kB
Buffers:          173172 kB
Cached:          2376420 kB
SwapCached:            0 kB
Active:          1479288 kB
Inactive:        1081876 kB
Active(anon):      11792 kB
Inactive(anon):        0 kB
Active(file):    1467496 kB
Inactive(file):  1081876 kB
Unevictable:           0 kB
Mlocked:               0 kB
SwapTotal:       6361700 kB
SwapFree:        6361700 kB
Dirty:                44 kB
Writeback:             0 kB
AnonPages:         11568 kB
Mapped:             5844 kB
Slab:             155032 kB
SReclaimable:     145804 kB
SUnreclaim:         9228 kB
PageTables:         1592 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:     8388124 kB
Committed_AS:      51732 kB
VmallocTotal:   34359738367 kB
VmallocUsed:      282604 kB
VmallocChunk:   34359453499 kB
HugePages_Total:       0
HugePages_Free:        0
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB
DirectMap4k:        6784 kB
DirectMap2M:     4182016 kB

```

Here's slabinfo:

```
$ cat /proc/slabinfo
slabinfo - version: 2.1
# name            <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab> : tunables <limit> <batchcount> <sharedfactor> : slabdata <active_slabs> <num_slabs> <sharedavail>
ip6_dst_cache         50     50    320   25    2 : tunables    0    0    0 : slabdata      2      2      0
UDPLITEv6              0      0    960   17    4 : tunables    0    0    0 : slabdata      0      0      0
UDPv6                 68     68    960   17    4 : tunables    0    0    0 : slabdata      4      4      0
tw_sock_TCPv6          0      0    320   25    2 : tunables    0    0    0 : slabdata      0      0      0
TCPv6                 72     72   1792   18    8 : tunables    0    0    0 : slabdata      4      4      0
dm_raid1_read_record      0      0   1064   30    8 : tunables    0    0    0 : slabdata      0      0      0
kcopyd_job             0      0    368   22    2 : tunables    0    0    0 : slabdata      0      0      0
dm_uevent              0      0   2608   12    8 : tunables    0    0    0 : slabdata      0      0      0
dm_rq_target_io        0      0    376   21    2 : tunables    0    0    0 : slabdata      0      0      0
uhci_urb_priv          0      0     56   73    1 : tunables    0    0    0 : slabdata      0      0      0
cfq_queue              0      0    168   24    1 : tunables    0    0    0 : slabdata      0      0      0
mqueue_inode_cache     18     18    896   18    4 : tunables    0    0    0 : slabdata      1      1      0
fuse_request           0      0    632   25    4 : tunables    0    0    0 : slabdata      0      0      0
fuse_inode             0      0    768   21    4 : tunables    0    0    0 : slabdata      0      0      0
ecryptfs_inode_cache      0      0   1024   16    4 : tunables    0    0    0 : slabdata      0      0      0
hugetlbfs_inode_cache     26     26    608   26    4 : tunables    0    0    0 : slabdata      1      1      0
journal_handle       680    680     24  170    1 : tunables    0    0    0 : slabdata      4      4      0
journal_head         144    144    112   36    1 : tunables    0    0    0 : slabdata      4      4      0
revoke_table         256    256     16  256    1 : tunables    0    0    0 : slabdata      1      1      0
revoke_record        512    512     32  128    1 : tunables    0    0    0 : slabdata      4      4      0
ext4_inode_cache   53306  53424    888   18    4 : tunables    0    0    0 : slabdata   2968   2968      0
ext4_free_block_extents    292    292     56   73    1 : tunables    0    0    0 : slabdata      4      4      0
ext4_alloc_context    112    112    144   28    1 : tunables    0    0    0 : slabdata      4      4      0
ext4_prealloc_space    156    156    104   39    1 : tunables    0    0    0 : slabdata      4      4      0
ext4_system_zone       0      0     40  102    1 : tunables    0    0    0 : slabdata      0      0      0
ext2_inode_cache       0      0    776   21    4 : tunables    0    0    0 : slabdata      0      0      0
ext3_inode_cache       0      0    784   20    4 : tunables    0    0    0 : slabdata      0      0      0
ext3_xattr             0      0     88   46    1 : tunables    0    0    0 : slabdata      0      0      0
dquot                  0      0    256   16    1 : tunables    0    0    0 : slabdata      0      0      0
shmem_inode_cache    606    620    800   20    4 : tunables    0    0    0 : slabdata     31     31      0
pid_namespace          0      0   2112   15    8 : tunables    0    0    0 : slabdata      0      0      0
UDP-Lite               0      0    832   19    4 : tunables    0    0    0 : slabdata      0      0      0
RAW                  183    210    768   21    4 : tunables    0    0    0 : slabdata     10     10      0
UDP                   76     76    832   19    4 : tunables    0    0    0 : slabdata      4      4      0
tw_sock_TCP           80     80    256   16    1 : tunables    0    0    0 : slabdata      5      5      0
TCP                   81    114   1664   19    8 : tunables    0    0    0 : slabdata      6      6      0
blkdev_integrity     144    144    112   36    1 : tunables    0    0    0 : slabdata      4      4      0
blkdev_queue          64     64   2024   16    8 : tunables    0    0    0 : slabdata      4      4      0
blkdev_requests      120    120    336   24    2 : tunables    0    0    0 : slabdata      5      5      0
fsnotify_event       156    156    104   39    1 : tunables    0    0    0 : slabdata      4      4      0
bip-256                7      7   4224    7    8 : tunables    0    0    0 : slabdata      1      1      0
bip-128                0      0   2176   15    8 : tunables    0    0    0 : slabdata      0      0      0
bip-64                 0      0   1152   28    8 : tunables    0    0    0 : slabdata      0      0      0
bip-16                84     84    384   21    2 : tunables    0    0    0 : slabdata      4      4      0
sock_inode_cache     224    276    704   23    4 : tunables    0    0    0 : slabdata     12     12      0
file_lock_cache       88     88    184   22    1 : tunables    0    0    0 : slabdata      4      4      0
net_namespace          0      0   1920   17    8 : tunables    0    0    0 : slabdata      0      0      0
Acpi-ParseExt        640    672     72   56    1 : tunables    0    0    0 : slabdata     12     12      0
taskstats             48     48    328   24    2 : tunables    0    0    0 : slabdata      2      2      0
proc_inode_cache    1613   1750    640   25    4 : tunables    0    0    0 : slabdata     70     70      0
sigqueue             100    100    160   25    1 : tunables    0    0    0 : slabdata      4      4      0
radix_tree_node    22443  22475    560   29    4 : tunables    0    0    0 : slabdata    775    775      0
bdev_cache            72     72    896   18    4 : tunables    0    0    0 : slabdata      4      4      0
sysfs_dir_cache     9866   9894     80   51    1 : tunables    0    0    0 : slabdata    194    194      0
inode_cache         2268   2268    592   27    4 : tunables    0    0    0 : slabdata     84     84      0
dentry            285907 286062    192   21    1 : tunables    0    0    0 : slabdata  13622  13622      0
buffer_head       256447 257472    112   36    1 : tunables    0    0    0 : slabdata   7152   7152      0
vm_area_struct      1469   1541    176   23    1 : tunables    0    0    0 : slabdata     67     67      0
mm_struct             82     95    832   19    4 : tunables    0    0    0 : slabdata      5      5      0
files_cache          104    161    704   23    4 : tunables    0    0    0 : slabdata      7      7      0
signal_cache         163    187    960   17    4 : tunables    0    0    0 : slabdata     11     11      0
sighand_cache        145    165   2112   15    8 : tunables    0    0    0 : slabdata     11     11      0
task_xstate          118    140    576   28    4 : tunables    0    0    0 : slabdata      5      5      0
task_struct          128    165   5808    5    8 : tunables    0    0    0 : slabdata     33     33      0
anon_vma             731    896     32  128    1 : tunables    0    0    0 : slabdata      7      7      0
shared_policy_node     85     85     48   85    1 : tunables    0    0    0 : slabdata      1      1      0
numa_policy          170    170     24  170    1 : tunables    0    0    0 : slabdata      1      1      0
idr_layer_cache      240    240    544   30    4 : tunables    0    0    0 : slabdata      8      8      0
kmalloc-8192          27     32   8192    4    8 : tunables    0    0    0 : slabdata      8      8      0
kmalloc-4096         291    344   4096    8    8 : tunables    0    0    0 : slabdata     43     43      0
kmalloc-2048         225    240   2048   16    8 : tunables    0    0    0 : slabdata     15     15      0
kmalloc-1024         366    432   1024   16    4 : tunables    0    0    0 : slabdata     27     27      0
kmalloc-512          536    544    512   16    2 : tunables    0    0    0 : slabdata     34     34      0
kmalloc-256          406    528    256   16    1 : tunables    0    0    0 : slabdata     33     33      0
kmalloc-128          503    576    128   32    1 : tunables    0    0    0 : slabdata     18     18      0
kmalloc-64          3467   3712     64   64    1 : tunables    0    0    0 : slabdata     58     58      0
kmalloc-32          1520   1920     32  128    1 : tunables    0    0    0 : slabdata     15     15      0
kmalloc-16          3547   3840     16  256    1 : tunables    0    0    0 : slabdata     15     15      0
kmalloc-8           4607   4608      8  512    1 : tunables    0    0    0 : slabdata      9      9      0
kmalloc-192         4620   5313    192   21    1 : tunables    0    0    0 : slabdata    253    253      0
kmalloc-96          1780   1848     96   42    1 : tunables    0    0    0 : slabdata     44     44      0
kmem_cache_node        0      0     64   64    1 : tunables    0    0    0 : slabdata      0      0      0

```