Ubuntu não reconhece ram completo

Question

Tenho 32 GB de RAM instalados no meu Dell Optiplex 990.

lab@lab-445:~/Desktop/M_series_assembly/M4-M5$ free -m
             total       used       free     shared    buffers     cached
Mem:         32058      28989       3068          0       8424      18706
-/+ buffers/cache:       1859      30198
Swap:        30516          0      30516

Como pode ser mesmo quando não estou executando nada?

Aqui está a lista solicitada de aplicativos de 32 bits instalados:

lab@lab-445:~$ dpkg -l | grep i386  

ii  gcc-4.6-base:i386                               4.6.3-1ubuntu5                                      GCC, the GNU Compiler Collection (base package)
ii  libasn1-8-heimdal:i386                          1.6~git20120311.dfsg.1-2ubuntu0.1                   Heimdal Kerberos - ASN.1 library
ii  libasound2:i386                                 1.0.25-1ubuntu10.2                                  shared library for ALSA applications
ii  libavahi-client3:i386                           0.6.30-5ubuntu2.1                                   Avahi client library
ii  libavahi-common-data:i386                       0.6.30-5ubuntu2.1                                   Avahi common data files
ii  libavahi-common3:i386                           0.6.30-5ubuntu2.1                                   Avahi common library
ii  libc6:i386                                      2.15-0ubuntu10.7                                    Embedded GNU C Library: Shared libraries
ii  libc6-i386                                      2.15-0ubuntu10.7                                    Embedded GNU C Library: 32-bit shared libraries for AMD64
ii  libcapi20-3:i386                                1:3.12.20071127-0ubuntu11                           libraries for CAPI support
ii  libcomerr2:i386                                 1.42-1ubuntu2                                       common error description library
ii  libcroco3:i386                                  0.6.5-1ubuntu0.1                                    Cascading Style Sheet (CSS) parsing and manipulation toolkit
ii  libcups2:i386                                   1.5.3-0ubuntu8.5                                    Common UNIX Printing System(tm) - Core library
ii  libdb5.1:i386                                   5.1.25-11build1                                     Berkeley v5.1 Database Libraries [runtime]
ii  libdbus-1-3:i386                                1.4.18-1ubuntu1.7                                   simple interprocess messaging system (library)
ii  libdrm-intel1:i386                              2.4.52-1~precise1                                   Userspace interface to intel-specific kernel DRM services -- runtime
ii  libdrm-nouveau1a:i386                           2.4.52-1~precise1                                   Userspace interface to nouveau-specific kernel DRM services -- runtime
ii  libdrm-radeon1:i386                             2.4.52-1~precise1                                   Userspace interface to radeon-specific kernel DRM services -- runtime
ii  libdrm2:i386                                    2.4.52-1~precise1                                   Userspace interface to kernel DRM services -- runtime
ii  libexif12:i386                                  0.6.20-2ubuntu0.1                                   library to parse EXIF files
ii  libexpat1:i386                                  2.0.1-7.2ubuntu1.1                                  XML parsing C library - runtime library
ii  libffi6:i386                                    3.0.11~rc1-5                                        Foreign Function Interface library runtime
ii  libfontconfig1:i386                             2.8.0-3ubuntu9.1                                    generic font configuration library - runtime
ii  libfreetype6:i386                               2.4.8-1ubuntu2.1                                    FreeType 2 font engine, shared library files
ii  libgcc1:i386                                    1:4.6.3-1ubuntu5                                    GCC support library
ii  libgcrypt11:i386                                1.5.0-3ubuntu0.3                                    LGPL Crypto library - runtime library
ii  libgd2-xpm:i386                                 2.0.36~rc1~dfsg-6ubuntu2                            GD Graphics Library version 2
ii  libgettextpo0:i386                              0.18.1.1-5ubuntu3                                   GNU Internationalization library
ii  libgif4:i386                                    4.1.6-9ubuntu1                                      library for GIF images (library)
ii  libgl1-mesa-dri:i386                            8.0.4-0ubuntu0.7                                    free implementation of the OpenGL API -- DRI modules
ii  libgl1-mesa-glx:i386                            8.0.4-0ubuntu0.7                                    free implementation of the OpenGL API -- GLX runtime
ii  libglapi-mesa:i386                              8.0.4-0ubuntu0.7                                    free implementation of the GL API -- shared library
ii  libglib2.0-0:i386                               2.32.4-0ubuntu1                                     GLib library of C routines
ii  libglu1-mesa:i386                               8.0.4-0ubuntu0.7                                    Mesa OpenGL utility library (GLU)
ii  libgnutls26:i386                                2.12.14-5ubuntu3.8                                  GNU TLS library - runtime library
ii  libgomp1:i386                                   4.6.3-1ubuntu5                                      GCC OpenMP (GOMP) support library
ii  libgpg-error0:i386                              1.10-2ubuntu1                                       library for common error values and messages in GnuPG components
ii  libgphoto2-2:i386                               2.4.13-1ubuntu1.2                                   gphoto2 digital camera library
ii  libgphoto2-port0:i386                           2.4.13-1ubuntu1.2                                   gphoto2 digital camera port library
ii  libgpm2:i386                                    1.20.4-4                                            General Purpose Mouse - shared library
ii  libgssapi-krb5-2:i386                           1.10+dfsg~beta1-2ubuntu0.5                          MIT Kerberos runtime libraries - krb5 GSS-API Mechanism
ii  libgssapi3-heimdal:i386                         1.6~git20120311.dfsg.1-2ubuntu0.1                   Heimdal Kerberos - GSSAPI support library
ii  libgstreamer-plugins-base0.10-0:i386            0.10.36-1ubuntu0.1                                  GStreamer libraries from the "base" set
ii  libgstreamer0.10-0:i386                         0.10.36-1ubuntu1                                    Core GStreamer libraries and elements
ii  libhcrypto4-heimdal:i386                        1.6~git20120311.dfsg.1-2ubuntu0.1                   Heimdal Kerberos - crypto library
ii  libheimbase1-heimdal:i386                       1.6~git20120311.dfsg.1-2ubuntu0.1                   Heimdal Kerberos - Base library
ii  libheimntlm0-heimdal:i386                       1.6~git20120311.dfsg.1-2ubuntu0.1                   Heimdal Kerberos - NTLM support library
ii  libhx509-5-heimdal:i386                         1.6~git20120311.dfsg.1-2ubuntu0.1                   Heimdal Kerberos - X509 support library
ii  libice6:i386                                    2:1.0.7-2build1                                     X11 Inter-Client Exchange library
ii  libieee1284-3:i386                              0.2.11-10build1                                     cross-platform library for parallel port access
ii  libjpeg-turbo8:i386                             1.1.90+svn733-0ubuntu4.4                            IJG JPEG compliant runtime library.
ii  libjpeg8:i386                                   8c-2ubuntu7                                         Independent JPEG Group's JPEG runtime library (dependency package)
ii  libk5crypto3:i386                               1.10+dfsg~beta1-2ubuntu0.5                          MIT Kerberos runtime libraries - Crypto Library
ii  libkeyutils1:i386                               1.5.2-2                                             Linux Key Management Utilities (library)
ii  libkrb5-26-heimdal:i386                         1.6~git20120311.dfsg.1-2ubuntu0.1                   Heimdal Kerberos - libraries
ii  libkrb5-3:i386                                  1.10+dfsg~beta1-2ubuntu0.5                          MIT Kerberos runtime libraries
ii  libkrb5support0:i386                            1.10+dfsg~beta1-2ubuntu0.5                          MIT Kerberos runtime libraries - Support library
ii  liblcms1:i386                                   1.19.dfsg-1ubuntu3                                  Little CMS color management library
ii  libldap-2.4-2:i386                              2.4.28-1.1ubuntu4.4                                 OpenLDAP libraries
ii  libllvm3.0:i386                                 3.0-4ubuntu1                                        Low-Level Virtual Machine (LLVM), runtime library
ii  libltdl7:i386                                   2.4.2-1ubuntu1                                      A system independent dlopen wrapper for GNU libtool
ii  libmpg123-0:i386                                1.12.1-3.2ubuntu1                                   MPEG layer 1/2/3 audio decoder -- runtime library
ii  libncurses5:i386                                5.9-4                                               shared libraries for terminal handling
ii  libopenal1:i386                                 1:1.13-4ubuntu3                                     Software implementation of the OpenAL API (shared library)
ii  liborc-0.4-0:i386                               1:0.4.16-1ubuntu2                                   Library of Optimized Inner Loops Runtime Compiler
ii  libp11-kit0:i386                                0.12-2ubuntu1                                       Library for loading and coordinating access to PKCS#11 modules - runtime
ii  libpciaccess0:i386                              0.12.902-1ubuntu0.2                                 Generic PCI access library for X
ii  libpcre3:i386                                   8.12-4                                              Perl 5 Compatible Regular Expression Library - runtime files
ii  libpng12-0:i386                                 1.2.46-3ubuntu4                                     PNG library - runtime
ii  libroken18-heimdal:i386                         1.6~git20120311.dfsg.1-2ubuntu0.1                   Heimdal Kerberos - roken support library
ii  libsane:i386                                    1.0.22-7ubuntu1                                     API library for scanners
ii  libsasl2-2:i386                                 2.1.25.dfsg1-3ubuntu0.1                             Cyrus SASL - authentication abstraction library
ii  libsasl2-modules:i386                           2.1.25.dfsg1-3ubuntu0.1                             Cyrus SASL - pluggable authentication modules
ii  libselinux1:i386                                2.1.0-4.1ubuntu1                                    SELinux runtime shared libraries
ii  libsm6:i386                                     2:1.2.0-2build1                                     X11 Session Management library
ii  libsqlite3-0:i386                               3.7.9-2ubuntu1.1                                    SQLite 3 shared library
ii  libssl1.0.0:i386                                1.0.1-4ubuntu5.20                                   SSL shared libraries
ii  libstdc++6:i386                                 4.6.3-1ubuntu5                                      GNU Standard C++ Library v3
ii  libtasn1-3:i386                                 2.10-1ubuntu1.2                                     Manage ASN.1 structures (runtime)
ii  libtiff4:i386                                   3.9.5-2ubuntu1.6                                    Tag Image File Format (TIFF) library
ii  libtinfo5:i386                                  5.9-4                                               shared low-level terminfo library for terminal handling
ii  libunistring0:i386                              0.9.3-5                                             Unicode string library for C
ii  libusb-0.1-4:i386                               2:0.1.12-20                                         userspace USB programming library
ii  libuuid1:i386                                   2.20.1-1ubuntu3.1                                   Universally Unique ID library
ii  libv4l-0:i386                                   0.8.6-1ubuntu2                                      Collection of video4linux support libraries
ii  libv4lconvert0:i386                             0.8.6-1ubuntu2                                      Video4linux frame format conversion library
ii  libwind0-heimdal:i386                           1.6~git20120311.dfsg.1-2ubuntu0.1                   Heimdal Kerberos - stringprep implementation
ii  libx11-6:i386                                   2:1.4.99.1-0ubuntu2.2                               X11 client-side library
ii  libx11-xcb1:i386                                2:1.4.99.1-0ubuntu2.2                               Xlib/XCB interface library
ii  libxau6:i386                                    1:1.0.6-4                                           X11 authorisation library
ii  libxcb-glx0:i386                                1.8.1-1ubuntu0.2                                    X C Binding, glx extension
ii  libxcb1:i386                                    1.8.1-1ubuntu0.2                                    X C Binding
ii  libxcomposite1:i386                             1:0.4.3-2build1                                     X11 Composite extension library
ii  libxcursor1:i386                                1:1.1.12-1ubuntu0.1                                 X cursor management library
ii  libxdamage1:i386                                1:1.1.3-2build1                                     X11 damaged region extension library
ii  libxdmcp6:i386                                  1:1.1.0-4                                           X11 Display Manager Control Protocol library
ii  libxext6:i386                                   2:1.3.0-3ubuntu0.1                                  X11 miscellaneous extension library
ii  libxfixes3:i386                                 1:5.0-4ubuntu4.2                                    X11 miscellaneous 'fixes' extension library
ii  libxi6:i386                                     2:1.7.1.901-1ubuntu1~precise1                       X11 Input extension library
ii  libxinerama1:i386                               2:1.1.1-3ubuntu0.1                                  X11 Xinerama extension library
ii  libxml2:i386                                    2.7.8.dfsg-5.1ubuntu4.11                            GNOME XML library
ii  libxpm4:i386                                    1:3.5.9-4                                           X11 pixmap library
ii  libxrandr2:i386                                 2:1.3.2-2ubuntu0.2                                  X11 RandR extension library
ii  libxrender1:i386                                1:0.9.6-2ubuntu0.1                                  X Rendering Extension client library
ii  libxslt1.1:i386                                 1.1.26-8ubuntu1.3                                   XSLT 1.0 processing library - runtime library
ii  libxt6:i386                                     1:1.1.1-2ubuntu0.1                                  X11 toolkit intrinsics library
ii  libxxf86vm1:i386                                1:1.1.1-2ubuntu0.1                                  X11 XFree86 video mode extension library
ii  syslinux-legacy                                 2:3.63+dfsg-2ubuntu5                                Bootloader for Linux/i386 using MS-DOS floppies
ii  wine-gecko1.4:i386                              1.4.0-0ubuntu2                                      Microsoft Windows compatibility layer (embedded web browser)
ii  wine1.4-i386:i386                               1.4-0ubuntu4.1                                      Microsoft Windows Compatibility Layer (32-bit support)
ii  zlib1g:i386                                     1:1.2.3.4.dfsg-3ubuntu4                             compression library - runtime

e as informações da máquina:

lab@lab-445:~$ uname -a
Linux lab-445 3.2.0-65-generic #99-Ubuntu SMP Fri Jul 4 21:03:29 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux  

    

Answer 1

Sua RAM é totalmente reconhecida, já que diz 32058 MB total.

Eu acho que você acha que a sua memória é totalmente usada, embora nada esteja rodando? Isso não é verdade, porque você tem 30198 MB de memória disponível para seus aplicativos.

O resto que não aparece como "memória livre" ( 3068 MB) é usado como cache. Esta é uma ótima tecnologia que torna o acesso ao HDD muito mais rápido ao armazenar em cache os dados que o Ubuntu acha que você pode precisar em breve do disco para a RAM livre. Esse cache não é mostrado como "livre", mas está disponível porque o kernel pode descartar o cache imediatamente quando a RAM é necessária para seus aplicativos.

Consulte o link para obter informações mais bem visualizadas e de fácil compreensão.