Underutilization of Linux memory Post: 303044181

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Operating Systems Linux Underutilization of Linux memory Post 303044181 by Neo on Sunday 16th of February 2020 07:42:42 AM

02-16-2020

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And tomorrow, I will take this dedicated Ubuntu server, currently looks like this (runs MQTT, mysql, apache2 and a number of web sites, does backups, etc):

Code:

top - 06:40:25 up 35 days, 6 min,  1 user,  load average: 0.05, 0.12, 0.16
Tasks: 224 total,   1 running, 223 sleeping,   0 stopped,   0 zombie
%Cpu(s):  1.5 us,  0.9 sy,  0.0 ni, 97.5 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
KiB Mem : 32652952 total, 16986476 free,   694036 used, 14972440 buff/cache
KiB Swap:  7996412 total,  7996412 free,        0 used. 31071156 avail Mem 

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND                                                                                                           
  950 mysql     20   0 2749912 333616  19552 S   0.7  1.0 542:11.32 mysqld                                                                                                            
 8346 www-data  20   0  479644  32704  21104 S   0.7  0.1   0:00.02 apache2                                                                                                           
 8353 www-data  20   0  477684  24696  13064 S   0.7  0.1   0:00.02 apache2                                                                                                           
  901 www-data  20   0  343920  25120   2356 S   0.3  0.1  73:38.94 memcached                                                                                                         
 7461 www-data  20   0  477100  15708   4556 S   0.3  0.0   0:00.05 apache2                                                                                                           
 7607 www-data  20   0  477100  15708   4556 S   0.3  0.0   0:00.03 apache2                                                                                                           
 8205 www-data  20   0  477100  15708   4556 S   0.3  0.0   0:00.01 apache2                                                                                                           
    1 root      20   0  185144   5792   4040 S   0.0  0.0   2:55.18 systemd       
..
...
...
...

Will do the same... will turn off swap complete for a day and compare before and after.

In this manner, everyone can see two very different real-world, live Linux server examples of running with swap on and off; in both cases, there is plenty of memory. In fact, the server in this post (the dedicated server) shows zero swap being used even though the uptime is:

Code:

ubuntu# uptime
 06:44:46 up 35 days, 11 min,  1 user,  load average: 0.31, 0.22, 0.19

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LEARN ABOUT LINUX

a2dissite

A2ENSITE(8)                                                   System Manager's Manual                                                  A2ENSITE(8)

NAME

       a2ensite, a2dissite - enable or disable an apache2 site / virtual host

SYNOPSIS

       a2ensite [ [-q|--quiet] site]

       a2dissite [ [-q|--quiet] site]

DESCRIPTION

       This manual page documents briefly the a2ensite and a2dissite commands.

       a2ensite is a script that enables the specified site (which contains a <VirtualHost> block) within the apache2 configuration.  It does this
       by creating symlinks within /etc/apache2/sites-enabled.  Likewise, a2dissite disables a site by removing those  symlinks.   It  is  not  an
       error to enable a site which is already enabled, or to disable one which is already disabled.

       Apache  treats  the very first virtual host enabled specially as every request not matching any actual directive is being redirected there.
       Thus it should be called 000-default in order to sort before the remaining hosts to be loaded first.

OPTIONS

       -q, --quiet
              Don't show informative messages.

       -m, --maintmode
              Enables the maintainer mode, that is the program invocation is effectuated automatically by a maintainer script. This switch  should
              not be used by end users.

       -p, --purge
              When disabling a module, purge all traces of the module in the internal state data base.

EXIT STATUS

       a2ensite and a2dissite exit with status 0 if all sites are processed successfully, 1 if errors occur, 2 if an invalid option was used.

EXAMPLES

              a2dissite 000-default

       Disables the default site.

FILES

       /etc/apache2/sites-available
              Directory with files giving information on available sites.

       /etc/apache2/sites-enabled
              Directory with links to the files in sites-available for enabled sites.

SEE ALSO

       apache2ctl(8).

AUTHOR

       This  manual  page  was written by Stefan Fritsch <sf@debian.org> (based on the a2enmod manual page by Daniel Stone <daniel@sfarc.net>) for
       the Debian GNU/Linux distribution.

                                                                    8 June 2007                                                        A2ENSITE(8)

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