6 ms·

16 Linux server monitoring commands you really need to know

33 points by CrankyBear 10y ago

n00b101 10y ago
htop may be better than top
- mi100hael 10y ago
  I find when a server is close to using max CPU or mem, htop requires a surprising amount of resources that result in it lagging quite a bit.
  - jdalgetty 10y ago
    I prefer htop.
    - senorsmile 10y ago
      I know install glances and use it in place of htop on all servers. Much more info and more customizable than htop.
dsr_ 10y ago
Starts by assuming that runlevels mean the same thing on all Linux variants.
- whalesalad 10y ago
  Yeah... a buzzfeed style inbound marketing post asking me to modify my runlevel. What could go wrong?
  - mmjaa 10y ago
    Welcome to the modern world, where knowing what a run level IS, let alone know how to USE one, matters. What could go wrong? You forget to try to understand the question: what is my run level?
  - gist 10y ago
    Exactly what an ephemeral DO vps is good for!
- gnur 10y ago
  Worse still, it starts by assuming runlevels still have a meaning. Nearly all modern distro's are now running systemd, which has no notion of runlevels (targets are kind of the same but also very different!)
  - rhblake 10y ago
    For reference, https://wiki.archlinux.org/index.php/Systemd#Targets https://wiki.archlinux.org/index.php/Systemd#Targets is a nice little summary of how it's usually done these days.
  - CrankyBear 10y ago
    The newest distros use systemd, but IT departments seldom run the newest distros on servers. For example, AWS's Linux AWI still doesn't have systemd support.
    - JdeBP 10y ago
      In several cases, the versions that preceded them ran upstart. Advice that has a blanket assumption of the presence of van Smoorenburg init has been wrong for longer than systemd has been around.
dimitar 10y ago
netstat is deprecated on Linux, ss should be used instead. Learning the differences is a good exercise by itself
MisterKent 10y ago
This is a terrible article which doesn't even meet the requirements for posting to hackernews.
Mister_Snuggles 10y ago
It seems that a lot of distributions have moved to systemd - do runlevels and inittab even have any meaning for a systemd-based distribution?
- Zancarius 10y ago
  Not really. systemd uses targets (see the link to the Arch wiki from rhblake, above [1]) instead which are arguably more flexible. Although systemd understands runlevels with the runlevel.target, most services will tend to use multi-user.target or graphical.target. Although you can also create custom targets for various purposes. I suspect* the runlevel targets are probably used by and intended for systemd's initscript/sysvinit compatibility layer to ease porting. I use Arch, so I can't comment specifically on this matter since most sysvinit compatibility cruft (outside init/halt/reboot/poweroff) has long been removed. [1] https://news.ycombinator.com/item?id=13785448 https://news.ycombinator.com/item?id=13785448
- JdeBP 10y ago
  They have a meaning, but the systemd people describe them as "obsolete". * http://jdebp.eu./FGA/inittab-is-history.html http://jdebp.eu./FGA/inittab-is-history.html * http://unix.stackexchange.com/a/204075/5132 http://unix.stackexchange.com/a/204075/5132 * http://unix.stackexchange.com/a/196014/5132 http://unix.stackexchange.com/a/196014/5132

33 points by CrankyBear 10y ago

n00b101 10y ago

htop may be better than top

mi100hael 10y ago
I find when a server is close to using max CPU or mem, htop requires a surprising amount of resources that result in it lagging quite a bit.
- jdalgetty 10y ago
  I prefer htop.
  - senorsmile 10y ago
    I know install glances and use it in place of htop on all servers. Much more info and more customizable than htop.

dsr_ 10y ago

Starts by assuming that runlevels mean the same thing on all Linux variants.

whalesalad 10y ago
Yeah... a buzzfeed style inbound marketing post asking me to modify my runlevel. What could go wrong?
- mmjaa 10y ago
  Welcome to the modern world, where knowing what a run level IS, let alone know how to USE one, matters. What could go wrong? You forget to try to understand the question: what is my run level?
- gist 10y ago
  Exactly what an ephemeral DO vps is good for!
gnur 10y ago
Worse still, it starts by assuming runlevels still have a meaning. Nearly all modern distro's are now running systemd, which has no notion of runlevels (targets are kind of the same but also very different!)
- rhblake 10y ago
  For reference, https://wiki.archlinux.org/index.php/Systemd#Targets https://wiki.archlinux.org/index.php/Systemd#Targets is a nice little summary of how it's usually done these days.
- CrankyBear 10y ago
  The newest distros use systemd, but IT departments seldom run the newest distros on servers. For example, AWS's Linux AWI still doesn't have systemd support.
  - JdeBP 10y ago
    In several cases, the versions that preceded them ran upstart. Advice that has a blanket assumption of the presence of van Smoorenburg init has been wrong for longer than systemd has been around.

dimitar 10y ago

netstat is deprecated on Linux, ss should be used instead. Learning the differences is a good exercise by itself

MisterKent 10y ago

This is a terrible article which doesn't even meet the requirements for posting to hackernews.

Mister_Snuggles 10y ago

It seems that a lot of distributions have moved to systemd - do runlevels and inittab even have any meaning for a systemd-based distribution?

Zancarius 10y ago
Not really. systemd uses targets (see the link to the Arch wiki from rhblake, above [1]) instead which are arguably more flexible. Although systemd understands runlevels with the runlevel.target, most services will tend to use multi-user.target or graphical.target. Although you can also create custom targets for various purposes. I suspect* the runlevel targets are probably used by and intended for systemd's initscript/sysvinit compatibility layer to ease porting. I use Arch, so I can't comment specifically on this matter since most sysvinit compatibility cruft (outside init/halt/reboot/poweroff) has long been removed. [1] https://news.ycombinator.com/item?id=13785448 https://news.ycombinator.com/item?id=13785448
JdeBP 10y ago
They have a meaning, but the systemd people describe them as "obsolete". * http://jdebp.eu./FGA/inittab-is-history.html http://jdebp.eu./FGA/inittab-is-history.html * http://unix.stackexchange.com/a/204075/5132 http://unix.stackexchange.com/a/204075/5132 * http://unix.stackexchange.com/a/196014/5132 http://unix.stackexchange.com/a/196014/5132