[GTALUG] Boot setup issues

[D. Hugh Redelmeier]

| From: o1bigtenor via talk <talk at gtalug.org>

Note: I am only an amateur sysadmin.

| One of my linux mentors, who calls himself a linux dinosaur (started on
| a System V on a pc)

Picky picky: System V isn't Linux.  It's UNIX.

I first used UNIX seriously with 4th or 5th Edition in 1975.  But I
first became strongly interested in 1974 from reading "The UNIX
Time-Sharing System" in the Communications of the ACM.

I think that a number of GTALUG folks used Linux before I did.  I
switched my desktop from Solaris on SPARC to Linux about 1997 (I
played with Linux before that).

| even advocates for a separate partition for /var/log
| to forestall any software issues choking off disk usage.

Good point.  What causes disk-full events for you?  If you can isolate
them to separate filesystems, that's good.

Here are the ones that have hit me:

- too many log messages (/var/log).  That can easily be cured by
  log system settings.

- too much email (/var/spool)

- too many saved update packages (due to a PackageKit / dnf bug)
  (/var/cache)

- too many packages installed (/)

- too many core dumps (/var/spool/abrt)
  A firefox dump usually takes 4GiB or so on my system.

HDDs are so big and cheap these days that the simplest solution is to
wildly over-allocate for each partition.

Unfortunately, SSDs are so much faster that you ought to use them and
their capacity costs more.  I use both.  I haven't bothered to put any
problematic directories on the HDD.

|  One of my frustrations with linux has
| been that it can be very difficult to find clear understandable information
| on many parts of the system. Much of the documentation seems to be
| written for someone who is well versed in things and is looking for a clue
| or a reminder on 'how things work'.

There are other challenges

- Linux is very large.  Mostly things get added and very little gets 
  deleted.
  (When I first used UNIX, the largest RAM was 256KiB.  It ran 
  off a disk that was 2.5MB.  You can bet is was simpler.)

- Documentation gets out of date.

- Linux is very general-purpose.  How you should set it up depends on
  many things.  Consider the difference between Linux embedded in a
  home router and Linux running a supercomputer.  (Most routers,
  smartphones, tablets, supercomputers, websites, cloud systems, etc.
  run Linux.)

- each distro is a different.  Each installation can be different.

One key to understanding Linux is to understand its anatomy.  Then you
can study the organs of interest in isolation.