[CentOS] mount points @install time

Tue Oct 9 17:06:59 UTC 2018
Warren Young <warren at etr-usa.com>

On Oct 9, 2018, at 6:42 AM, lejeczek via CentOS <centos at centos.org> wrote:
> 
> is there a way to add custom mount points at installation point?

Yes: tell the installer that you want to do manual partitioning.  Then you can create whatever partitioning scheme you like.

> And if there is would you say /usr should/could go onto a separate partition?

Once upon a time, yes, but not any more:

   https://unix.stackexchange.com/a/4194/138

A complete CentOS installation is in the single-digit gigs, which is smaller than even most removable media these days.  Even small embedded systems can get a useful Linux installation onto a single flash IC or whatever it is they use for mass storage.

When installing to a single volume, the only partitions I make these days are to provide storage space isolation, as a cheap alternative to setting up quotas, log rotation, etc.:

*  /var if you expect large log files, large MySQL DBs, large /var/www trees, etc.

*  /home if you want to prevent problems with the root disk if normal users end up filling that partition with files they create.

*  Network file shares for the same reason.

With filesystems featuring pooled/shared storage (ZFS, btrfs, APFS…) I tend to create only one partition, then rely on the filesystem’s quota feature if necessary to avoid such problems.

Even on single-volume systems without pooled storage, you can usually get away with a minimal partition scheme:

*  Small /boot (plus maybe /boot/efi and/or /biosboot)

*  swap partition

*  root for everything else

This is because modern Unix-type filesystems will will typically reserve the last 5% of the space for root only, so that normal users simply cannot fill a filesystem, so that the OS won’t crash due to system daemons being unable to write to the disk.