Re: Question about /home

[Todd Gruhn <tgruhn2%gmail.com@localhost>]

WOW. Thanks.

I recall having to set up /usr/guest/todd in NetBSD v0.9b to NetBSD .2.x
I will try that again...

On Sat, Jan 22, 2022 at 2:52 PM Michael Parson <mparson%bl.org@localhost> wrote:
>
> On 2022-01-22 11:20, Todd Gruhn wrote:
> > is /home in the  /  directory?   What happens if  /  is too small?
>
> /home can be it's own partition, it's own disk, or, it can be on the /
> fs, all depend on how you set it up.
>
> If a filesystem fills up, then, the first obvious problem is that
> nothing
> new can be written.  Depending on which directories are on the
> filesystem,
> the consequences vary.
>
> If you have a single filesystem, /, and you fill it up, then you're
> not going to get any more logs (/var/log/*), mail won't be delivered
> (/var/mail, /var/spool/mqueue), anything that creates tmp files in /tmp
> or /var/tmp to function are going to have problems, etc, users logged in
> won't be able to do much other than log in and look at things, won't be
> able to edit files, download anything, compile programs, etc.
>
> > Can it be moved to /usr?
>
> It can be, as long as you either symlink /usr/home to /home, or fix
> everything that looks for home dirs to know to look in /usr/home.
> This will mostly be fixing entries in /etc/passwd, but there could be
> scripts, config files, etc, that expect a given user's $HOME to be under
> /home
>
> > I recall that /home had its own filesystem/sector once upon a time...
>
> Back in the old days, when disks were measured in megabytes, possibly
> small numbers of gigabytes, and before we had things like log structured
> filesystems, it was good practice to separate stuff that might have
> lots of read/writes off the / filesystem so that should something
> catastrophic happen (power loss, kernel panic, etc), the potential
> corruption to / would be limited and it would most likely pass the
> boot-up fsck and you'd have a functional enough system to repair any
> other damage that might have been done. So you might have /usr, /var,
> and /home on separate partitions or even disks. If you were in a
> networked environment, /home might even be an NFS mount from somewhere
> else, might even have /usr/local be an NFS mount that has common tools
> or programs that might be shared across multiple systems.
>
> In those days, I tended to set up my systems to look something like:
>
> /
> /var
> /home
> /usr
> /tmp (tended to be a ramdisk of some sort)
>
> Then, depending on the number of disks I had, if it was a networked
> environment with shared resources, etc, I might have separate /usr/local
> partition, disk, or network mount, /home might be shared from a central
> server, etc.
>
> The other advantage to separate partitions back then was that the unix
> tape-backup program dump(8) used to only be able to handle things on the
> partition level, so, in order to back up /home separate from the other
> stuff, you needed /home to be on a partition of its own. At some point,
> at least on NetBSD, dump(8) was adapted to handle things at a directory
> level, removing that limitation.
>
> --
> Michael Parson
> Pflugerville, TX
> KF5LGQ
>