[OpenIndiana-discuss] OI rpool on USB flash in N40L?

[Jim Klimov]

On 2013-01-27 16:58, andy thomas wrote:
>      5. next, to preserve the state of /var and /tmp across reboots
>         add this to your /etc/rc.shutdown.local script (you might need
>         to create this if it doesn't exist):
>
>          # Insert other shutdown procedures here
>
>          tar czf /md_backups/var.tgz /var
>          tar czf /md_backups/tmp.tgz /tmp
>
>          echo '.'
>          exit 0


I'd be more comfortable with a transactional approach - create the new
archive in a tempfile on the USB root disk, after successful completion
rename it over the old file and/or roll its name syslog-style to keep
the previous archive too. This way a sudden poweroff or a write error
won't leave you with no usable archive at all. For example:

rm -f /md_backups/*.__WRITING__
for F in var tmp; do
     tar czf /md_backups/$F.tgz.__WRITING__ /$F && \
     rm -f /md_backups/$F.tgz.prev && \
     ( [ -s /md_backups/$F.tgz ] && \
       ln /md_backups/$F.tgz /md_backups/$F.tgz.prev || true ) && \
     mv -f /md_backups/$F.tgz.__WRITING__ /md_backups/$F.tgz
done


This is off the top of my head, may need fixes to actually work right ;)
In particular, do verify that such "rm -f" succeeds regardless of the
file's existance, and that "mv -f" unlinks the older file before
renaming another over this name - i.e. inodes change (ls -lani).

HTH,
//Jim