I have done upgrading from slack 9.0 to 9.1 on-site.

However, I wonder is it possible to perform the upgrade remotely?
I have already downloaded the source of slack v9.1 onto the slack9.0
ie. Can I upgrade from remote via
- upgradepkg /root/slackware/a/glibc-solibs-*.tgz
- upgradepkg /root/slackware/a/pkgtools-*.tgz
- installpkg /root/slackware/a/sed-*.tgz
- upgradepkg *.tgz (on all directory, a, ap, n , l, d, etc)
- lilo -v (rerun lilo when complete)

The only differences I see is that I did not bring the server to single user mode. Is it necessary to bring down to single user mode?

Thanks in advance.

What have to bring down to single user mode when upgrading those packages? No wonder I screwed up my Slack 9.0 when I use swaret to upgrade glibc.

But I have upgraded glibc on Slackware 9.1 to current (twice) without bringing it down to single user mode. And it still works without any problem.