Redhat 7.2 upgrade to Redhat 9.1 without booting from a disk

From Nick Pringle

Answered By Thomas Adam, Faber Fedor, Dan Wilder, Heather Stern, Ben Okopnik

Hi

I rent a Redhat 7.2 system installed on a host machine 'in a galaxy far, far away'. I want to upgrade to Redhat 9.1 but cannot follow the prescribe route because I cannot boot from floppy or cd the way Redhat say to do the upgrade. I can, however, always boot from an emergency ram disk and then mount the real system to work on it. When booted via this emergency RAM disk I have full net access and have ftp access to all the Redhat CDs etc. Is there any way of running the upgrade procedure 'manually'?

Regards Nick Pringle

[Thomas] How do you mean by installing it "manually"? The RH installer allows you the choice of doing either http/ftp/cdrom install, depending on what you choose.

Are you trying to say then, that you want to only upgrade certain packages on your system (N.B. This is not a good idea, since as this is a higher version than the version currently on your system, trying to upgrade certain packages leads to "dependency hell"). Cf:

http://linuxgazette.net/issue71/tag/3.html

Could you try and provide more details. Thanks.

[Faber] That's the problem he has, Thomas. The box is "far far away" and he can't just "put in the CD, boot the machine, and choose http/ftp/cdrom" after selecting his language mouse and keyboard. He isn't at the machine.

So he ants to know if he can manually start the installation process, i.e. not reboot the machine.

It's a good question and I haven't found a solution yet.

[Dan] Maybe he shoulda used Debian.

I routinely upgrade Debian systems one major release level via an ssh login. So far not "far far away", but without touching the box being upgraded, yes. At one point I upgraded a running web server this way, with only a fifteen minute interruption to its services.

Which proves such a thing can be done. Now whether other distributions allow for it ...

[Heather] I am a lot more careful about letting debian do its automagical thing if I know I can't get over to that machine and whack it one. There have been a few times in my life, when playing with Debian's idea of the leading edge, I took too careless a leap and added that "b" noise to the word. Ouchie.

Essentially, I use a curses-mode selector such as aptitude. I update, and I pick some very basic stuff to make sure the raw parts are definitely grabbed first. This generally means dpkg, debconf and its related parts - libc and things having to do with login, such as the shell, pam, and so on. All in all I've usually done 4 or 5 small sets of critical utilities (not always members of "base" - sometimes in admin, or related to the actual purpose of the system). Before anything whose improper behavior would give me the willies, I use dpkg-repack to save an instance of its current bits before I allow it to upgrade. Yeah, I bail out of the selector a lot. But when I finally am happy with how perl settled in, I won't need to worry about the rest of it.

[Ben] 1) Install the system on a local machine; configure and tweak.

2) Copy everything across (FTP or whatever) to a new partition on the remote machine.

3) Carefully adjust the remote "lilo.conf" to boot the new "installation" on the next reboot.

Anybody see a problem with this scenario? Sure, some stuff is going to require tweaking afterwards - but that's true of any new install.

[Dan] Sure sounds a lot like the safest upgrade procedure for what's still, for quirky reasons, my favorite distribution ... Slackware.

It'd be nice if the ever-so-much featureful RH could do better.

---

Hi. Thanks for the prompt reply.

[Thomas] All part of the service, sir!

I recently upgraded the machine in my office from Redhat Linux 7.2 to Redhat 9.1. No trouble. I just booted from the CD, click the options in graphics mode and did the upgrade. So I've been through the process on a PC I can touch.

[Thomas] Yep, installers are becoming easier and easier. I am sure people like Jim Dennis and Ben Okopnik (resident on this list) will remember the days of black and white, and having to use the "friendly" program fdisk

But I am trying out a hosting package provided by a company called Oneandone. It's a very attractive solution because they have fast access, I won't have to use a machine and UPS of my own and they are cheap! It's $50 a month. It's on www.oneandone.co.uk as a Root Server 1. I live in Britain,

[Thomas] Well, well, well. I live in England too Small world, eh? I have heard of oneandone, but never really looked any further, until now

I think the machine might be in Germany but I'm not actually sure. I don't know what sort or hardware they run but I am simply unable to detect if it is virtual in any way. Even the hardware reporting at boot time says it is a real machine. I imagine they have racks of tiny machines with only processor, memory, Realtek netcard and a hard disk.

[Thomas] A reasonable assumption.

I get Redhat Linux 7.2 installed but very limited support! When I point out to them that Redhat 7.2 becomes obsolete in November they agree it will but cannot upgrade my Server package. To use the service I really need to know I can upgrade at some time.

Hmm, I am going to be picky here and say that NO Linux distibution becomes obsolete. Yes, some of the programs will be at a lower version number than some more recent ones, but as long as it works and does what you want it to do -- there is no reason to upgrade at all. That is perhaps the selling point of Linux for me over Microsoft --- you don't, nor are you forced to upgrade. If it works, keep it. Heck, I know some people who are still running kernel 1.x.x

[Heather] I'll have to agree; I've safely let systems lay with only the important service ever being updated, behind a nice little firewall whose kernel is updated more often.

I am truly remote. I ONLY have SSH access. I cannot boot from anything other than the hard disk of the remote machine. When I upgraded my local machine in the office I booted with the Redhat CD1 on my local CD drive. As far as I can see Redhat upgrade requires you to BOOT from either a floppy or CD. If I could boot from the CD I know I could choose ftp/cd/or local hard disk but I cannot do the very first step.

[Thomas] I see your problem If you have SSH support, then what I would be inclined to do is try and run a program called "up2date", like so:

up2date -u

essentially this locates a RH server and updates old packages that you have on your current remote system with newer ones. It does not though perform a dist-upgrade. I suppose that you could look at "up2date" as a very childlike form of Debian's "apt-get".

So, this is a half-way solution to your problem.

Another, perhaps more direct approach is to use the utility "wget" download the ".iso" files, and mount them on a loopback, such that you can then issue:

rpm -ivh *.rpm

Sorry to drag it on a bit but I hope the above clarifies the situation.

If you haven't lost the will to live by now thank you very much for listening.

Incidentally I agree that partial upgrades and going through each of the RPMs one at a time will result in "dependency hell" which is why I need a 3rd route.

[Heather] There you have it folks; if anyone has had their own successes in such distant climes, maybe you'd like to write us an article someday soon?