[SOLVED] How to trick centos yum into looking like a later release?

fred2014 · 03-03-2018, 06:49 AM

I'm looking into using yumdownloader to download rpm's

I have a centos 6 system but I want to download the
rpms and deps for a centos 7 system

I cannot replace the C6 with C7 on my browsing machine.
I could back it up or possibly even dual boot into a C7
installation - or maybe install C7 on a thumb drive but all
those are a bit cumbersome.

The simplest answer is probably the "live" thumbdrive install
of C7 but that then ties up a thumbdrive - currently
I think it is the best option though.

I was wondering if there was an easy way to convince
yum (and hence yumdownloader) that my C6 was a C7
in a simple easily swapped back way.

For example is there a centos variable I can just change without
causing hidden issues? Or a .conf change maybe?
I'm looking at it this way because it may be a more general
solution for myself and possibly others.(avoiding future need
to use the thumbdrive as releases change)

Part of the complication I see is finding a simple way of
installing the correct repos for C7 and then quickly swapping
them back to C6 - A bash script would probably do that
but I'm not overly familiar with bash and the consequences of
this to the host C6 OS.

Any constructive comments or suggestions welcome
TIA
F.

michaelk · 03-03-2018, 08:14 AM

In reference to the OPs other thread.

https://www.linuxquestions.org/quest...go-4175624826/

Previous contents redacted.

rknichols · 03-03-2018, 09:16 AM

If all you want to do is download the RPMs and not install them, that should be no problem. Just use "--releasever", for example:

Code:

yumlownloader --releasever=7 bash

From my CentOS 6.9 system, that gets me bash-4.2.46-29.el7_4.x86_64.rpm .

TB0ne · 03-03-2018, 09:27 AM

Quote:

Originally Posted by fred2014

I'm looking into using yumdownloader to download rpm's
I have a centos 6 system but I want to download the rpms and deps for a centos 7 system

I cannot replace the C6 with C7 on my browsing machine. I could back it up or possibly even dual boot into a C7 installation - or maybe install C7 on a thumb drive but all those are a bit cumbersome.

The simplest answer is probably the "live" thumbdrive install of C7 but that then ties up a thumbdrive - currently I think it is the best option though. I was wondering if there was an easy way to convince yum (and hence yumdownloader) that my C6 was a C7 in a simple easily swapped back way.

For example is there a centos variable I can just change without causing hidden issues? Or a .conf change maybe? I'm looking at it this way because it may be a more general solution for myself and possibly others.(avoiding future need to use the thumbdrive as releases change)

Part of the complication I see is finding a simple way of installing the correct repos for C7 and then quickly swapping them back to C6 - A bash script would probably do that but I'm not overly familiar with bash and the consequences of this to the host C6 OS.

What you're wanting to do is a very bad idea. Mixing repos for different versions will (as michaelk rightly said), break your system. If you'd like to use CentOS 7, the *BEST* option is to back up your data, and do a fresh install.

While an in-place upgrade is an option, I would never do one unless I had to. I've had bad luck/gremlins when doing such things, as you CAN be left with 'residuals' from the previous version lying about. Strange things can happen, and a clean install is just better, in my opinion. If you just want to downlaod the RPM's, you can use wget to grab them...but as soon as you start installing/using them on C6, be prepared to do that fresh install whether you want to or not.

rknichols · 03-03-2018, 09:30 AM

Quote:

Originally Posted by TB0ne

What you're wanting to do is a very bad idea. Mixing repos for different versions will (as michaelk rightly said), break your system. If you'd like to use CentOS 7, the *BEST* option is to back up your data, and do a fresh install.

I believe the OP just wants to download the RPMS which will then be installed on a (presumably non-internet-connected) CentOS 7 system.

michaelk · 03-03-2018, 09:37 AM

Quote:

I believe the OP just wants to download the RPMS which will then be installed on a (presumably non-internet-connected) CentOS 7 system.

Your correct, I did not pay attention to the OPs other thread.

fred2014 · 03-03-2018, 11:32 AM

damn - that will teach me to read the man page instead of typing --help !
I now see the man page on centos6 for yumdownloader is dated 2005....
that option didn't exist back then.

Thanks rknichols - if it does what it appears to do that should be the
final key to let me get this done.

Thanks to all.

F.

rknichols · 03-03-2018, 12:15 PM

Quote:

Originally Posted by fred2014

I now see the man page on centos6 for yumdownloader is dated 2005....
that option didn't exist back then.

I believe that "--releasever" falls in the category of, "inherits all other options from yum".

fred2014 · 03-05-2018, 03:40 AM

Yes - you're right - I think I must have been pronouncing it oddly when I first read it
because it didn't click as useful at all at the time - but I've been messing about a bit
more with yum and am starting to get the message.

Another issue has cropped up though but I'll start a new thread because its probably
worth thinking about in isolation anyway (xz compression)