James B. Byrne wrote:
How does one specify a particular version of a software package to yum to install? Is this even possible? What happens to superceded pacjkages in repos? Are they simple removed/discarded?
yum install package-X.Y.Z-A.el5 ???
The reason I ask is if a yum update goes awry for some reason then how does one revert to the previous (working) version? I seem to recall that up2date had a feature whereby one could locally archive superseded packages and rollback to a previous version was required.
I've spent some time struggling with this issue too. The current version of yum will let you specify an older version (as detailed in the man page) and install it - but you then have to be very careful with your `yum update`s to avoid accidentally upgrading it. Once you have a later version installed you cannot, currently, downgrade it - the only way to install an older version "over" an existing version is to remove the package and then explicitly install the older version, and this can result in some nasty dependency issues.
As has already been pointed out, this looks to be about to change in the next version(s) of yum in CentOS.
Regards -Laurence