0

I need a list of fixes for each recent CentOS release.

This feels like it should be simple, but I can't see a simple way to do it.

It's not hard to find the Centos release notes: https://wiki.centos.org/Manuals/ReleaseNotes

And, as an example, release notes for CentOS-7-1908 (currently the latest version of CentOS 7) are here.

Here's where my problem starts. Under Fixed Issues, it just says "For all the fixed issues it is best to look at the errata release page here and look for fixes dated starting Aug 6th 2019.", where 'here' links to: https://access.redhat.com/errata/#/

I'd prefer it if they explicitly said what they meant by 'starting'. Do they mean "starting then and going forwards" (since, inclusive) or "starting then and going backwards" (up to, inclusive)? Do they mean something else?

Given that CentOS-7(1908), AKA CentOS-7.7, was released in September, it seems reasonably clear that "starting Aug 6th", means "starting Aug 6th and going backwards".

Or perhaps they mean, to see what defects have been fixed since 7.7, look at anything with a fixed date of Aug 6th or later? That would imply that if a bug has a date of Aug 7, you can be 100% sure it wasn't fixed in this build, but a bug was fixed on Aug 5, then that bug might or might be present in 7.7.

It would be nice to know what they really mean.

Even if I assume that anything up to Aug 6 is fixed, and anything after is not, then I'm still only close to having what I want, which is to know what was fixed in 7.7 that was not fixed in 7.6.

If I could work out what's fixed in 7.6 and what's fixed in 7.7, then I could work out what's fixed in 7.7 but not fixed in 7.6. It wouldn't tell me when a defect was introduced, and it doesn't tell me anything about defects that haven't yet been fixed, but in this case, that's not important to me. YMMV.

But here are my other issues:

  1. There's no obvious good way to download a list from the webpage. I could scrape it, but that's ugly. Am I missing something?

  2. This is the RedHat errata page, not the CentOS errata page. I know CentOS and RedHat are more or less the same, but is it exactly the same? Comparing individual bugs between RH and CE, I can see that there's usually a couple of days before the CE bug gets fixed. Can I be sure that a RedHat build and the corresponding CentOS build both contain the same bugfixes, or is there a chance that a bug fixed close to the cutoff date might make it into one but not the other?

2

I need a list of fixes for each recent CentOS release.

They're posted to the CentOS-announce mailing list.

Do they mean "starting then and going forwards" (since, inclusive) or "starting then and going backwards" (up to, inclusive)? Do they mean something else?

Given that CentOS always follows RHEL, it must mean backwards.

As for whether it's mathematically inclusive or not, I doubt it, since that would imply that the work done for CentOS 7.7-1908 was done instantly upon the release of RHEL 7.7, which is impractical.

It is possible that Red Hat could ship one or more additional fixes later on August 6th after they shipped the RHEL 7.7 media, so they wouldn't be in the CentOS 7.7-1908 release made weeks later. I doubt this happens very often, but it's possible.

Or perhaps they mean, to see what defects have been fixed since 7.7

No. The whole point of the CentOS "release" system is that it is a checkpoint of the fixes made to the major release at a given point in time.

A key thing you have to understand about CentOS and RHEL is that these point releases are really just snapshots of the state of the package set made since the mid-2014 release of RHEL 7 / CentOS 7. If you installed CentOS 7.6 on a system on August 5th of this year and did a yum upgrade on it the next day, it should have approximately the same package set as if you'd waited to install that system using CentOS 7.7-1908 media.

Note the gap between RHEL and CentOS releases, though: you'd have had to wait about 5 weeks, until September 17th, to get the updated CentOS 7 media that corresponds to RHEL 7.7. As you noted, the stream of updated RPMs lags much less between the two OSes. If you installed CentOS 7.7-1908 on September 17th and then updated it, you'd expect to get a bunch of updates released during that gap.

The CentOS snapshot is made of the RHEL release, not of CentOS's own package update repository.

I'm still only close to having what I want, which is to know what was fixed in 7.7 that was not fixed in 7.6.

You're assuming that CentOS 7.6 was nailed in place from October 3, 2018 and never changed until CentOS 7.7-1908 was released on September 17, 2019, but that's not the case: CentOS point releases are just snapshots of the package set at a given point in time.

This is why CentOS names its releases as it does: 1908 is shorthand for August 2019, which is the approximate date of the snapshot. In that sense, there is only "CentOS 7" plus some number of updates.

The only reason RHEL and CentOS even make such point releases is so you don't have to install from the 2014 media and then download potentially years worth of updates to all of the packages made since then. Releases just let you save some download time if you're making more than one install during the point release's lifetime.

There's no obvious good way to download a list from the webpage.

I don't see a way, either. If I needed to parse info out of the announcements, I'd do it over my Maildir-formatted copy of the CentOS archives mailing list postings.

I know CentOS and RedHat are more or less the same, but is it exactly the same?

No, there's a time lag, owing to the time needed to re-build and re-test everything from the RHEL source RPMs.

CentOS point releases usually come out a month or so after the corresponding RHEL release, though sometimes this stretches to a few months. If you need the most timely updates, you need to be on RHEL, not CentOS.

Can I be sure that a RedHat build and the corresponding CentOS build both contain the same bugfixes

Yes, because CentOS is a rebuild from the same source RPMs, with changes only to branding and such. The difference is that time lag.

is there a chance that a bug fixed close to the cutoff date might make it into one but not the other?

Not when you're comparing point releases, since in the case of CentOS, it's a snapshot of the RHEL snapshot.

My point above about there possibly being a difference on August 6th is that Red Hat might release some post-7.7 RPMs that same day, which wouldn't be in the corresponding CentOS 1908 snapshot, yet would still be listed as "August 6th" on the errata page you pointed at early in your question.

  • Thanks for that. I've kept digging into the Errata pages. If the Issued date matches the "starting" date for a release (which is common), then the errata page mostly references the release note for that release. Otherwise, the "Affected Product" section of the Errata page will reference 7.6 or 7.7, if that was then latest release. Errata pages with dates between 7.5 and 7.6 tend to list 7.5, 7.6 and 7.7 for some reason. I haven't checked back further than that. – Ben Aveling Oct 28 '19 at 6:11

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.