Hey everyone! I'm gearing up for an upgrade of our mixed OS environment and would love your advice on best practices, potential pitfalls, and upgrade paths. Here's a breakdown of what we're currently working with and our upgrade goals:
**Current Systems:**
- **Oracle Linux:** Several servers on **Oracle Linux 6.7**, plus a few older ones on **Oracle Linux 5.7** and **5.6**.
- **Red Hat:** A couple of servers on old versions like **RHEL 3.5** and **RHEL 4**.
- **CentOS:** Some servers running **CentOS 7.5.1804**.
**Upgrade Goals:**
- For Oracle Linux: Move everything to **Oracle Linux Server 8.10**.
- For Red Hat/CentOS: Combine and upgrade to **RHEL 7.9**.
I'm curious about a few things:
1. Is it better to do in-place upgrades, or should we opt for fresh installations?
2. What compatibility issues should we watch for when upgrading from these old versions?
3. Are there any good official guides or community resources for this kind of upgrade?
4. What are some common mistakes to avoid based on previous upgrade projects?
Any tips, experiences, or resource links would be super helpful. Thanks!
5 Answers
Honestly, I'd recommend starting fresh rather than dealing with in-place upgrades. Upgrading from versions like RHEL 3 and 4 is usually a major headache, and reinstalling gives you a chance to clean things up and test everything thoroughly. If you can, clone your systems into virtual environments first to make sure the upgrades won’t break anything. Just be aware that some packages might have different names in newer versions, which could mess with your old configurations!
Upgrading from such old versions can definitely introduce compatibility issues, especially with existing software. Transition or compatibility packages might help, but it can still get messy. A fresh install is your best bet for a smoother upgrade process. And be careful during the upgrade—package removals can lead to a cascade of issues if you’re not mindful of your dependencies!
Right, I'll make sure to keep an eye on those packages during the upgrade!
Going from Oracle Linux 6 straight to 8 can be complex, and you might face a lot of configuration challenges. I suggest cloning each system individually and testing the upgrades before going live. It’s also worth checking out the ELevate project, which aims to help with upgrades between major RHEL derivatives—it could save you a lot of hassle!
Thanks for the ELevate tip! I hadn’t heard of that one before.
I’ve had rough experiences with in-place upgrades, so I’d definitely lean toward reinstallation. It's safer and allows you to set things up the way you want without worrying about leftover issues from the old systems. Be sure to document your process, and definitely do backups and snapshots before you start—those can save you a lot of trouble if something goes wrong!
Good tip about documentation! Any advice on how to create a solid checklist for the process?
I would say go all the way to RHEL 9 when you're upgrading if you can. It'll give you a longer support lifecycle. Build new servers, get everything set up, and then migrate your apps over. This way, you minimize downtime and complications during the transition!
That makes sense! Do you think I should plan for some downtime during these installs?