5 ms·

I tried this back in the RHEL 6 days. Do not recommend. They changed things just enough that you can't just drop in RHEL and expect drivers, performance, and o

I tried this back in the RHEL 6 days. Do not recommend. They changed things just enough that you can't just drop in RHEL and expect drivers, performance, and other kernel-level stuff to be the same. Now I understand why, it was to better support their database. But it was frustrating to deal with unless you were going all in with them and planned to pay them for systems that needed support. Has this changed?

chasil 6y ago
I ran the conversion long ago with Red Hat 4, and there were no problems. I've heard one report elsewhere of a smooth CentOS 8 conversion. Oracle Linux 6 includes two kernels - the RHCK (Red Hat Compatible Kernel), and the UEK (Unbreakable Enterprise Kernel). Which one were you using? I think Oracle only commits to userland compatibility with RHEL, but perhaps not kernel drivers under either distribution kernel.
- fl0wenol 6y ago
  That takes me back. Yes, we could not use the UEK so we tried using the RHCK. But we were still running into issues trying to debug kmods that we weren't running into on CentOS. I guess we weren't in the target market there for Oracle. It left me with a negative impression that maybe is unwarranted, but I've had plenty of other bones to pick with Oracle so I would be very cautious in depending on them for a platform. See Java as an example. OpenJDK (and IBM/RHEL, ironically) is the only thing keeping that from turning into a bigger support trash fire.
  - chasil 6y ago
    I will tell you two things about RHCK compatibility. First, Oracle's RHCK worked properly with the ZFS source code when I wrote this, and I'm assuming that it was built for Red Hat: https://www.linuxjournal.com/content/zfs-linux https://www.linuxjournal.com/content/zfs-linux Second, it would likely be possible to run the CentOS kernel on Oracle Linux. My research for Btrfs ran the other way, but I was able to get both the latest Fedora and Oracle UEK kernels working on CentOS with various levels of Btrfs support. https://www.linuxjournal.com/content/btrfs-centos-living-loopback https://www.linuxjournal.com/content/btrfs-centos-living-loo... I don't think it's necessary to use an Oracle-supplied kernel package on Oracle linux; kernel packages from other distributions would likely work.

chasil 6y ago

I ran the conversion long ago with Red Hat 4, and there were no problems. I've heard one report elsewhere of a smooth CentOS 8 conversion. Oracle Linux 6 includes two kernels - the RHCK (Red Hat Compatible Kernel), and the UEK (Unbreakable Enterprise Kernel). Which one were you using? I think Oracle only commits to userland compatibility with RHEL, but perhaps not kernel drivers under either distribution kernel.

fl0wenol 6y ago
That takes me back. Yes, we could not use the UEK so we tried using the RHCK. But we were still running into issues trying to debug kmods that we weren't running into on CentOS. I guess we weren't in the target market there for Oracle. It left me with a negative impression that maybe is unwarranted, but I've had plenty of other bones to pick with Oracle so I would be very cautious in depending on them for a platform. See Java as an example. OpenJDK (and IBM/RHEL, ironically) is the only thing keeping that from turning into a bigger support trash fire.
- chasil 6y ago
  I will tell you two things about RHCK compatibility. First, Oracle's RHCK worked properly with the ZFS source code when I wrote this, and I'm assuming that it was built for Red Hat: https://www.linuxjournal.com/content/zfs-linux https://www.linuxjournal.com/content/zfs-linux Second, it would likely be possible to run the CentOS kernel on Oracle Linux. My research for Btrfs ran the other way, but I was able to get both the latest Fedora and Oracle UEK kernels working on CentOS with various levels of Btrfs support. https://www.linuxjournal.com/content/btrfs-centos-living-loopback https://www.linuxjournal.com/content/btrfs-centos-living-loo... I don't think it's necessary to use an Oracle-supplied kernel package on Oracle linux; kernel packages from other distributions would likely work.