OLE case studies
OLE · Put your knowledge to work in context.
The Oracle Linux Engineer credential is aimed at administrators who run Oracle Linux in production and want independent evidence that they can install, tune, secure, and troubleshoot it without hand-holding. It suits sysadmins moving from another RPM-based distribution, database and middleware administrators who own the Linux layer under Oracle software, and cloud engineers operating Oracle Linux images. The OLE case studies are 5 cases and about 3,640 words.
1Online pvmove from a failing SAN LUN on a full volume group
A two-node Oracle Linux 8 database VM keeps /u01 on an XFS filesystem on logical volume u01lv in volume group vg u01. The VG is built from two 500 GB multipath LUNs, /dev/mapper/mpatha and /dev/mapper/mpathb, each on a separate array.
721 words, about 4 min2Emergency mode after SAN re-presentation plus an old default kernel
An Oracle Linux 7 server with root on LVM reboots to emergency mode after a SAN LUN holding /home was re-presented. The console shows 'Failed to mount /home' and 'Dependency failed for Local File Systems'; journalctl -xb shows a timeout waiting for the device with the UUID in /etc/fstab.
686 words, about 3 min3SELinux labels, a localhost backend port, and an over-broad firewall rule
An Oracle Linux 8 web server runs Apache with SELinux in enforcing mode. The application was moved from /var/www/html to /srv/app/public, and uploads go to /srv/app/uploads.
771 words, about 4 min4Mixing ULN, a stale internal snapshot, and a PHP module stream
An Oracle Linux 8 application server is registered to ULN and also has the public ol8 baseos latest and ol8 appstream repositories enabled. The internal standard requires PHP 7.4, but a recent dnf update proposes switching the php:7.4 module stream to php:8.0 and upgrading 612 packages, including glibc and the UEK kernel.
709 words, about 4 min5UEK defaults over RHCK and an unregistered Ksplice channel
An Oracle Linux 8 server runs a vendor application certified only on the Red Hat Compatible Kernel (RHCK) 4.18.0-477. A weekly dnf update installed kernel-uek-5.4.17-2136 and its modules.
753 words, about 4 min