anaconda failing to install Linux over dual paths

During network installs of Linux, we have 2 HBA connected to the SAN. Each provides one or more LUNs for the OS and data, as we boot from SAN. However, we have had a lot of problems with the visibility of these LUNs to the (anaconda) installer of Oracle Enterprise Linux (OEL) 4 update 5 (4U5). The current version gets confused by disks being visible twice and can't distinguish between them. So it overwrites over the second path what it already did over the first.

Our current work-around was to either shutdown the FC port of one of the HBA cards on the FC switch. Another is to hide LUNs on the second HBA during install and reactivate them afterwards. However, both these cause extra manual work and unnecessarily increase complexity of the whole setup.

Another solution that we're testing is to only hide the boot LUN on the second HBA, not the whole set of LUNs. Anaconda (wiki) seems to have an issue writing to disks that are visible over more than path, no reading from them. Apparently, OEL 5 will have a new version of anaconda that is aware of multipath I/O devices. However, this will force us over to a major new version of the OS, so we're not sure if it's worth the change...

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