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markus_b
Asked: 2012-06-19 01:39:28 +0800 CST

Loading multipath in SuSE install initrd for PXE

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I'm reinstalling cluster nodes with SLES11-SP1. The nodes are boot on SAN and will use the official RDAC driver once installed. But during installation (boot from the network using PXE) there is no multipathing driver present and therefore some activities, like the search for disks and partitions are very slow.

I would like to modify the SuSE-supplied network-install initrd to use dm-multipath during installation. Multipathing with dm-multipaht works and I have a multipath.conf file. I can add those to the initrd just fine. But I'm stuck in how to get the module loaded and the multipathd daemon started automatically during the install process. There is a program called 'init', which is the SuSE installer.

How can I get my 'modprobe dm-multipathd' and 'multipathd' started before handing over control to the install program named 'init' ?

installation pxe-boot sles sles11

1 Answers

  1. This is a bit of a guess, but I recently modified the initrd for Ubuntu 10.04 installer to add a new version of the Intel e1000e driver.
    I'd be quite surprised if you couldn't do something similar (in terms of modifying the initrd) to add multipath support to the SLES installer.

    The full instructions / walkthrough are here, but it basically boils down to using 

    zcat initrd.gz | (while true; do cpio -i -d -H newc --no-absolute-filenames || exit; done)

    to uncompress the initrd, and then modifying it, and recompressing it with

    find . | cpio -H newc -o > ../initrd.cpio
cd ..
gzip initrd.cpio

    Worth a shot, I suppose..

    Theoretically, once the module's in the initrd, you should be able to instruct the kernel to load it as a kernel argument in GRUB. GRUB can pass a module to the kernel with the module directive, as such:

    module /boot/module_to_load

    This might be interesting for you.

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