I am running an updated FC2 system.
My problem is that my raid modual is starting before my scsi modual and not auto-decting my software raid 5 on SATA disks (with scsi drivers).
Are you sure md module (RAID) is loaded before SCSI module? Check init script from initrd file. Something like:
$ mkdir /tmp/initrd $ cd /tmp/initrd $ gzip -dc < /boot/initrd-your-kernel.img | cpio -i $ less init
(you'll get some errors that you can ignore if you attempt to extract initrd cpio archive as normal user, ignore those, not important).
If modules in init script are loaded (look for insmod lines) in correct order, than you are one of few unlucky people that are hitting a known race condition. The problem is that device drivers when loaded are not waiting for each other to initialize completely. So when your SCSI driver is loaded, it starts to detect disk drives, and insmod command that loaded it exits while it is still doing that. md driver is than loaded, and if SCSI driver hasn't detected your disks by then, md driver isn't going to find them. Classic race condition.
If this is what happens to you, each time you install new kernel, you'll have to make custom made initrd image by editing init script, and insert "sleep 10" (or 20, or 30, whatever works for you) to give drivers enough time to initialize before next stage is invoked. Also, inserting sleep before/after udevstart is sometimes needed. On one system, I even had to do this for ext3 driver (sleep between loading of jbd and ext3 modules, sigh).
To do that, do this (this time as root):
# cp /boot/initrd-your-kernel.img /boot/initrd-your-kernel.img.orig # mkdir /tmp/initrd # cd /tmp/initrd # gzip -dc /boot/initrd-your-kernel.img | cpio -idmv # vi init (insert some sleeps between invocations of insmod) # find . -print | cpio -ocv | gzip -c > /boot/initrd-your-kernel.img
If you are using LILO, than you must do:
# /sbin/lilo
If you are using Grub, do not run /sbin/lilo !!!!! (or you'll screw up Grub).
This was also discussed on kernel mailing list. When I asked, one of the responses was that PCI is hot-pluggable subsystem, and that init script should (after it loads device driver) poll and wait for needed devices to appear (currently it doesn't, it just blindly loads driver after driver, and hopes that device will appear before next line that depends on it has been executed).
-- Aleksandar Milivojevic <amilivojevic@xxxxxx> Pollard Banknote Limited Systems Administrator 1499 Buffalo Place Tel: (204) 474-2323 ext 276 Winnipeg, MB R3T 1L7
