Hi I had to change the BusLogic to LSI disk controller (Maby to generic from LSI for instance), can someone point to me to a reference "how to change disk controllers"

My distribution is CentOs 6.4

Thanks and Regards

Can this be done?

Insufficient information! (Or I don't understand your question!!)

I used to change failed HP SmartArray RAID controllers; you needed to swap the battery backed up cache module between the faulty and replacement controller then power up the system to get back to an operational state. The RAID configuration is read from the small system partition on each physical disk within the RAID.

These were PCI cards, maybe that's not what you're asking?

You can't change integrated disk controller chips soldered to the motherboard unless you're VERY good at soldering and preferably have a hot air desoldering/soldering unit. The Chip will require to be EXACTLY the same as the one removed to guarantee pin for pin compatibility. Again, maybe that's not what you were asking.

If you've swapped controller cards, can you supply their Type and part numbers, maybe that bit of info would help otherwise I'm stumped?

Play Bonny!

Hi Soadyheid, thank you for the reply.

Since the post I have changed the cards and tried to play around. The system boots up and after the grub menu Kernel starts booting up but halfway it bombs saying unable to find the root disk and puts me in to a emergency mode. I think it is a driver issue (I am not an expert). I have been trying to understand but there was no simple document for dummies where it would say how to go about changing the Disk controller modules (if that is what I had to do). First question is can this be done if so appreciate if you can help on lest point me to a simple doc

Hope you understand my sutuation

Thanks and best Regards

OK, still not enough information.

From your last post I gather that you're talking about disk controller CARDS and you've swapped a (faulty?) one for a replacement of a different type? For your system to be guaranteed to work you'd need to swap like for like; same type and model as the faulty one. However... Your system's boot process is finding the grub menu so it's accessing a disk somewhere. Grub's just not pointing to your system as by changing the card you've probably changed the path to the bootable disk/partition. (My initial thoughts...)

Meanwhile... Other questions:

1.) How many disks have you in your system?

2.) If more than one, are they RAIDed?
2a.) If RAIDed, is it a hardware RAID (Which would be dependent on the controller card)

3.) Can you identify the controller cards; Part number, Spare part number or FRU number and post them for us? This information is usually on a small white lable somewhere on the card or on the copper etch. It would allow us to compare the cards which might be relevant.

Enough for now.

Play Bonny!

Hi Soadyheid, you are right a faulty card was replaced with a new one, I am out of office and will update as soon as possible

There is only one disk on the system, was using it as a test system

Thanks and best regards

Hi Soadyheid, sorry for the delay and I need to correct my self as well, the defective care was adaptec asa-7085 replased with LSISAS1064 PCI-X

is there any chance doing this by changing the drivers, is it possible at all?

Thans and best regards

I've had a quick Google of the card specs and have noticed a major difference between the adaptec asa-7085 and the LSISAS1064 PCI-X.

Though both cards support SAS disks, the Adaptec card fits in a PCLe x 8 channel slot, the LSI one fits in a PCI-X one. From this I'm deducing you fitted the LSI card in a different slot?

So... I reckon the path to the bootable system within Grub still points to the PCLe slot? Even though Grub gets "booted" its now looking at an empty slot for the disk and you get the " no system found" error. My theory so far.

There's a grub.cfg file on the disk under /boot/grub. The disk itself within this config file should be defined by its UUID which hasn't changed so that should be OK it's the path I'm wondering about. Grub2 has other files hidden elsewhere in /etc/grub.d I'd have to check on.

Unfortunately I'm going to now have to read up more on Grub2 to see how the boot sequence gets from the Grub menu to where the bootable system now lives.

Maybe someone with more knowledge of Grub2 can pick this up if it sounds like a valid theory? I'll check when I can, it's now a bit late here: 02:20am, I must be mad!

As for drivers? You may also be correct as the drive is now on a PCI-X bus rather than a PCLe one. (Note PCI-X is old technology now.)

Any other thoughts on this out there in LinuxQuestions land?

Play Bonny!

Thank you Soadyheid for the helping hand and linuxquestions has been quite a help when I was really stuck and only place where I could get a reply no matter how lame my questions be. Guess people like you keeps this place running

Its a long weekend here too, and I may have to let go of the server by next week for some production testing ! may end up reinstalling. I will try to reproduce the case and let you know, it is really intersting to know if we can change the driver card and get the thing running.

Thank you and best regards

A different card requires a different module as a driver. If the system is unable to find the root file system, that occurs after initrd is finished loading. It could be that the disk controller is working in a basic generic state to load grub and initrd, but to access the root file system it needs the specific kernel module. Most controllers will work this way for low level diagnostic and repair tasks.

You can boot the system from an install CD, launch a rescue chroot shell, and rebuild initrd. Then you can reinstall grub.

Hi AwesomeMachine thanks and will try, sounds a scare part to venture in to though, guess there is first for everything .

Best Regards

Hi AwesomeMachine, rebuilding initrd worked but having some trouble with the network does it have (when I try to start network it says unable to find eth0) anything to do with the rebuild

Thanks and Regards

Hi Guys, this worked after rebuilding the initrd, thanks you both! and best of regards