> 1. In rescue mode cciss.ko module was not loaded and i was try to load it but it was failed
The version of the cciss driver on your install media is probably too old, and a driver disk was used when installing the OS.
You'll need to use a driver disk with the rescue mode too.
> 2. Smart Array Controller displays one logical disk raid 1/0 and one is spared they are ok
> 3. physical disks are ok
Good, so your data might be recoverable, maybe even without too much effort.
> 4. it was "root=/dev/VolGrp00/LogVol00"
Looks like a default LVM layout - OK.
Go to http://www.hp.com/go/support and select "Drivers & Software". Type in your server model: "DL360 G5" and press Enter. You should get to a page that lists all the supported OS versions for the server model (direct link here).
Choose the RHEL version and architecture (32 or 64 bit) and you'll get to the download page.
Check the category "Software - Driver update": there you'll find the driver disk images for your OS version.
Click on the name of the download, not the blue "Download" button: you'll see a page that contains more information about that download, including the installation instructions. The procedure varies a bit between OS versions. Depending on the RHEL version, you might also be able to mount the disk image file with "mount -o loop,ro" on another Linux system and copy the contents (or even just the .dd file itself) onto a USB stick or burn it to a CD.
The RHEL Installation Guide for your RHEL version will have more information on all the different ways to use a driver disk image.
Then add "dd" to the rescue mode boot parameters (e.g. if you normally boot to rescue mode by typing "rescue" to the boot prompt, now type "rescue dd".)
The rescue mode system should now automatically prompt you to insert the rescue disk media in an appropriate point. With the updated cciss driver, it should recognize the controller and load the appropriate module automatically. At that point, you should at least see the partitions of the Smart Array logical disk in /dev/cciss/* and /proc/partitions. If your system is not too badly damaged, the rescue mode should now automatically mount the partitions to /mnt/sysimage.
When in rescue mode, all the LVM commands are packaged into a single binary named "lvm" to save space, so instead of "vgscan" and "vgchange -a y", you should use commands "lvm vgscan" and "lvm vgchange -a y". (If the rescue mode still fails to find your OS installation, those are the commands you need to try and activate the VG manually.)
If the rescue mode works with the driver disk and the partitions/logical volumes get mounted to /mnt/sysimage, the next step is to check the /boot filesystem (now /mnt/sysimage/boot). Each kernel file (vmlinuz-<version>) should have a corresponding initrd file (initrd-<version>.img).
If the initrd file for your current kernel is missing, it is easy enough to recreate it: first "chroot /mnt/sysimage", then "mkinitrd /boot/initrd-<version>.img <version>". Note that you will have to enter the kernel version string twice, and the string must exactly match the version string of the kernel file. After entering the chroot command, you should have all the normal RHEL system commands available to you, almost as if the system was in a normal single user mode.
If the rescue mode fails to mount your filesystems automatically, you may have to manually run a filesystem check (fsck) to one or more partitions and/or LVM logical volumes, then try again.
MK
