I tried doing rootdisk mirroring in my local host , i added a new Ide disk in my system
and copied the prtvtoc from root disk to the newly added disk, and then when i tried to add database replicas on both the disks, it was added for boot disk but for the newly added disk i gave the error, which is like this:

 #metadb -afc 3 c0d0s7 c1d1s7
metadb: server : /dev/rdsk/c1d1s7: No such file or address

try this:

# metadb -afc 3 c0d0s7 c1d0s7

You say the disk is visible in format. Please post the output of format.

@DukeNuke2......Do you recognise these device names? I'm very familiar with c0t0d0s0 and c0d0p1 but not c0d0s7. (on Solaris)

What hardware is this?

a format output would be helpfull to clarify most of the open questions... also uname -a is maybe nice.

Thanks every one!!
Here are the outputs of format and uname -a

echo|format
0. c0d0 <DEFAULT cyl 3260 alt hd 255 sec 63>
/pci@0,0/pci-ide@7,1/ide@0/cmdk@0,0
1. c0d1 <DEFAULT cyl 1302 alt hd 255 sec 63>
/pci@0,0/pci-ide@7,1/ide@0/cmdk@1,0
2. c1d1 <DEFAULT cyl 1302 alt hd 255 sec 63>
/pci@0,0/pci-ide@7,1/ide@0/cmdk@1,0
3.c2t0d0 <DEFAULT cyl 1302 alt hd 255 sec 63>
/pci@0,0/pci1000,30@10/sd@0,0
4..c2t3d0 <DEFAULT cyl 1302 alt hd 255 sec 63>
/pci@0,0/pci1000,30@10/sd@3,0

uname -a
sun0S server 5.10 Generic_137138-09 i86pc i386 i86pc

On x86 devices names are c0d0p0 if they use fdisk partitions.
If they use slice, then it can be c0d0s0.
Drive c0d0 and c1d1 are different size? They have different amount of cylinders.
Post the output of:

# prtvtoc /dev/rdsk/c0d0
# prtvtoc /dev/rdsk/c1d1

With the 4 disks that are showing the same geometry I just wonder whether format is seeing the same 2 drives twice; or are there really four separate physical drives? (ie, 5 in all)?

Post the output of:

 
mount