Installer has detected that the diskgroup name provided already exists on the system.

Hello,

After a failed crs installation, we have removed everything by using deconfigure and deinstall utility and freshly started the grid infrastruction installation, and we got this error

Checking Temp space: must be greater than 120 MB.   Actual 2395 MB    Passed
Checking swap space: must be greater than 150 MB.   Actual 32767 MB    Passed
Preparing to launch Oracle Universal Installer from /tmp/OraInstall2013-05-13_05-23-16AM. Please wait ...[FATAL] [INS-30516] Please specify unique disk groups.
   CAUSE: Installer has detected that the diskgroup name provided already exists on the system.
   ACTION: Specify different disk group.

Some background:-
1) Not using asm libraries or ASM lib disk we are just providing luns with udev rules

	[root@**** rsp_files]# cd /dev/oracleasm/disks
	[root@**** rsp_files]# ls -ltr

2) Partitions does not contain any valid partition table ,means no information written on the partitions

	fdisk -l /dev/mapper/asm1grid
	Disk /dev/mapper/asmt1grid: 10.7 GB, 10737745920 bytes
	255 heads, 63 sectors/track, 1305 cylinders
	Units = cylinders of 16065 * 512 = 8225280 bytes
	Disk /dev/mapper/asmt1grid doesn't contain a valid partition table

3) And my deconfigure clusterware and deinstall worked perfectly, no errors,

Where else could be the disk group information that installer is looking and failing?

Well, there is nothing much to scratch out our head, its just there in the lun headers and stayed there. So it wont use it any more we just need to scrap it out. To do the same dd command would be right choice.

          dd if=/dev/zero of=/dev/mapper/asm1grid bs=1048576 count=50 

A little explanation, i am padding my /dev/mapper/asm1grid lun with zeros of 1 mb block size and count of 50, this just an ideal , if you want u can add the blocksize also (solaris depends on the size of volume, linux 4096)

Then our installation proceeds without any issue. hope this helps to you as well.

-Thanks
Geek DBA