DSF

[Ravikant]

HI All,

We have two HP servers running with 11i V3 OS.
Oracle team tryign to setup a ORACLE RAC setup on the same. For ORACLE RAC setup they need to have same DSF name for the raw devices.

How we can change and make the same DSF name on both the servers.

Regards,
Rav

[Fabio Ettore]

Hi,

AFAIK lan cards must have the same name, I mean for example they have the same name lan10 on all nodes, nothing about raw devices name.

Best regards,
Fabio

[Ravikant]

Sorry for more details -

We have a shared SAN disk for oracle RAC. Instead of VG creation they are directly using that disk as a raw device for RAC setup. Since it is shared among two nodes. Both the node shoowing different as DSF.

Can we have same disk name on the nodes ?

pls revert in case of more info.

[Fabio Ettore]

By having the same DSF do you mean Legacy or Persistent DSF?

Legacy is so: /dev/rdsk/cXtXdX
Persistent is so: /dev/rdisk/diskX

They're two different things, even though they're correlated each other.

Depends on what you mean, you could change Legacy device files by Instance Number with a tool named ioconfig_dump provided by HP.
You could change persistent ones by io_redirect_dsf but in that case another device file must exist. Folows an example from man io_redirect_dsf:

Redirect the DSF /dev/disk/disk23 to point to the device with DSF
/dev/disk/dsk26. Both DSFs represent devices that belong to the disk
class .

io_redirect_dsf -d /dev/disk/disk23 -n /dev/disk/disk26

Best regards,
Fabio

[Ravikant]

Hi Thanks for the information.

I am looking for persistent DSF.

On one node it is showing /dev/rdisk/rdisk23 and on the second node it is showing /dev/rdisk/rdisk26 for the same storage LUN.

With io_redirect_dsf command we can change it to only those name which are already present. But is there any way wherein we can have same persitenet DSF on both the nodes whch are not present..

Thx..Rav

[Turgay Cavdar]

Hi,
Create new device files with standart names.On both nodes, first get the major minor number of the disk:
#ll /dev/rdisk/disk10

Create directory for new DFS:
#mkdir /dev/oracle

Create new device files:
#mknod /dev/oracle/raw_dbname_asm1_120g c 22 0x00001e (major/minor numbers belong to original disk)
#mknod /dev/oracle/raw_ora_ocr1_1g c 23 0x000019
#mknod /dev/oracle/raw_ora_vote1_1g c 23 0x00001b

Change permissions/owners For OCR disks:
#chown root:dba
#chmod 640

Change permissions/owners For Voting and ASM disk:
#chown oracle:dba
#chmod 660

[Ravikant]

so what will be the persistent DSF o/p.here.

They need in the form of /dev/rdisk/disk26 on both the nodes.

Can you please elaborate more on the mentioned process, we need to perfom on both the servers ?

Thx a lot for your help..

Rds. Rav

[Fabio Ettore]

Hi,

if it's not already present I don't know how you can do. In the past I tried something by ioconfig_dump but I couldn't use it for persistent device files.

If you really need to have the same persistent files between systems I suggest asking HP how to do that without having already it in place, I'm not sure a way does exist currently.
I also tried something by mksf but without success.

Though I'm still not sure you really need to have the same raw device file between systems in a Oracle RAC environment, as mentioned I know you must only have the same lan definitions.

Best regards,
Fabio

[Turgay Cavdar]

Hi,
The form "/dev/rdisk/.." is not necessary you just need to give /dev/oracle path to dba admins, and they will use this path as ASM_DISKSTRING.
As we create new device files basing on persistent DSF, they are perssitent too... You can check and see with ioscan -m dsf that the new device files are under "Persistent DSF".