mediainit on a RAID disk system

[Jay Cantwell]

I need to run a mediainit on a RAID disk system. I am using the RAID system in a "just a bunch of disks" configuration. I realize that HP-UX looks at this as one drive. My problem is one of those disks was bad and had to be replaced and the manufacturer (TAG) did a low level format on all disks. Thus, my need to do a mediainit. Now for my question, which machine needs to do the formatting, the controller on the RAID system or HP. If the HP does it, do I use the normal mediainit command (mediainit -v /dev/rdsk/***)...

I am running HP-UX 11.0 and a TAG RAID disk system ....

thanks
Jay

[Stefan Farrelly]

Im not sure you need to do a mediainit. I think just a pvcreate -f on the /dev/rdsk/c... device would do, then add it into a VG..

Normally mediainit is used for single disks only (ie. the HP can see the whole disk - not a LUN which could be parts of many disks) and it is used to verify the media - mask out bad blocks etc.

I would try pvcreate -f first, if it doesnt work then try a mediainit -v on it (from the HP).

[Bill McNAMARA_1]

The disks can probably be added into a normal non raid enclosure and mediainitted, however, as pointed out, you shouldn't need to.

Typically, the raid system should have a mechanism to test and f/w upgrade each individual disk in the lun/array. This is not hp-ux's responsibility.

Perhaps you could try with mstm/xstm if their are expert functions available for the device, however, I don't know your array well, so can't be sure of that.

You should contact the array manufacturer. They'll possibly have s/w to do what you like.

Later,
Bill

[PIYUSH D. PATEL]

Hi,

I think that you need not do a mediainit on the disk. You can use the Disk array utilities if present. Just a pvcreate -f /dev/rdsk/c1t2d0 will do.

Piyush

[Jay Cantwell]

thanks everyone....I have not forgotten to assign points to your replies....I just want to try your ideas first and see what happens. Then I will come back and let you know....

thanks for all your help...

Jay

[Sanjay_6]

Hi Jay,

you should format the disk in the array using the array controller utilities. Then once you have created the lun, just do a pvcreate and proceed with your normal vg creation / restore. You should not have to do mediainit from the hp side.

Hope this helps.

Regds

[Jay Cantwell]

okay...now have the ioscan seeing the RAID as unused...however, SAM is not recognizing anything on there...it says the disk is unused....

I have tried to do a pvcreate
-f /dev/rdsk/c0t3d0 (device for the RAID disk) but it tells me that the device is assigned in the lvmtab already. Additionally, SAM will not set up a volume group for the same reason. Do I need to physically (using command line) go in and do a lvremove and vgremove and delete the file system entries from fstab?? then do a vgscan??

I appreciate any help I can get.....

Jay

[David Bell_1]

Jay,

You should be able to perform a vgexport for the volume group associated to the array. After that, you can move the /etc/lvmtab to /etc/lvmtab.orig then run vgscan -a. That should clear up the problem you describe. Once you've done that, run the previously mentioned steps "pvcreate -f". You should then be able to perform LVM functions normally. I don't believe it's necessary to do anything with the fstab entry. Should you find it to be a problem, edit the file and place a '#' in front of the associated entry.

When using SAM, you may find it doesn't work well with the device. In order for SAM to be able to perform functions, it typically will need an entry in the pd_devinfo.tx file. However, you may find it works fine. I'm not familiar with your particular array model.

HTH,

Dave