Originally posted by: apple08

dear aix guru,
would lke to share my experience and seek your advice: this rack got 3 lpars. they wanted to setup a new lpar by adding new network card, fc card, 2 internal disc, activate 2 processor and trial one month memory. we down existing lpar and activated those new hardware components and they continue install base os cd on the new lpar. when want to bring up the existng lpar, two lpar can boot up correctly, but another one was booting up with no network configuration, all our data in our internal disc gone, password file has no our created id before this. even we want to go in the server, we need to go to maintenance mode and recover the root password. after go in we can't find all our files residing in the internal disc. and they check, the internal disc was stale (we have two internal disc mirror), but befor we down the lpar our internal disc is ok. do we miss anything? appreciate you advice, words how this kind miracle can happen. hope to hear from you. thank you.
#AIX-Forum

Originally posted by: apple08

dear aix guru,
from this experience, somehow i'm afraid to support any changes made to existing lpar. if you have experience or comments to the activity, would really appreciate your advice. many thanks in advance.
#AIX-Forum

Originally posted by: bassemir

I am not sure I understand completely your sequence of events but it sounds like you shutdown all three partitions and then created a fourth partition using new hardware that was installed. After building the fourth partition and installing the os one of the original partitions did not come back up.

Could it be possible that when the fourth partition was installed it was installed on one of the original disks in the system and not the new disks installed?

You mentioned you installed a fc card and two internal disks. If you were installing the os on one of the internal disks you would have to assign that storage controller to your new partition (unless you are using a vio server). Are you using a vio server to share the internal disks among partitions?

So you see I don't completely understand your environment but I could imagine how one could easily pick the wrong disk to use in a new installation.

Rich
#AIX-Forum

Originally posted by: apple08

dear aix guru,
thank for your reply. i was away from office. i think u understand our condition. we are not using vio server. we don't have vio server for these 4 lpars. u said how we can easily pick the wrong disc to use in a new installation (sir, how to prevent this). are you saying our environment is more vulnerable using vio server?

in this rack, we have shared cdrom and shared tape drive. they put the os cd inside the cdrom, i don't think we have move the cdrom to the new lpar. somemore during the activity, we have already boot up 3 lpars. and continue doing fresh installation on the assumed new lpar. if the cdrom is not assigned to the new lpar, will it caused the shared cdrom to overwritten our existing lpar (if currently that server is holding the cdrom).
hope to hear from you. thank you.
#AIX-Forum

Originally posted by: bassemir

Using a vio server will not make your environment more vulnerable.

When you are loading a new partition from cdrom the system will default to a hdisk, usually hdisk0. This is the disk the new lpar sees through the scsi adapter (or fc adapter) that is assigned to it in the lpar profile. You have the ability to take that hdisk or pick another by changing the installation choices (using the install menu).

If your new lpar has the ability to see hdisks that are currently being used by other lpars (I imagine this is might be possible if you are using SAN storage) you obviously want to pick an hdisk that is not used by one of your other lpars.

Rich
#AIX-Forum

Originally posted by: tony.evans

In fact, leaving the LPARs down while building new ones is the easiest way to screw them up, because with the LPARs down, you can happily allocate all their resources to a new partition.

If they're up, and you try that, your new partition won't start (or will start without those resources).

It does sound to me like the new partition was built using the SCSI adapter assigned to another host and that hosts disks.

CD drives can't 'float' between LPARs or be shared between LPARs. They can be assigned as a resource marked as not required, and then DLPAR'd around, but the first LPAR to boot will get the resource by default and others won't.

I'm not sure what happened was a miracle, more likely, someone used a resource they shouldn't in the new LPAR definition and built over the original disks.
#AIX-Forum