SUMMARY: Lost Disk

Hi Guru's

I did not receive any responses to my query, but I managed to solve the
problem in any case, with some help from the vendor for the Disk subsystem.

I also logged a P1 Call with Sun, and though this equipment are not covered
by our support contract, they gave me some assistance with advice.
Unfortunately, they claimed that this is simply NOT POSSIBLE.

Yet, I managed to recover the disk fully.  The solution was to do the
following:

1. Use the HDS "Shadow-Image" function to create a "backup" of the
published LUN - just in case I screw it up.
2. Create a Completely new OPEN-E*x-SUN LUN having the same geometry as the
original, and make it available to the host.
3. Discover the new LUN on the host (reconfigure reboot required in most
cases)
4. Use "format" to label both the original and the new LUN.  The shadow
backup LUN is not touched.
5. Use vxdiskadm to initialize the new LUN.
6. compare the prtvtoc output for the original and new LUNs

At this point I have to note that part of what saved me was the fact that
all my disk encapsulation has been using defaults - no "special" tweaking.
If I had used special tweaking and had not documented it, it might have
been hard or impossible to re-create the VTOC.

7.  Pipe the prtvtoc from the "new"-ly initialized disk onto fmthard to
write a new VTOC to the original disk.
8. vxdctl enable
9. vxdisk list (voila!)


In the end, the HDS shadow image was just a backup - in case I screwed the
LUNs up.  However it worked without any problems.  Still, I say rather safe
than sorry.

One thing I did not mention in my previous email is that our NetBackup
master was one of the affected systems.  Our recovery team focused on two
parallel objectives: Recover the master and/or recover the disk LUNs to
avoid necessitating a restore.  We had just started importing tapes
manually into NetBackup (using newly allocated disk) when I managed to
successfully recover the LUNs.

Regards,
  _Johan







                                                                                                                                 
                    Johan                                                                                                        
                    Hartzenberg/G        To:     sunmanagers@sunmanagers.org                                                     
                    IS/CSC               cc:                                                                                     
                    @CSC                 Subject:     Lost Disk                                                                  
                    Sent by:                                                                                                     
                    sunmanagers-a                                                                                                
                    dmin                                                                                                         
                                                                                                                                 
                                                                                                                                 
                    16/07/2002                                                                                                   
                    10:31 AM                                                                                                     
                                                                                                                                 
                                                                                                                                 




Hi,

I have a severe problem and hope someone out there can help me.

It seems like one of the NT sysadmins by accident wrote signatures to the
SAN disk allocated to some UNIX systems.

My first question is how can I confirm this.

Secondly, is there a way I could try to copy the Solaris signature from one
disk on one of the systems which are still fine, to one of these "corrupted
disks" in the hope that the content of the LUN has not yet been erased?

The LUNs were under Veritas volume manager control.  The systems are a mix
of Solaris 2.6 and Solaris 8.  The disk subsystem is HDS 9960 and the LUNs
are formatted as HITACHI-OPEN-E*5-0117 (the "5" varies depending on size of
the expanded LUN)

Some of the LUNs used to be protected by SANtinel, which lost it's
configuration shortly prior to this incident - we still need to work out
why.

  _Johan
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