Yep, your updates are good, and in keeping with the opening sentences of 
my reply:
> There are probably going to be a large number of replies based on 
everyone's own personal experiences. 

Then add to more to item 2d. (if your pockets are deep enough):
"Ship either duplicate tapes, or the two most recent day's worth BY 
SEPARATE PLANES and SEPARATE TRUCK."

We used to ship the two most recent day's worth BY SEPARATE PLANES.  If 
one shipment was delayed (or a tape was bad), we could test with the other 
day of tapes. 

Then we heard of case where all the tapes from both planes ended up on the 
same truck for a DR test and that truck went off a bridge, destroying some 
tapes and delaying the rest beyond the D.R. test window. 

After that there was a rumor (unsubstantiated) of two truck drivers at the 
delivery airport having their tapes loaded at the same time.  They loading 
was complete at the same time.  They competed to see who could get the 
tapes to the D.R. site first, running into each other during the spirited 
race from the airport.  I never heard more details and suspect a techie 
folktale, but even if it's not true it's good to at least consider.

My carry-on luggage always contained about 12 recent hand-made (outside 
the normal schedule) backup cartridges of the sysres and program product 
DASD.  One time when a tape was missing from the shipment, we were able to 
continue with the D.R. test using the carry-on tape.  The postmortem 
report included a note that the (expensive) test would have been a failure 
had we not hand-carried our own copies.  Never had another missing tape 
after that.

Since then we opened a second data center about 3 miles away as the crow 
flies, with mirrored DASD.  A D.R. test now is just 'cutting the link' 
(done by the DASD vendor) and IPLing the mirrored DASD (at the same 
address!) from a CEC in the surviving data center.  Sure makes D.R. tests 
a piece of cake.  The z/VM system that we recover is generally IPLed and 
ready for users about 10-20 minutes after we're given the LPAR (need time 
to update a few CPUID-dependent product config files).  The users complete 
testing in about an hour, we shutdown and go home to sleep.  Niiiiice! :-)

Mike Walter
Hewitt Associates





"Ivica Brodaric" <[email protected]> 

Sent by: "The IBM z/VM Operating System" <[email protected]>
12/14/2009 04:39 PM
Please respond to
"The IBM z/VM Operating System" <[email protected]>



To
[email protected]
cc

Subject
Re: VM Best Practices






2) Keep automatically produced  daily reports to minidisk, printed to
hardcopy at least weekly, showing:
a)  the current location of critical minidisks.  The list should be
quickly searchable by sorted userid and mdisk (e.g. "Where's MAINT's 02C2
disk with the "USER DIRECT" file? Or... the appropriate DIRMAINT,
VM:Secure, etc. source directory disk)?  Where's the backup catalog disk
located?
b) what's located, and where, on each real DASD (e.g. DASD VMU001 was
trashed, what did we lose?).
c)  the allocation bitmap on each DASD.  That will show the DRCT, PAGE,
PARM, PERM, SPOL, or TDSK allocations when you don't have a way to look
back at what once was.

It's a good list, but I would add under (2):
d) If you are sending the backup tapes to offsite storage, make it a part 
of operations procedures to produce these critical reports in hardcopy and 
send them *with* the tapes offsite. Be prepared to do a DR test using only 
the contents retrieved from the offsite storage and a DR procedure manual 
stored at the DR site. Empty your pockets, please... OK, a pen is allowed. 
;-)

Ivica




The information contained in this e-mail and any accompanying documents may 
contain information that is confidential or otherwise protected from 
disclosure. If you are not the intended recipient of this message, or if this 
message has been addressed to you in error, please immediately alert the sender 
by reply e-mail and then delete this message, including any attachments. Any 
dissemination, distribution or other use of the contents of this message by 
anyone other than the intended recipient is strictly prohibited. All messages 
sent to and from this e-mail address may be monitored as permitted by 
applicable law and regulations to ensure compliance with our internal policies 
and to protect our business. E-mails are not secure and cannot be guaranteed to 
be error free as they can be intercepted, amended, lost or destroyed, or 
contain viruses. You are deemed to have accepted these risks if you communicate 
with us by e-mail. 

Reply via email to