The mirrored dasd would be nice. However, we do not have it yet. What we do have is writing backups to remote tape units. We do Hidro backups to them because of the speed and lesser line charges. We maintain 5 generations of the backups. When the backups complete, we send a note to a distribution list that includes people at both data centers and at the left-coast site, giving us at least two copies at each of three locations that are from each other by more than 1000 miles. The note contains a listing of all tapes that are available, most recent date first, and a complete set of instructions for restoring the system.
We have recently tested the process and will do so annually, even if we change it to use mirrored dasd instead of the tape backups. I hear rumors that it might happen in the next few years, but will not hold my breath while waiting for it. Regards, Richard Schuh > -----Original Message----- > From: The IBM z/VM Operating System > [mailto:[email protected]] On Behalf Of Mike Walter > Sent: Monday, December 14, 2009 3:13 PM > To: [email protected] > Subject: Re: VM Best Practices > > 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. 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