Database recovery delivered
May 19, 2008
All databases can become useless. That is, they suffer some kind of corruption or acquire an unwanted flag. The latter problem came to visit an HP 3000 site over the weekend. The solution to repair a 3000 database ultimately arrived from Adager, the resource the 3000 community calls when trouble needs fixing pronto. James Dunlap called out to the community, via the 3000 newsgroup:
I was increasing a dataset’s capacity using DBCPLUS and thought my (remote) session had hung after already doing PER COM, so I aborted the session. The bad news was that we don’t have a current backup of the database, and now the “restructuring” flag is set and the DB is “bad.”
That's HP's DBChange Plus utility that Dunlap is using, a tool HP obsoleted. In this situation, DBCPlus played a part in making the database bad. Old tools might be better than no tools; HP tried to put its customers in touch with third parties in 2000 when it dropped DBCPlus.
Dunlap tried to make a copy of the database too, and the copy was also “bad”. He reached out to the community through the Web, although finally the solution came through a call to Adager.
Resetting the database flag advice came from Craig Lalley of EchoTech:
You can reset the "restructuring" flag. There are several ways to do it, none come to mind here in the airport, but I would start with DBUTIL. Do you have Adager, or [Bradmark's] DBGeneral? It is a two bit marker that you should be able to find with DEBUG.
But if you're not familiar with running DEBUG on an HP 3000, the tool can become a tar pit. You'll want expert advice to fix a database problem using DEBUG, a tool on every HP 3000. Custom programming might have solved the problem, according to Brian Donaldson. But he couldn't resist fundamental advice on database procedure: "I don't mean to sound unfeeling about your predicament, but you are getting everything you asked for -—"
1) Not having a backup copy of the DB prior to making structural changes
2) Not using Adager for structural changes to begin with
3) Doing these structural changes across a remote line is just asking for trouble!
You can write a quickie Privileged Mode program to FOPEN the Image root file, read label zero and reset offset zero to a value of "FW" (which means database okay and accessible.) Definition of the root file is in the blue Image/3000 Handbook.
Donaldson's fix carried three notable pieces of information. First, there's the use of a Priv Mode program, written to work in the deepest level of MPE/iX. A process not for many a 3000 owner. Then there's the Image/3000 Handbook, a community resource long out of print but on the shelf of savvy, seasoned 3000 experts.
Then there's that FW flag. The FW stands for Fred White, co-creator of Image. After leaving HP, White worked at Adager for many years before retiring. And so Dunlap found his answer at Adager:
Rene Woc at Adager walked me through the necessary steps to fix via Debug. (FW did the trick.) That was not only kind of him, but downright gracious, considering that we don’t have Adager (yet!). Thanks to all who helped.
HP 3000 help remains available through the Web. It is likely to be around long after HP closes its support doors for the system, delivered by way of third parties like Adager. "We remain surprisingly busy," Woc told me in a call last week. He monitored HP's Webcast last week online, staying up to date with HP's plans to curtail 3000 support.
Dunlap reported his repair process, a resolution via Adager expertise: