wales@CS.UCLA.EDU (03/15/88)
After trying for five days, I finally managed to get through to Fifth Generation's technical support people and asked for more information about the file compression bug in FASTBACK PLUS 1.0 (the bug which is reportedly fixed in 1.01). Here is what I found: The problem is that, under certain rare circumstances, a dump created with "data compression" cannot be restored properly. The tech support person cited the "save disks" setting for the "compression of data" option -- though I presume it could also occur if compression was set to "save time" (the default), since "save time" still does compression if there is time to do so. Only a few kinds of files are affected by the bug. The tech support person mentioned "overlay" and "font" files. I didn't ask (and he didn't say) what it was about these particular kinds of files that caused the problem. One can tell whether a given dump has been bitten by the bug by running a "dummy restore". To do this, select the "include files" option in the "restore" menu. Several input lines will appear at the bottom of the screen; by default, the first shows a directory name of "\". Delete this "\", making the input line completely empty. Then when you do the restore, FASTBACK PLUS will read the entire dump but will not put any- thing onto the disk. NOTE THAT A "DUMMY RESTORE" DOES *NOT* COMPARE FILES ON THE DUMP WITH FILES ON THE DISK!! This is *not* a functional replacement for the old FASTBACK's "verify files" restore option. All that happens is that the dump will be checked for readability -- and, if there is a compression problem, you will be informed. The only sure workaround (until FASTBACK PLUS 1.01 arrives) is to turn off data compression. To do this, first set the "user level" option to "advanced" (you have to do this in order to make the "compression of data" option appear in the "options" menu). Then select the "compres- sion of data" option, and set it to "off". FASTBACK PLUS 1.01 is being shipped now. The tech support person told me that all registered users should get it by the end of March. If you got FASTBACK PLUS via the "upgrade offer", you have been automatically registered and should get the new version whether you sent in the regis- tration card or not (he urged me, though, to send the card in anyway; I did so last week). As I said, I tried calling Fifth Generation for almost a week before I finally got something other than a busy signal or a "sorry, our hours are such-and-so, please call back then" recording. Once I got through to a tech support person, though, he was very polite, helpful, and knowledgeable-sounding. Toward the end of our conversation, I mentioned to him how much difficulty I had had getting through; he said they were aware of the problem and were working on getting new phone equipment and more tech support people (though when things would improve, he didn't say; it clearly wasn't something he had any control over). -- Rich Wales // UCLA CS Dept // wales@CS.UCLA.EDU // +1 (213) 825-5683 3531 Boelter Hall // Los Angeles, California 90024-1596 // USA ...!(ucbvax,rutgers)!ucla-cs!wales ...!uunet!cs.ucla.edu!wales "Sir, there is a multilegged creature crawling on your shoulder."