00109: File corruption under DOS, Windows, Novell

Title:

File corruption under DOS, Windows, Novell

Description:

File corruption can be a problem under DOS based platforms because it is very easy for a user to reboot the system when BBx has files open. This is potentially hazardous, and DOS is not as robust as Unix when it comes to handling this type of situation. 

Resolution:

The first step in prevention is to always exit BBx properly. If BBx is not allowed to exit properly, any open files may be left in a partially updated or unknown state. This can happen when a user reboots the system, a power failure shuts down the computer, Windows hangs/reboots, etc. 

Secondly, you can set byte 2, bit $01$ in the setopts so that BBx will attempt to force MS-DOS to update the length of an dynamic file such as an MKEYED file after any growth in the file. 

Another method for prevention is the use of lock files on the terminal alias lines. Here is an example: 
        alias T0 /dev/con doscon driver=pcvga.drv,dma,mode=3,lock=c:/temp/lock.T0 

With this alias line in place, BBx will attempt to create the lock file c:/temp/lock.T0 (note the orientation of the slashes) whenever it is invoked as T0. If the lock file does not exist, BBx will create it and then remove it when BBx exits. If the lockfile is already there, BBx will not load and will give an FSLoad Error 15, signifying the existence of the lockfile. This information can then be used as a warning that the last time T0 ran BBx, they did not exit properly and any files that they may have had open are candidates for corruption. 

Lastly, BASIS also supplies a utility, _FIX in the std directory, that can be used to recover a corrupted file. This utility is to be used only when restoring from the most recent backup is not feasible. 

Note: Some large Seagate drives come with a write-cache bit enabled, which cannot be used under Novell. These drives caused a lot of file corruption. As soon as the drives were replaced with drives without the write-caching, all file corruption disappeared. 

Note: It has been reported that turning off the Write Cache feature in the Novell 32bit Client kit has helped solve re-occurring error 7’s. This setting is under Control Panel, Network, Novell Client, Properties – under the Advanced options. 

Last Modified: 03/23/1998 Product: PRO/5 Operating System: MS Dos Windows NovellError Number: 7

BASIS structures five components of their technology into the BBx Generations.