jim@cdp.UUCP (02/05/91)
I'm looking for a way to do disk mirroring under SCO Xenix and SCO Unix without using a DPT or PSI caching controller. (Their controllers cannot be configured without at least 512K of cache). That probably means doing mirroring in software. Does anybody have any suggestions? Here's why I want mirroring without caching: I'm running Xenix 2.3.3 (Unix soon to come) on a DPT caching controller, and though it gives good performance, I believe I could get nearly as good or better performance using several SCSI disks and properly partitioning my files. Now that DPT (and PSI) support SCSI with their controllers, I could just switch from ESDI to SCSI and probably get the benefit of both a caching controller and overlap seeks. However, I've come to be uncomfortable with the concept of a caching controller. I'm running an important application (my boss might say they're all important) using Oracle, and I'm afraid that if the system accidentally gets turned off, recovering the database might be very difficult. Also, Oracle v6 redo-log files seem to be Oracle's Achilles' heel. If you lose one, especially the current one, it's nearly impossible to recover the database up to the moment of failure. Any other kind of crash can be recovered right up to the moment of the crash. So, I want to mirror a small drive containing the redo-log files and a few other important files, and put the rest of the file system and database on several other SCSI drives. Any suggestions or pointers would be appreciated. Jim Wampler jim@igc.org ..!uunet!pyramid!cdp!jim 415/490-3222 x445