Using "raw disk" for Informix on UNIX

After reading the Informix Online 5.0 Administrator's Guide, we decided to use raw disk instead of "cooked" disk for our 1GB database on an NCR 3430 machine running UNIX System V Release 4. We were a little apprehensive, but after figuring out that the boot sector uses 34k on our 1GB+ SCSI hard disk, we specified that the database should use all but 100k of the total space. Everything initialized fine (although it took quite a while), but when we run tbinit the following messages have begun to appear on our console: Warning: cs.c: Unrecovered Medium Error (0x000112f1) on Major Number 35, Minor Number 32 Warning: cs.c: Unrecovered Medium Error (0x000112f3) on Major Number 35, Minor Number 32 Warning: cs.c: Unrecovered Medium Error (0x000112f7) on Major Number 35, Minor Number 32 Warning: cs.c: Unrecovered Medium Error (0x000112f5) on Major Number 35, Minor Number 32 Warning: cs.c: Unrecovered Medium Error (0x000112f1) on Major Number 35, Minor Number 32 Warning: cs.c: Unrecovered Medium Error (0x000112f1) on Major Number 35, Minor Number 32 This database is going to contain critical data, so we are very worried about this symptom. We'd appreciate it if anyone has experience with this and has any advice to help us out with this problem. -Sohail