What disk drives will work with the NeXT
There are some situations in which there are problems. Here is a short list which might help you in your disk drive quest:
These drives don't work with NeXT hardware: FUJITSU 2684SAU, SEAGATE ST51080N, IBM IB06H8891
The SCSI driver for NeXT hardware only accepts asynchronous data transfer. Although every new SCSI-2 drive should support this mode, this isn't true for certain drives. Also sometimes there is a hardware switch (a little jumper on the drive) which switches between synchronous and asynchronous mode. You definitely can only use asynchronous disks!
There are also problems with sync negotiation on NeXT hardware. In general there should be another jumper to toggle this are you might change this with an SCSI utility. There are also problems with the tagged command queuing option. Anyway all these problem can be solved. Often these problems arise with IBM drives. We recommend to look in the technical documentation of the drive, which is available only from IBM's WWW site directly.
Most SCSI disk drives will work without modifying /etc/disktab.
There are problems with the installation of boot blocks and badly formed fstab generated by BuildDisk of NEXTSTEP 2.0. A disk connected to the NeXT will need to have a NeXT specific label written to it before it can be properly recognized by the system. If you get an error message "Invalid Label..." this indicates that the drive was successfully seen by the NeXT machine but it does not have the proper label, to install a label use the /usr/etc/disk program on the raw disk device that the system assigned to the device and use the label command to write the label onto the disk. [how the NeXT assigns disk devices is explained in the N&SA manual]
NEXTSTEP releases 2.0 and up provide a low level disk formatter, sdform, which does not offer much flexibility, but gets the job done. Most drives are already formatted at the factory. You might look for the utility sdformat on the FTP sites as well, which overcomes some problems of sdform supplied by NeXT.