If you have several of the same brand like Emu, Roland, Peavey. etc you can share your hard drives, etc. It's not a good idea to hook them up in a single daisy-chain, but you may get by if you have only two samplers and they can be set to different SCSI IDs/addresses. Otherwise You should get a SCSI switcher. It's a little box that could save you from crashes and the hassle of constantly reaching behind your rack to change cables. You need to make sure the box you get is SCSI not serial and has the correct number and type of connections. This switcher allows multiple samplers to access a single array of hard drives or CD-ROM drives on the same SCSI bus. The SCSI bus was never meant to host more than one operating system at a time, so when daisy-chaining works at all, consider it a happy accident.
A SCSI switcher sets up your gear in a "star" or "hub" system where each sampler becomes a separate spoke on a wheel. By switching the knob on front of the box you're selecting which sampler has access to your hard drives, etc at that time. You can't switch while the hard drives are saving or loading sounds. If you want to switch samplers on the fly, you need to make sure the switcher is an active one. This allows you to safely change from one sampler to another without having to reboot the system after you have flipped the switch.While more expensive they will save you from crashing or causing you to lose valuable sounds or data. Passive switchers can be used but it recommended to power off then switch the SCSI bus then power on, doing it on the fly is dangerous to the hardware in your system.