Boot from a SCSI HD

There are mainly 3 types of SCSI drives:

Single Ended (SE) SCSI
In addition to consideration for SE and LVD devices, you should take care in situations where mixing narrow and wide devices occurs. See Table 1.1 for data rates, and cable requirements. A Narrow device runs at 8 bits where a Wide device runs at 16 bits. If you use a Narrow device to terminate a Wide SCSI bus, only the Lower 8 bits will be terminated, and the upper 8 bits will not be terminated, which causes corruption and inconsistent behavior of SCSI devices. A Wide SCSI bus must be terminated with a Wide Active Terminator. This can be a separate terminator at the end of the bus, or a terminated hard drive. Active SE Termination has an impedance of 90 +/- 6 Ohms.

LVD SCSI
Ultra2 SCSI, also known as LVD (Low Voltage Differential) SCSI, uses the Differential standard for cable lengths and termination. On an LVD bus, the drives generally do not include a terminator, and adding an Active Terminator to the end of the SCSI cable terminates the bus. Again, remember that adding an SE device to an LVD SCSI bus causes the bus to revert to the SE standard. Active LVD termination has an Impedance of 125 +/- 10 Ohms.

Ultra 160 (Ultra3)
All SCSI-3 Standards beyond LVD will only be Wide, but will follow the LVD standard for cable length and termination.

•  LVD drives do not come with (any) terminators. Therefore, make sure you get one with your card, if you buy an LVD-capable adapter (which you should). Terminators are not cheap when purchased separately. 
  
  
•  Most/all current LVD-capable SCSI adapters come with auto-termination, which means the card sees what devices are installed/connected, and terminates (or unterminates) automatically. This is a nice feature, and you should look for it in a card. If not, you will have to manually set the card's termination (with jumpers), and this is one more place where you can screw up. Naturally, the less places where you can screw up, the better. 
  
  
•  The LVD terminator goes on the very last connector of the twisted-pair LVD cable. If you put the terminator on any connector (also called a position) other than the very last one, you will have what it called a dangling cable, which can generate signal interference, reflectivity, and other bad things. Before learning this, I have run my system with a 'dangling cable' and it seemed to run well. But everyone I consulted insisted that I place the terminator on the very last position. 
  
  
•  None of IBM Ultrastar SCSI hard drives came with the Write Cache Enabled (WCE). Enabling the write cache provides significantly better performance. I use Adaptec's EZSCSI 5 to enable the write cache on my IBM drives. (Thx to Joshua for that tip.) Apparently, the SCSI standards are tight enough that the Adaptec utility will work fine on a Tekram card. IBM also has a utility, but it is a POS (piece of cow manure), and will make your head hurt trying to use it. 
  
  
•  Seagate also makes a similar utility - far better than IBM's, but not nearly as easy as EZSCSI 5. For those with Win2000, you can go to the Disk Properties tab for the hard drive in the Device Manger, and put a check in the Write cache box. That will enable your write cache, too (very easy - and will stay for stay for Win98/ME, too).
  
  
•  Some people have problems with the write cache reverting back to its original disabled status after a reboot. I've gotten quite a few emails about this, and frankly, have no solution, other than use a utility made the the drive's manufacturer. I've never had this problem.
  
  
•  Enabling the write cache on the HDD allows the system to move on to the next task/function/operation, as soon as data is in the cache. If the write cache is disabled, the system must wait until the data is (actually) on the disk itself before it recognizes the write as complete. Because RAM/cache is several orders of magnitude (1 million times) faster than HDD disks, writing will take significantly longer. 
  
  Here is discussion from the Adaptec website. Microsoft has this to say about the subject.

There is a risk involved with enabling the write cache. If you have critical (system) data being written to the drive, and your system loses power after the data arrives in the cache, but before the data (actually) makes it to the disk, you could have serious problems. The chances for this happening are small, depending where you live, and the reliability of your local power company, time of year (summers are worst, due to high demand for electricity to run air conditioners, and therefore, even dependant on the weather. 

Worst case scenario = you could have to reformat & re-install your OS & apps. For this reason, it's a good idea to run a UPS (uninterruptible power supply). I use the BackUPS 650 by APC. 

Heard that some drives won't keep/hold the write-cache enable setting, using either the W2K check box or EZSCSI5. But I don't think this applies to IBM drives, cuz I have no prob with either method. 

None of my IBM Ultrastars (9LZX & 18LZX) came with Autostart enabled by (factory) default. You have to manually set this jumper (jumper config is spelled out on the IBM web site, and on a sticker attached to the drive itself). If you don't set the Autostart jumper, the drive will not power up when you press the start button on your PC. 

This can be a source of angst, especially if you just paid a good chunk of cash for it. Alternately, you can enable Send Start Unit in the (Tekram's) SCSI card's bios. This will spin up the drive when the SCSI bus starts its scan. But this will take a few more secs than setting the Autostart jumper. You want to set the Autostart jumper - at least on IBM Ultrastars. 

Update: just got a 36LZX which had the Autostart jumper set by default. Also the SCSI ID was set to 6 by default. Usually you'll want that to be set to SCSI ID 0. You do this with jumpers.

Be extra careful when setting SCSI ID jumpers, especially if when selecting an ID other than 0, and especially with IBM Ultrastars. (I have no experience with drives made by any other manufacturer.) It seems that IBM made the selection of SCSI ID's as confusing as possible. The numbers are backwards, right-to-left. Anyway, you'll see what I mean. SCSI ID 0 is easy, cuz you simply remove all the jumpers used to set SCSI IDs. But for any other ID, it can get confusing. Triple check your jumper settings with those for your drive at the manufacturers web site. 

I disable the start-up bus scan for all SCSI IDs except ones I'm actually using. This shaves a few secs from your start-up time, which can add up, over the months & years. But you have to remember to re-enable the bus scan for the ID of any new devices you add to the chain. Nothing like adding a new hard drive, or CDROM, & not having it show up, cuz you forgot to enable the bus scan. Doh!

For maximum compatibility, use Microsoft's FDISK to both partition & format both your SCSI and IDE drives. Forgetting to partition & format is one of the big Doh!s that people make with SCSI hard drives. They install it, see it in the BIOS scan, Windows sees it, but they can't access it. Still have to partition & format the drive. I use Microsoft's FDISK to partition, and have used Partition Magic a few times to modify things, to make room for Linux (ext2) partitions, and Linux swap(s).

Use Partition Magic to partition & format EXT2 partitions for Linux. Many use PM to partition SCSI & ATA drives. Nothing wrong with that, but I think MS FDISK has better compatibility, as more (that I know) use it.

For SCSI CD-ROMs & burners, for W98/SE/ME, you want to look in the device manager and enable Sync data transfer and Disconnect. I disable auto-insert notification, as it bothers CDRWin (burning app), but this is more pers pref If you want to disable AutoInsert notification in W2K, you need to use TweakUI, or at least I did. There is also a registry edit that will do this, but I can't seem to find it right now. 

I use 4GB for each of my Windows partitions (WinME & Win2000), and 1.8GB for each of my Linux partitions (Linux swap = 128MB). This is plenty (for me). I have each OS on a separate (physical) hard drive, but this is not necessary.

In order to run LVD devices in/with LVD mode/protocol, you need *every* part of your hardware config (to be) LVD-rated. In other words, to run your LVD/Ultra160 hard drive(s) in/with LVD mode/protocol, you need an LVD-rated adapter/controller, an LVD-rated cable (68-pin), an LVD terminator, and of course, and LVD/Ultra160-rated hard drive. So far, hard drives are the only storage devices capable of operating in LVD/Ultra160 mode. 

If any one of the previous components is not LVD-rated, then everything on the bus default to Single-Ended (SE) mode. Max SE transfer rate = 40MB/s. LVD/Ultra2Wide = 80MB/s. Ultra160 = 160MB/s, but this tends to be a misnomer, cuz the PCI bus can only handle max 133MB/s. I think I've already discussed this elsewhere, so will not beat a dead horse. Consider too, that the fastest drive out right now, the Cheetah X15-36LP, can only sustain a maximum transfer rate of about 60MB/s (!!).