SCSI Hard Drive Testing
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This document assumes you are familiar with how Free Geek tests/wipes IDE & SATA HDs.
First triage the HDs here SCSI Hard Drive Triage
Overview of the test station
We have an external enclosure for testing up to 12 "80-pin" HDs (connector shaped like a hollow "D"). Also, we have an internal cable, & power supply extender, with room for up to 4 "68-pin" HDs (also "D" shaped, but with pins).
NOTE: Our current test script has trouble displaying the in-progress detail for more than 5 or 6 HDs, so, even tho' we could test up to 16 HDs on this test station, doing only 5 or 6 is easier to manage. Also, testing more than 5 or 6 72GB HDs can take 20+ hours to finish, so schedule accordingly.
There are usually no jumpers on the 80-pin HDs that go into the external enclosure, the enclosure jumpers them. If there are any, remove them all. As for 68-pin HDs, where IDE HDs are jumpered "Master" or "Slave", SCSI HDs are jumpered numerically "0" thru "15". There will be diagrams on the HDs, which is good, because the patterns run from left to right OR right to left (just like with IDE HDs).
Setting ID Jumpers on 68-pin drives
There will be 4 jumpers, labeled "0 1 2 3" or "1 2 3 4" or "1 2 4 8". Jumpering a combination of these will give IDs of 0 thru 15. Think of the "1 2 4 8" pattern: no jumpers gives 0, all 4 jumpered gives 15 (1 + 2 + 4 + 8), jumpers on 1 & 2 gives 3, jumpers on 1 & 4 gives 5, jumpers on only 1 of the 4 gives 1 or 2 or 4 or 8.
IMPORTANT NOTE = do NOT jumper an HD to 6 or 7, these are used by the controller cards (some cards use 6, others use 7). If you do, the HD will not be recognized, thus giving a false negative.
68-pin SCSI HDs often have a 2nd set of jumpers. These are not for ID numbers, but rather for settings like termination, spin delay, & other SCSI-specific & esoteric things we usually do not care about. REMOVE all jumpers from this pin array. Then, read the pin diagram, looking for "Motor Enable", or a similar phrase. Usually the HD will "spin up" & be recognized without this jumper, but if not, try adding a jumper here.
Howto Tell Which Drive Is Which
The test script currently has trouble finding serial numbers for SCSI HDs. If you are testing drives ONLY in the external enclosure OR on the internal cable, this is no problem:
For drives in the external enclosure, the enclosure "jumpers" the drives from bottom to top, so if you load 12 drives, they will be read by the script as "sda" thru "sdl". For drives on the internal cable, the drive jumpers control the script's order, for example: drives 0, 1, 2, 4 are "sda, sdb, sdc, sdd".
IMPORTANT NOTE !
When you test both internal & external drives, the EXTERNAL enclosure is read FIRST. Example: you have 3 drives in the external enclosure & 3 drives on the internal cable, so the EXTERNAL drives will read as "sda" thru "sdc", & the internal drives will read as "sdd" thru "sdf".
Test Station Repair & Maintenance
This will become a full discussion of hardware inventory for a SCSI HD test station. Mostly this will matter when an internal cable wears out.
Do not connect the internal & external cables to the same controller card, as this creates the risk of having 1 of 2 HDs be invisible because they are jumpered to the same ID on the same channel, thus giving a false negative. It can be done, but it's tricky because there is no standardization RE which connectors are on which channel. Basically, when swapping cables, plug the new cable into the same connector the old one was on.