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- Newsgroups: comp.os.linux
- Path: sparky!uunet!gatech!usenet.ins.cwru.edu!agate!boulder!ophelia!drew
- From: drew@ophelia.cs.colorado.edu (Drew Eckhardt)
- Subject: foo
- In-Reply-To: <C0JqMH.J3D@ra.nrl.navy.mil>
- Message-ID: <1993Jan11.075144.21912@colorado.edu>
- Sender: news@colorado.edu (The Daily Planet)
- Nntp-Posting-Host: ophelia.cs.colorado.edu
- Organization: University of Colorado at Boulder
- References: <C0JnHJ.1Hvz@austin.ibm.com>
- Date: Mon, 11 Jan 1993 07:51:44 GMT
- Lines: 103
-
- In article <C0JqMH.J3D@ra.nrl.navy.mil> you write:
- >In article <C0JnHJ.1Hvz@austin.ibm.com> mwpoag@thurston.austin.ibm.com (Michae
- l Wayne Poag) writes:
- >> 1) send the spin-up code to a drive on an st01
- >> 2) activate a drive added after boot-up
- >>
- >>I am running v.98p1 of HJ Lu's distribution
- >>The st01 is recognized, and the drive too, but this drive has
- >>no jumper for spin-up on power-up...
- >>
- >>Is there any new scsi code in the newer kernels that would help.
- >
- > I am not aware of any special scsi command to spin up a drive, so I
- >guess the answer is that the newer kernel is unlikely to help you much. I
- >grepped the scsi specifications for variations on "Spin up", and came up empty
- .
- >All I can suggest is that you contact the manufacturer and find out what is
- >needed - it is possible that there is some kind of drive specific command that
- >must be sent before the drive spins up.
-
- There is a standard SCSI command for this. Some drives are configured so
- that they don't spin up on power up, and instead wait for the START STOP UNIT
- command (Most notably, DEC does this with their discs on their
- Decstations). In some cases it is jumper selectable (some HP disks),
- or software configurable on one of the mode pages (some DEC disks).
-
- The command you want is opcode 1BH, START STOP UNIT.
-
- Note that the semmantics are slightly different for SCSI-I/SCSI-II -
- SCSI-1 specifies the LoEj bit as reserved (so it should be set to zero).
-
- 8.2.17. START STOP UNIT Command
-
-
- Table 8-33: START STOP UNIT Command
-
- ==============================================================================
- Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
- Byte | | | | | | | | |
- ==============================================================================
- 0 | Operation Code (1Bh) |
- -----|-----------------------------------------------------------------------|
- 1 | Logical Unit Number | Reserved | Immed |
- -----|-----------------------------------------------------------------------|
- 2 | Reserved |
- -----|-----------------------------------------------------------------------|
- 3 | Reserved |
- -----|-----------------------------------------------------------------------|
- 4 | Reserved | LoEj | Start |
- -----|-----------------------------------------------------------------------|
- 5 | Control |
- ==============================================================================
-
- The START STOP UNIT command (Table 8-33) requests that the target enable or
- disable the logical unit for media access operations.
-
- An immediate (Immed) bit of one indicates that status shall be returned as
- soon as the command descriptor block has been validated. An Immed bit of zero
- indicates that status shall be returned after the operation is completed.
-
- A load eject (LoEj) bit of zero requests that no action be taken regarding
- loading or ejecting the medium. A LoEj bit of one requests that the medium
- shall be be unloaded if the start bit is zero. A LoEj bit of one requests
- that the medium is to be loaded if the start bit is one.
-
- A start bit of one requests the logical unit be made ready for use. A start
- b.it of zero requests that the logical unit be stopped (media cannot be
- accessed by the initiator).
-
- Targets that contain cache memory shall implicitly perform a SYNCHRONIZE
- CACHE command for the entire medium prior to executing the STOP UNIT command.
-
-
- > Since you have not indicated anything that would suggest otherwise, it
- >is also possible that your drive is dead. Older Seagates in particular have
- >problems spinning up because (as I recall) the heads get stuck to the platters
- .
- >There is some kind of lubricant that is used internally, but as the drive gets
- >old the lubricant gets sticky.
-
- The 296N, 277R/N, and 251 are all built around the same HDA and can
- suffer from the same 251 stiction problem.
-
- >If this is the case, then drive replacement is
- >strongly recommended. When I ran across this, I was able to get the drive to
- >spin up by lightly hitting the drive with a screwdriver handle, but this shoul
- d
- >probably only be done when you are in a position to run a backup of some kind.
- >You should also make sure that there is not a spin-up command that needs to be
- >sent before you try any of this :-).
-
- On some disks, spin-up is controlled by a jumper.
-
- Eric :
-
- The disk driver should probably do a TEST UNIT READY (op code 0), and if that
- fails do a START STOP UNIT command with a ~60 second timeout and try again
- before failure.
-
- --
- Boycott AT&T for their absurd anti-BSDI lawsuit. | Drew Eckhardt
- Condemn Colorado for Amendment Two. | drew@cs.colorado.edu
- Use Linux, the fast, flexible, and free 386 unix |
-