how many disks do I have? Post: 9714

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Top Forums UNIX for Dummies Questions & Answers how many disks do I have? Post 9714 by Perderabo on Thursday 1st of November 2001 02:20:36 PM

11-01-2001

Administrator Emeritus

"format" will show all physical disks with sun. "prtconf" is also useful on suns. And "ioscan" or "sam" will do it on hp.

I'm gonna take a crack at describing controllers and targets...

Every disk and tape that you have will be connected to the computer by a cable. Data will go back and forth through that cable. The cable connects to a card in the computer. That card is the controller. Each card gets a number. So that is the controller number that people are talking about.

If you trace the cable from the card to the disk drive, you may find another cable the goes to a 2nd disk drive. Each disk drive will have two places to plug in a cable. The last disk drive should have a terminator instead of a cable on the 2nd connector. The i/o card in the computer and all the drives attached to it until that terminator is a "chain". Each drive on a chain will have an address set in some switches or a dial. And each drive on the chain better have a unique address. This address is that target number. So the disk with the target set to 2 on the first i/o card (controller 0) will be c0t2d0.

That last number will be 0 unless you have a disk array rather than a disk drive.

You can't just count the special files in /dev/dsk. If you unhook a disk drive and throw it away, the special files won't go away with most versions of unix. You can always use mknod to create a new special file. But if you do, a disk drive will not magically appear.

Perderabo

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LEARN ABOUT OSF1

fddisk

fddisk(8)						      System Manager's Manual							 fddisk(8)

NAME

       fddisk - FDI disk maintenance utility

SYNOPSIS

       /sbin/fddisk options special

OPTIONS

       Unless  this  option  is specified, an attempt to format or to install a file system fails in two cases.  The first failure occurs when the
       device has been opened since the media was inserted.  The second failure occurs if the device is currently opened by another process.  For-
       mats  the  media  to the density appropriate for that media.  Copies a hex dump of sector number PSN to stdout.	Uses the interleave factor
       nnn for formatting.  If specified, ccc indicates an additional intercylinder interleave.  Copies a packed-C hex dump of the entire disk	to
       stdout.	 Specifies silent mode.  This option blocks informational messages from appearing on stderr.  Reads the entire media.  The command
       fails if the utility finds a bad sector.  Waits for media to be inserted into the drive if none is present.  Waits  for	new  media  to	be
       inserted  into the drive if none is present or if the current media has been opened since it was last inserted.	Reads the disk and reports
       on the format of the disk.

OPERANDS

       Specifies an unmounted, raw device pathname.  This device must be an FDI interface (fd).

DESCRIPTION

       The fddisk utility, an FDI (integrated Floppy Disk Interface) disk maintenance program, can format a floppy disk, scan a  floppy  disk  for
       bad  blocks,  and  read	and  write selected blocks.  It can be used in shell scripts for checking the status of floppy disks.  Such status
       checks include checking for or waiting for the presence of media, and checking for or waiting for the user to change the media.

RESTRICTIONS

       The fddisk utility has the following restrictions: You must have read/write access to the device.  The device must  not	be  mounted.   The
       program can only be used with a 3.5-inch floppy disk in the RX26 drive.	In some cases, it might not be possible to format a floppy disk at
       a higher density than it is already formatted.  If this situation occurs, the floppy disk must be bulk erased before it can be  reformatted
       at a higher density.

EXAMPLES

       This  example formats a floppy disk in drive zero: # /sbin/fddisk -fmt /dev/rdisk/floppy0a This example formats a floppy disk in drive zero
       when the disk has been read or written since it was inserted into the drive: # /sbin/fddisk -fmt -f /dev/rdisk/floppy0a

SEE ALSO

       Commands: mount(8), restore(8), uerf(8)

       Files: fd(7)

																	 fddisk(8)