Instructions for dirac's Jaz drive

Dirac is running Solaris 2.5 and has a Jaz drive on SCSI ID 5. Its mount point in the directory structure is /jaz and if exported can be seen from any machine on the Scripps network as /nfs/dirac/jaz

The original installation of the drive, as well as some of the following information was originally obtained from Iomega's Technical support document #2019.

Here are my instructions for doing essential things with the drive.

Contents

Formatting a new disk

  1. Make sure the disk doesn't have someone's data on it!

  2. Become root on dirac.

  3. Type "format". This gives you a list of the disks attached to dirac.

  4. From here on, BE CAREFUL!! The wrong mistake can blow away one of dirac's disks. Just follow these directions as you go and you will be fine.

  5. Enter the number of the disk entry that looks like:
    c0t5d0 <drive type unknown>.
    and press <return>.

    If you get a line that looks like:
    c0t5d0 <Jaz 1GB cyl 1018 alt 2 hd 64 sec 32>
    Stop! The disk is already formatted. Mount it and see what it contains.

  6. Now define the drive type as "Jaz 1GB" by selecting it from the "AVAILABLE DRIVE TYPES" menu.

  7. Enter "partition" to put you into "partition" mode

  8. Enter "print" to print the current partition table. You should see a line that looks like:
    2 backup wu 0 - 1017 1018.00MB (1018/0/0) 2084864
    This means the entire disk is contained in the third partition, /dev/rsd5c

  9. Enter "label" to write this label and partition map to disk, and confirm when prompted.

  10. Keep entering "q" until you have exited the format program completely.

  11. Now, to make a filesystem you type:
    newfs -o space -m 2 /dev/rsd5c
    the -o space -m 2 flags reserves only 2% of the filesystem for root vs. the default 10%.

Mounting/Unmounting a Jaz disk

Before you can eject a disk, you will need to unmount it. As root on dirac, use the command:

umount /jaz

This will fail if there are any processes which are using this device, i.e. if you left a shell whose current working directory is /jaz/mystuff. Beware of shells on top of shells, like if you were in /jaz/mystuff and then did su to become root to umount the disk. The original shell is still running and you won't be able to umount the drive until you change that shell's working directory.

Once your disk is in the drive, you can do:

mount /jaz

to mount your disk under the directory /jaz.

Exporting a Jaz disk

If you need to get to your data directly from another workstation, you can export the disk after it is mounted with the command (executed as root on dirac):

share /jaz

This will allow the disk to be nfs automounted from any Scripps machine when the directory /nfs/dirac/jaz is accessed. There are a couple weird things about this. If you have stale mount points from a different Jaz disk than the one that is in the drive, then the automount won't work and you will just be looking at empty directories. Paul has experienced this from euler, and I don't know how to fix it.

Also, if you leave processes running on other machines which access the drive via an nfs mount, nobody can unmount the disk to use the drive, so if you export the drive, please remember to:

unshare /jaz

when you are finished to prevent this annoyance.

Comments? Email:
jsmith@scripps.edu

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