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-
- JAZ-drive mini-HOWTO
- Bob Willmot, bwillmot@cnct.com
- v1.3, 05 August 1996
-
-
- This HOWTO covers the configuration and use of the Iomega Jaz drive
- under Linux and software tools available for the drive.
-
- 1. Introduction
-
- The Iomega Jaz drive is a removable media disk drive whose disks
- have a capacity of 1021 megabytes. It is currently available in internal
- and external SCSI configurations. Iomega plans to release an internal
- IDE version.
-
- This document describes how to use the Jaz drive with Linux. Since
- this is a SCSI device, it is important for you to read the Drew Eckhardt's
- SCSI HOWTO as well.
- http://sunsite.unc.edu/pub/Linux/docs/HOWTO/SCSI-HOWTO
-
- I'd like to thank the following people for their contributions and info
- they've provived.
-
- * Grant Gunther, grant@torque.net
- * Tom Poindexter, tpoindex@nyx.net
- * Todd Woods, woods@cs.uiowa.edu
-
- If you have any comments/suggestions/corrections please send them to:
- Bob Willmot, bwillmot@cnct.com
-
-
- 2. The Jaz disks
-
- The Jaz disks (cartridges) resemble a stack of three 3.5" floppy disks
- that hold 1GB of data.
-
- The drive has a motorized mechanism that can eject the disk via
- a pushbutton on the from of the drive or through software (see
- below on info about the jaztools Linux software)
-
-
- 2.1. The Jaz Jet host adapter
-
- Iomega markets a SCSI host adapter under the name Jaz Jet.
-
- Aparently there are currently two versions of this controller available,
- based on two difference SCSI chipsets.
-
- One is based on the Adaptec 7800 family of adapters, and is compatible
- with the 2930/2940 host adapters. Linux 2.0 supports this adapter with
- the aic7xxx driver. (this driver was introduced in the 1.3.? version of
- the kernel).
-
- The other adapter is based on the Advanced Systems chipset. At boot time
- the board gives a message like
- Jaz Jet PCI SCSI adapter Copyright Advanced Systems 1996
- Compile the kernel with the CONFIG_SCSI_ADVANSYS variable set.
-
-
- 3. Configuring a kernel for the Jaz drive
-
- To use the Jaz drive with Linux, you must have a kernel configured
- for you SCSI adapter.
-
- Info on building the kernel can be found in the /usr/src/linux/README
- file, or in /usr/src/linux/Documentation/ directory for the 2.x kernels.
-
- Also check out Brian Ward's Kernel-HOWTO
- http://sunsite.unc.edu/pub/Linux/docs/HOWTO/Kernel-HOWTO
-
-
- 4. Identifying the drive at boot time
-
- When your system boots it should display information about your adapter,
- and any disks that arre attaced to the drive.
-
- Boot messages will vary depending on your SCSI adapter and are logged
- to the /var/log/messages (or /var/adm/messages) file. You can also
- 'replay' these messages from the command prompt with the dmesg command.
-
- Here's the kernel booting output from a 2.0.10 kernel with an
- Adaptec 2940 controller:
-
- aic7xxx: BurstLen = 8 DWDs, Latency Timer = 64 PCLKS
- aic7xxx: AHA-2940 Ultra Rev B.
- aic7xxx: devconfig = 0x580.
- aic7xxx: Reading SEEPROM...done.
- aic7xxx: Extended translation enabled.
- aic7xxx: Using 16 SCB's after checking for SCB memory.
- AHA-2940 Ultra (PCI-bus):
- irq 11
- bus release time 40 bclks
- data fifo threshold 100%
- SCSI CHANNEL A:
- scsi id 7
- scsi selection timeout 256 ms
- scsi bus reset at power-on enabled
- scsi bus parity enabled
- scsi bus termination (low byte) enabled
- aic7xxx: Downloading sequencer code...done.
- aic7xxx: Resetting the SCSI bus...done.
- scsi0 : Adaptec AHA274x/284x/294x (EISA/VLB/PCI-Fast SCSI) 3.2/3.1/3.0
- scsi : 1 host.
- aic7xxx: Scanning channel A for devices.
- aic7xxx: Target 4, channel A, now synchronous at 10.0MHz, offset(0xf).
- Vendor: iomega Model: jaz 1GB Rev: G.60
- Type: Direct-Access ANSI SCSI revision: 02
- Detected scsi removable disk sda at scsi0, channel 0, id 4, lun 0
- scsi : detected 1 SCSI disk total.
- SCSI device sda: hdwr sector= 512 bytes. Sectors= 2091050 [1021 MB] [1.0 GB
- ]
- sda: Write Protect is off
-
-
- In the above log note the raw scsi device name (sda,sdb, etc).
- You'll need to use this to access the disk later.
-
- If these lines do not appear, then something is misconfigured in your
- hardware or in the kernel.
-
- If the scsi0: line does not appear, then you have not configured your
- host adapter and its driver correctly. Some drivers will give you a
- hint about what is wrong. If your drive is not detected, you
- probably have a cable problem. If a drive name is not assigned, you
- probably forgot to include SCSI disk support when you built the
- kernel.
-
- Check the README files in drivers/scsi and the SCSI HOWTO for other
- debugging hints.
-
- 4.2. Fdisk, mke2fs, mount, etc.
-
- Once you know the drive name for your Jaz drive, you are set. You can
- manipulate the drive with the normal Linux disk management commands,
- fdisk, mke2fs, mount etc.
-
- Refer to the manual pages for these programs.
-
-
- 4.2.1. An existing DOS formatted disk
-
- Disks factory formatted from Iomega are partitioned with a single
- partition (for some unknown reason they use the 4th partition).
-
- You can mount this disk (assuming your jaz disk is the raw SCSI device
- sda) with the commands
-
- mkdir /jaz
- mount -t msdos /dev/sda4 /jaz
-
- Or if you are using the 2.0 kernels and have compiled the kernel with
- support for the Win95 VFAT support you can mount it with
-
- mkdir /jaz
- mount -t vfat /dev/sda4 /jaz
-
- (this will allow you to read/write long filenames)
-
- Files from the disk will appear in /jaz. While the disk is
- mounted, you will not be able to eject it.
-
- To unmount the drive you can issue the command:
-
- umount /dev/sda4
-
- Once you've made the /jaz mount point - you don't need to do it again,
- (also make sure your not in the /jaz dir when you try to umount the
- drive)
-
-
- 4.2.2. Re-format as a native Linux disk
-
- If you want to erase a Jaz disk and make a Linux native file system on
- it. you should use fdisk on the entire disk:
-
- fdisk /dev/sda
-
- and delete any existing partitions (with the d command). Then create
- a new partition with the n command, make it primary partition number
- 1, use w to write the partition table to disk, and quit with q.
-
- Format the partition
-
- mke2fs /dev/sda1
-
- (The 1 is the number that you gave this partition in fdisk). Now you
- can mount the disk:
-
- mount -t ext2 /dev/sda1 /jaz
-
- (re-using that mount point we created before).
-
- 4.2.3. The Jaz Tools disk
-
- There is some extra work to be done if you want to use the disk that
- comes with the Jaz drive. As shipped, the software controlled write
- protection is enabled. Most people have unlocked the disk under DOS
- before ever trying to use it with Linux. Linux cannot access a locked
- disk, and it must be unlocked with Iomega's tools.
-
- 5. jaztools
-
- A native Linux program to support some of Iomega's special features
- (including software controlled ejection and write protection)
- is available at
-
- http://www.cnct.com/~bwillmot/jaztool/
-
- There should be a new version of jaztool available shortly that will
- contain a GUI interface and support drive scanning and automated
- mounting and unmounting of disks.
-
-
- 6. Frequently asked questions
-
-
- 6.1. The Jaz locks my system after it spins down ?
-
- People have reported problems with 1.2 (and early 1.3) kernels that
- when the Jaz disk spun down it would lock their system, or just
- produce a mess of SCSI error messages.
-
- I have not had any problems with the 2.0.x kernels and spindown of the
- Jaz. If you are having problems try the latest 2.0.x kernel available
- from http://sunsite.unc.edu/pub/Linux/kernel/v2.0/
-
-
- 6.2. Can I boot from the Jaz drive ?
-
- This depends on what you are using for a host adapter. If your host
- adapter has a BIOS ROM with code that can boot from target 5 or 6,
- then yes, you can boot from the Jaz drive.
-
- 6.3. Why does Iomega use partition number 4 ?
-
- I have no idea? Any clues?
-
-
- 6.4. How can I have the disk mounted at boot time ?
-
- All you need to do is to add a line to your /etc/fstab file. For
- instance, if you will always have a DOS disk in the drive when you
- boot, you could put
-
- /dev/sda4 /jaz msdos defaults 0 0
-
- in the fstab. Depending on your distribution, the initialization
- scripts might try to run fsck on partitions listed in your fstab. Be
- aware that this could cause problems if you forget to put the disk in
- the drive when you boot, or have the wrong disk there.
-
- 6.5. What happens if there is no disk inserted when I boot ?
-
- The kernel will try to read the partition table, but the operation
- will (eventually) time out.
-
- When you change disks, it is a good idea always to use fsck to
- check the partition structure on the new disk.
-
- The BIOS on some SCSI host adapters will attempt to read the partition
- table on your disk during the system boot. If you cannot disable this
- check, you may be forced always to boot with a disk in the drive.
-
-
- 7. Getting more current information
-
- The most up-to-date version of this mini-HOWTO can be found at:
-
- http://www.cnct.com/~bwillmot/jaztool/
-
- Iomega's web pages are at
-
- http://www.iomega.com/
-
-
-