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(?) ide-scsi emulation for IDE IOMEGA ZIP 250MB

From Dominik Szczerba

Answered By Matthias Posseldt, Ben Okopnik, John Karns, Mike Martin

Hello,

Do you have experience with ide-scsi emulation for IDE ZIP? For the last week I have searched the whole internet wide and broad and found no info on my very problem (only some similar ones), which is "unable to read partition table" and/or "READ CAPACITY failed" on my dev/sda during start-up (errors from dmesg and/or boot.msg, the disk was both in and out for testing during boot). I have my internal IDE ZIP drive 250 MB on my machine physically under /dev/hdb (internal ZIP 250MB), but I made it emulated under /dev/sda (because I had similar problem just using /dev/hdb, so I used ide-scsi after being suggested to do so). Apart from errors in boot.msg and dmesg, "fdisk -l" or fdisk /dev/sda => 'p' doesnt recognize the partition table of correctly formated (on other machines, external USB IOMEGA ZIP 250, running usb scsi emulation) ZIP disks with ext2 file system (I didnt try fat, I am not concerned). But I can mount the disk, but I am affraid to write to it because of obvious error messages.

(!) [John K.] Have you read the ZIP-Drive mini-HowTo? Is your drive simple IDE or the later ATAPI model? From that document:
IDE:
The good news about this drive: no kernel modules or modifications are needed to support it. It looks to the kernel like an IDE hard drive. It worked for me with no effort with kernel 2.0.31 and 2.0.32.
The bad news about this drive: because it doesn't use ATAPI, you can't use the SCSI-to-ATAPI translation, which means you can't use mtools to write-protect disks (or to eject them, for that matter).
ATAPI:
I use an ATAPI Zip drive and it works with both 2.0.32 and 2.0.33 kernels. I've used it under both RH 5.0 and OpenLinux 1.2 (my current used distribution). To get it to work under OpenLinux, I just enabled ATAPI floppy support in the kernel. OpenLinux does not have this support compiled in by default.
No other drivers are needed. It will mount as an extended partition on partition 4. I.E, mine mounts on HDB4. I mount it under /mnt/zip as noauto, although I don't suppose there would be any real problem with automounting. I just wonder about ejecting disks. I always dismount the drive before ejecting a cartridge.
There are more detailed instructions for the ATAPI install in the Linux Gazette May 1998 issue. See the 2 cent tip section.
http://www.linuxgazette.com/issue28/lg_tips28.html#atapi
(!) [Matthias] Have you inserted the ide-floppy module or is IDE Floppy support compiled into your kernel. Only then you can use the ZIP drive like a removable hard drive.
so you do: "modprobe ide-floppy && modprobe ide-scsi" and carefully watch the kernel messages. If it doesn't help, please post the part of your kernel boot messages concerning the detection of the ZIP drive.

(?) To make it yet more complex: if I now format a ZIP disk on MY scsi-emulated IDE ZIP drive then I dont have ANY problems on MY machine (format/partition table is correctly recognized) but on ALL the other machines the disk is not recognized at all (not even mounting is possible).

(!) [Matthias] How did you format the disks? With mke2fs /dev/hdb?

(?) please help me solve this puzzle,

regards, Dominik

(!) [Matthias] Perhaps this helps a bit.

(?) Hello wizards,

(?) Have you inserted the ide-floppy module or is IDE Floppy support compiled into your kernel. Only then you can use the ZIP drive like a removable hard drive.

ide-floppy 0.99 is reported in both machines at startup, and in both machines the module is NOT loaded.

(!) [Ben] I can't offer much help on the overall topic, not having any experience with ZIP, but one thing seems clear from the above: the "ide-floppy" functionality is compiled into your kernel.

(?) In both machines (ZIP IDE and ZIP USB) I CAN format/copy from/to, but errors are reported using the disk on ANOTHER computer. I didnt try to configure the kernel as I thought "I CAN use the drive so the drivers are there". Anyway, I am not going to recompile the kernel, because it doesnt solve the problem of easy compatibility of ZIP drives. I dont want to have this problem when going to yet another computer...

so you do: "modprobe ide-floppy && modprobe ide-scsi" and carefully watch the kernel messages.

ide-floppy module is just not there, so it is not modprobing... (module not found or something)

(!) [Ben] "Or something" is not a useful error report; however, if it's compiled in, you won't have a module - so this is another indication of the above. Presumably, the error will look something like this:
modprobe: Can't locate module ide-floppy

(?) Is your drive simple IDE or the later ATAPI model?

(!) It is being reported as IDE ATAPI (in BIOS and during startup) so I really dont know...

(!) [Ben] Yep, that would make it an IDE ATAPI.

(?) And forget about help from IOMEGA...

...............

In the HOWTO:

I use an ATAPI Zip drive and it works with both 2.0.32 and 2.0.33 kernels. I've used it under both RH 5.0 and OpenLinux 1.2 (my current used distribution). To get it to work under OpenLinux, I just enabled ATAPI floppy support in the kernel. OpenLinux does not have this support compiled in by default.

...............

1) I have kernel 2.4.18-4GB installed (default from SuSE 8), so I thought all latest technology is there, no?

(!) [Ben] I'm not sure what you mean by "the latest technology", but it should have a reasonably new version of "ide-floppy" support - either compiled in (as it seems to be in your case) or as a loadable module.
(!) [Matthias] Yes, SuSE's kernel should suffice. You can use the drive, and ide-floppy support is built into the kernel.

(?) 2) Anyway, I CAN use the drive, so the drivers must be there. The problem is compatibility. Am I wrong?

(!) [Ben] I'm afraid that I missed the first part of this discussion, however - when you say that the errors are reported on "another" computer, is "ide-floppy" loaded on _that machine (either via being compiled in or modprobing "ide-floppy")? The two machines that you report as being able to format, copy, etc. are obviously getting it to work; the third one isn't. So, the third machine has some kind of a problem - perhaps the module does not get loaded on it?

(?) I have removed the scsi-emulation on my home PC. It is still the same.

(!) [mike] do an lsmod and check for imm and ppa modules
(!) [Ben] Both of those are SCSI-related modules; I think that Dominic has already determined that SCSI is irrelevant to what he's doing (unloading SCSI emulation has no effect on the process.) As well, it's a good idea to explain to people _why they should do things that you recommend: if your exact suggestions don't pan out, they would be able to explore an avenue that they may not have been aware of.
(!) [Heather] But they would have been the correct modules if it was an older, parallel based ZIP drive. As noted above, however, if they were built-ins, then you wouldn't have them available as modules, but they would have been likely to "just work".

(?) Self-made disks are 100% OK, but not accesible elsewhere (cannot mount nor read).

(!) [Ben] "Elsewhere" meaning other machines besides these three? Like, on a ZIP drive under Wind*ws, etc.?
(!) [John K.] I think he means that Zip carts init'ed on the problem machine can't be read by other Zip drvs. I would not rule out an alignment compability issue here.

(?) And if I use elsewhere-formatted disks on my PC I get wrong partition table message from fdisk (but I can mount it and read it!)

(!) [Ben] <shrug> I'd say, ignore "fdisk". It's not the smartest utility in the world in the first place, and using it on anything except a plain HD is asking for trouble.
(!) [John K.] While I wouldn't recommend using fdisk to set up partitions on the Zip carts, I've used it with good results to show the status (fdisk -l).
(!) [Matthias] Yes, ZIP disks don't have a standard partition table. Same with LS-120 disks. I read about LS-120 & Linux and it was said you should not low-level format the disk as it can render it unusable.
The data partition on the ZIP disk is number 4, so you've to 'mount -t auto /dev/hdb4 /mnt/zip'.
So, one tip is to format the disk using IOMEGA tools under Windows (arghh). A different one is using the tools provided at http://www.iomega.com/software/linuxtools.html
There you have formatting tools, tools to write protect your disks and information utilities. Works with ATAPI ZIP 100 & 250 and SCSI counterparts.
(!) [mike] try mounting /dev/sda4 /mnt/zip zip drives historically have the data in partition 4
This should definitely solve the problem if when you format the drive properly you get no problems

(?) do you still have some ideas?

Is it possible just to have ZIP compatible like every CD device without experimenting (!!!) with kernel stuff? If not I take the battle as lost and stop using ZIP drives... Warn others...

best regards, Dominik

(!) [Ben] There's lots of folks out there using ZIP drives with Linux. I think that sounding the fire alarms and calling the New York Times would be premature at best.
(!) [John K.] My use of Zip drvs has been confined to the SCSI (Linux & MS) and parport models (MS only). I've never had any real problems, (other than very slow with the parport version).

Unfortunately, these seem to be all reasonable things, but the real problem was something more akin to floppy alignment problems. -- Heather

(?) So, one tip is to format the disk using IOMEGA tools under Windows (arghh). A different one is using the tools provided at http://www.iomega.com/software/linuxtools.html

great, but... unfortunately it just...simply... doesnt work! It doesnt do what's written in help file.
I convinced myself how low quality iomega is. Never ever anything to do with them.
And my messages to iomega were just left without any response.
I checked with FAT file systems. The same. It works 100% OK... but only on the machine it was formated on. I am sick with this.
Thank you guys for feedback, but I give up and throw away the stupid drive.
No, no need to alarm New York Times, Ben, but a word of loud warning on incopatibility of ZIP disks formatted on different machines will prevent others from wasting their money.
What I experienced just prooves how low quality service is offered by iomega.
thanks and bye Domi


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