ftape-HOWTO
Kai Harrekilde-Petersen, <khp@pip.dknet.dk>
v1.3, February 5th, 1995 for ftape-2.02
This HOWTO discuss the essentials of the do's and dont's for the ftape
driver under Linux. The ftape driver interfaces to QIC-40, QIC-80,
QIC-3010 and QIC-3020 compatible drives only. The QIC-3010 and
QIC-3020 standards are also known as `QIC-WIDE'. These drives con-
nects via the floppy disk controller (FDC). It does not cover SCSI or
QIC-02 tape drives. DAT tape drives usually (always?) connect to a
SCSI controller. This is but one of the Linux HOWTO documents. You
can get the HOWTO's from sunsite.unc.edu:/pub/Linux/doc/HOWTO (this is
the ``official'' place) or via the web from the Linux Documentation
home page (http://sunsite.unc.edu/mdw/linux.hmtl). You cannot rely on
the HOWTO's being posted to comp.os.linux.announce, as some newsfeeds
have complained about their size.
1. Legalese
This is the `Frequently Asked Questions' (FAQ) / HOWTO document for
the ftape driver (ftape-HOWTO), Copyright (C) 1993, 1994, 1995 Kai
Harrekilde-Petersen.
Copyright statement:
You may distribute this document freely as a whole in any form and
free of charge. You may distribute parts of this document, provided
this copyright message is included and you include a message stating
that it is not the full HOWTO document and a pointer to where the full
document can be obtained. Specifically, it may be included in
commercial distributions, without my prior consent. However, I would
like to be informed of such usage.
You may translate this HOWTO into any language, whatsoever, provided
that you leave this copyright statement and the disclaimer intact, and
that you append a notice stating who translated the document.
DISCLAIMER:
While I have tried to include the most correct and up-to-date
information available to me, I cannot guarantee that usage of the
information in this document does not result in loss of data. I
provide NO WARRANTY about the information in the HOWTO and I cannot be
made liable for any consequences for any damage resulting from using
information in this HOWTO.
2. News flash
This isn't exactly news, but anyway: the page numbers in the Table of
Contents (which appear at least in the LaTeX'ed versions), are off-by
one (ie: things appear one page later than what the table of contents
thinks. I can't help it).
version 1.3 (Feb 5, 1995)
o New section on how to create an emergency boot disk added
(written by Claus Tondering, <ct@login.dknet.dk>).
version 1.2 (Feb 2, 1995)
o IOmega Tape Accellerator II controller added.
version 1.12 (Jan 16, 1995)
o Updated to ftape-2.02.
o 2.01a patch removed again :-)
version 1.11 (Jan 15, 1995)
o Updated to ftape-2.01a and included the 2.01a patch.
version 1.1 (Jan 11, 1995)
o Corrected a typo in Antti's email address.
o Updated to ftape-2.01
o List of known drives expanded
o Added more about the QIC-3010/3020 (QIC-WIDE) support
3. The preliminaries
Note that I (the howto-maintainer) no longer use ftape myself, so I
cannot give much up-to-date advice on e.g. compiling ftape. If you
have a problem, try posting on comp.os.linux.help, or to the TAPE
channel (see ``Following the ftape development'' below). You should
try to post a summary of your problems and its solution(s), after
you've got it working, even if you only got it partially working.
Please also send me (<khp@pip.dknet.dk>) a copy of your solution so
that I can add it to the HOWTO.
I read my mail daily, I try to respond to everyone, but I cannot
guarantee that I will respond immediately. Also, I seldomly read the
newsgroups (comp.os.linux.help et al), as my Internet access is
through a modem line and I have to read news On-line 8-(.
If you recieve this as part of a printed distribution or on a CD-ROM,
please check out the Linux Documentation home page
(http://sunsite.unc.edu/mdw/linux.hmtl) or ftp to sunsite.unc.edu:
/pub/Linux/doc/HOWTO to see if there exists a more recent version.
This could potentially save you a lot troubles.
4. Getting and installing ftape
I will eventually include an installation guide in this section.
You'll have to do without it, for the moment being.
4.1. What is ftape
ftape is a driver program that controls various low-cost tape drives
that connect to the floppy controller.
ftape is not a backup program as such; it's a device driver, which
allows you to use the tape drive (just like the SoundBlaster 16 driver
let you use your sound card) through the device file /dev/[n]rft[0-3].
ftape is written by Bas Laarhoven <bas@vimec.nl>, with ``a little help
from his friends'' to sort out the ECC (Error Correcting Code) stuff.
ftape is copyrighted by Bas under the GNU General Public License,
which basically says: ``go ahead and share this with the world, just
don't disallow other people from copying it further''.
ftape is currently beta testing, and has been that for some time now.
Although it seems reasonable stable and reliable, it still changes
relatively often. These changes are either because some bug as been
unearthed, or (what has happen a few times recently) because the
modules interface in the Linux kernel has changed.
ftape supports drives that conform to the QIC-117 and one of the
QIC-80, QIC-40, QIC-3010, and QIC-3020 standards. ftape does not
support QIC-02 tape drives or drives that connect via a SCSI
interface, e.g. a DAT drive. SCSI drives are accessed as
/dev/[n]st[0-7] and are supported by the kernel through the SCSI
drivers. If you look for help on SCSI tape drives, you should read
the SCSI-howto. See section ``Supported drives'' and ``Un-supported
drives'' for a list of supported and unsupported drives.
4.2. How fast is ftape?
You can achieve quite respectable backup and restore speeds with
ftape: I have a Colorado DJ-20 and an Adaptec 1542CF controller, and
have measured a 4.25Mbyte/min sustained data transfer rate (no
compression) across a 70Mbyte tar archive, while comparing the archive
on the tape with data on my IDE disk. The speed of ftape is mostly
dependent on the data transfer rate of your FDC: The AHA1542CF has a
``post-1991 82077'' FDC, and it will push 1Mbit/sec at the tape drive.
If you have an FDC which can only deliver 500Kbit/sec data rates, you
will see half the transfer rate (well, roughly).
4.3. The newest version of ftape - and where to get it
The newest version of the ftape driver is ftape-2.02, which consists
of ftape-2.02.tar.gz and ftape-lsm. ftape can be fetched from the
following sites:
sunsite.unc.edu [152.2.22.81]: /pub/Linux/kernel/tapes/
You should get the files: ftape-2.02.tar.gz, and ftape-lsm. The
.tar.gz file is the ftape driver proper, while the lsm file is a
Linux Software Map (LSM) file for the LSM project.
Newer kernels (from 1.1.85 and on), have improved support for loadable
modules (by Bjorn Ekwall and Jacques Gelinas), which (if possible)
allows you to insert modules compiled for an `old' kernel into a `new'
kernel. To compile the kernel with this improved module support, you
need the modules-1.1.87.tar.gz file. It can be found on
tsx-11.mit.edu and sunsite.unc.edu: (on sunsite, it's still in
pub/Linux/Incoming). You must compile and install it before you
compile the kernel.
WARNING: ftape-1.14 does not work. You must upgrade to at least
ftape-1.14a.
Note that the version number of ftape jumped from 1.14d directly to
2.00.
4.3.1. Patches to ftape-2.02
Around 1.1.85 of the Linux kernel, <linux/sched.h> stopped including
the <linux/mm.h> file, which ftape needs. Therefore, you must add it
to ftape.h by hand.
--- ftape.h.orig Mon Jan 23 22:44:22 1995
+++ ftape.h Mon Jan 23 22:05:48 1995
@@ -31,6 +31,7 @@
*/
#include <linux/sched.h>
+#include <linux/mm.h>
#include "tracing.h"
4.3.2. Problems with kernel version 1.1.5x
During patchlevel 50 to 60, the floppy driver got changed a few times.
A some point, the floppy driver forgot to release the interrupt line
(IRQ6). This would result in that you could not use ftape and a
floppy drive at the same time. It also resulted in the if you tried
to make a ``rescue disk'' (a very sensible thing), where you would
boot from floppy and then restore from your backup tape, you
experience that when you used ftape, it would say `unable to grab IRQ6
for ftape driver'. No fun. The solution is to upgrade the kernel
(v1.1.59 will work).
4.4. If you have ftape-1.14a, or earlier
There have been fixed some serious bugs in the driver and you should
really consider to upgrade to at least 1.14d.
4.5. ftape driver Following the development of the
If you want to follow the development of the ftape driver, you should
consider subscribing to the TAPE channel on Linux-activists. To
subscribe, you send a mail to <linux-activists-
request@niksula.hut.fi>, with the first line (or as a part of the
header) saying `X-Mn-Admin: join TAPE'. If you send an empty mail you
are sent a HOWTO mail.
To submit a real mail to the mailing lists, send a mail to <linux-
activists@niksula.hut.fi>, and remember that the first line (or a
header line) should read `X-Mn-Key: TAPE'.
To get off the TAPE channel (:-(), send a mail to <linux-activists-
request@niksula.hut.fi> with the line `X-Mn-Admin: leave TAPE'
There is also a TAPE mailing list on vger.rutgers.edu. To subscribe to
it, send a mail saying `subscribe linux-tape' to
majordomo@vger.rutgers.edu. When you subscribe, you will be sent a
greeting mail, which will tell you how to submit real mails and how to
get off the list again.
4.6. Compiling and installing the ftape driver
There is included an installation guide (the file Install-guide) in
the ftape distribution; please read that.
4.7. Where to get the kernel sources
You can get the kernel sources from the same place as you got the
ftape sources. The sources are kept at the following sites (and many
mirror-sites)
tsx-11.mit.edu [18.172.1.2]: /pub/linux/sources/system/
sunsite.unc.edu [152.2.22.81]: /pub/Linux/kernel/
ftp.funet.fi [128.214.248.6]: /pub/OS/Linux/PEOPLE/Linus
You will find a number of subdirectories, including two named v1.0 and
v1.1. These contain (you guessed it!) v1.0 and v1.1 of the kernel. I
suggest that you get version 1.1.<something>.
4.8. Can I format my tapes under Linux?
No! Honestly, noone is working on it: If you want to work on it, drop
Bas a line. You'll have to use MessyDOS (arghhh!) instead or buy
preformatted tapes. However, some of the preformatted tapes are not
checked for bad sectors!. If the ftape driver encounters a tape with
no bad blocks, it will issue a warning. If ftape barfs at your
preformatted tapes, try out your DOS software. If both the DOS
software and ftape barfs on your tapes, a reformat will very probably
cure the problem.
Note that to be able to use your newly formatted tapes under ftape,
you must erase the tape first:
mt -f /dev/nftape erase
4.9. Which formatting programs can I use under DOS?
These are known to work:
o Colorado Memory System's software (tape.exe)
o Conner Backup Basics v1.1 and all Windows versions
o Norton Backup
o QICstream version 2
o Tallgrass FileSecure v1.52
These programs are known to be more or less buggy:
o Conner Backup Basics 1.0
o Colorado Windows tape program
o CP Backup (wastes tape space, but is OK apart from that)
In fact, most software under DOS should work. The Conner Backup
Basics v1.0 has a parameter off-by-one (someone could not read the
QIC-80 specs right!), which is corrected in version 1.1. However,
ftape detects this, and will work around it. Dennis T. Flaherty
(<dennisf@denix.elk.miles.com>) report that Conner C250MQ owners can
obtain the new v1.1, by calling Conner at 1-800-4Conner (in the US)
and ask for an upgrade (for a nominal fee for the floppy). The
Windows versions should work fine. Some versions of Colorado's tape
program for windows, has an off-by-one error in the number of
segments. ftape also detect and work around that bug.
Central Point Backup can be used, but it wastes precious tape space
when it encounters a bad spot on the tape.
NOTE: If you are running a formatting software under DOS, which is not
mentioned here, please mail the relevant info to me
(<khp@pip.dknet.dk>), so I can update the HOWTO.
4.10. Mixing ftape and floppies
Since both the floppy driver and ftape needs the FDC (and IRQ6), they
cannot run concurrently. Thus, if you have mounted a floppy and then
try to access the tape drive, ftape will complain that it cannot grab
IRQ6 and then die. This is especially a problem when designing a
emergency disk for use with ftape. This solution is to either load
the boot/root disk into a ramdisk and then unmount the floppy, or have
two FDC's.
5. (Un)supported hardware
5.1. Supported tape drives
All drives that are both QIC-117 compatible and either QIC-40 or
QIC-80 compatible should work. There are also experimental support of
QIC-3010 and QIC-3020 drives (QIC-3010/302 can use 8mm tapes. This is
sometimes refered to as `QIC-WIDE'). Currently, the list of drives
that are known to work with ftape is:
o Alloy Retriever 250
o Archive 5580i / XL9250i
o Colorado DJ-10 / DJ-20 (aka: Jumbo 120 / Jumbo 250)
o Conner C250MQ
o Conner TSM420R (partly)
o Escom / Archive (Hornet) 31250Q
o Insight 80Mb
o Iomega 250
o Mountain FS8000
o Summit SE 150 / SE 250
o Tallgrass FS300 (needs a tiny hack to work with AHA1542B)
o Memorex tape drive backup system
o Wangtek 3080F
You can always check out the newest list of drives that are recognised
by ftape, by looking in the file vendors.h in the ftape distribution.
Although I do not want to endorse one drive type over another, I want
to mention that the Colorado DJ-20 drive is rather noisy, when
compared to, say, a Conner C250MQ drive ('tis said that the Colorado
is 5-10 times as noisy as the Conner drive. I can't tell for sure, but
I have a Colorado, and it is quite noisy).
If you have a Tallgrass FS300 and an AHA1542B, you need to increase
the bus-on / bus-off time of the 1542B. Antti Virjo
(<klanvi@uta.fi>), says that changing CMD_BUSON_TIME to 4 and
CMD_BUSOFF_CMD to 12 in linux/drivers/scsi/aha1542.c will do the
trick.
One user has reported that ftape works (partially) the with Conner
TSM420R drive, which supports both QIC-80 (normal) and `QIC-WIDE'
tapes. As of right now, ftape provides only experimental support the
QIC-WIDE tapes, and you should consider it it sheer luck that the
TSM420R works at all with ftape (or any other QIC-WIDE drive).
Hopefully, the TSM420R drive, and other QIC-WIDE drives, will be
supported fully soon. If you have a drive that can use QIC-WIDE
tapes, are interested in getting it to work with ftape, and not afraid
of being ALPHA tester, drop Bas <bas@vimec.nl> a mail, stating which
drive you have.
NOTE: If you have a drive that works fine, but it is not listed here,
please send a mail to the HOWTO maintainer (<khp@pip.dknet.dk>).
5.2. Supported special controllers
These dedicated high-speed tape controllers are supported by ftape:
o Colorado FC-10
o Mountain MACH-2
o IOmega Tape Accelerator II
Support for the FC-10 controller has been merged into the ftape driver
in version 1.12. See the RELEASE-NOTES and the Makefile files in the
ftape distribution.
The support for the MACH-2 controller was added in ftape-1.14d.
To use the IOmega Tape Accelerator II, use -DMACH2, and set the right
settings for I/O base, IRQ and DMA. This works (by the empirical
testing of Scott Bailey <sbailey@xcc.mc.xerox.com>), with at least
ftape-2.02.
Anti-Colorado message:
As of lately, Colorado has proved themselves totally unwilling to help
with FC-10 and FC-20 support. This is sad, and can only force me to
say: Don't buy a Colorado high-speed controller, or even a Colorado
tape drive. Why support a manufacturer, who does not want to support
his own product?
5.3. Un-supported tape drives
o All drives that connect to the parallel port (eg: Colorado Trakker)
o High-Speed controller's. (eg: Colorado TC-15 & FC-20)
o Irwin AX250L / Accutrak 250. (not a QIC-80 drive)
o IBM Internal Tape Backup Unit (identical to the Irwin AX250L drive)
o COREtape light
Generally, ALL drives that connect to the parallel port are NOT
supported. This is because these drives uses (different) proprietary
interfaces, that are very much different from the QIC-117 standard.
The Colorado TC-15 controller (and it's like) are not supported
directly by the ftape driver. The only `special' controllers that can
be used with ftape is the Colorado FC-10 and the Mountain MACH-2 (see
above).
The Irwin AX250L (and the IBM Internal Tape Backup Unit) does not work
the ftape. This is because they only support QIC-117, but not the
QIC-80 standard (they use Irwin's proprietary servoe (Rhomat) format).
I know nothing about the Rhomat format, nor where to get any info on
it. Sorry.
The COREtape light, does not accept the initialisation commands, we're
feeding it. This pretty much leaves the drive unusable.
5.4. Using an external tape drive with ftape
If you have a floppy controller which has a female DB37 connector on
the bracket (and some means of delivering power to the drive), you can
use it with ftape. OK, that sentence was not very obvious. Let's try
it this way: Some FDC's (the very ancient one's), have a DB37
connector on the bracket, for connecting to external floppy drives.
If you make a suitable cable (from a quick glance on an FDC that I've
got lying around, it seems to be a straight 1-to-1 cable. However,
your milage may vary) from the DB37 connector (on the FDC) and to your
external tape drive, you can get ftape to control your tape drive.
This is because that from a program's view there is no difference
between the internal and the external connectors. So, from ftape's
point of view, they are identical.
5.5. ftape Getting PCI motherboards to work with
Unfortunately, some PCI motherboards cause problems when running
ftape. Some people have experienced that ftape would not run in a PCI
based box, but ran flawlessly in a normal ISA based 386DX machine. To
quote from the RELEASE-NOTES file in the ftape distribution:
More PCI news:
--------------
There have been more reports about PCI problems, some of them
were solved by upgrading the (flash) BIOS.
Other rumours are that it has to do with the FDC being on the
PCI bus, but that is not the case with the Intel Premiere boards.
Here is a list of systems and the BIOS versions known to work:
board: bios revision:
Intel Premiere PCI (Revenge) 1.00.09.AF2
Intel Premiere PCI II (Plato) 1.00.08.AX1 (disable GAT in BIOS!)
1.00.10.AX1
To see if you're having the GAT problem, try making a backup
under DOS. If it's very slow and often repositions you're
probably having this problem.
PCI news:
---------
There have been some problem reports from people using PCI-bus based
systems getting overrun errors.
I wasn't able to reproduce these until I ran ftape on a Intel Plato
(Premiere PCI II) motherboard with bios version 1.00.08AX1.
It turned out that if GAT (Guaranteed Access Timing) is enabled (?)
ftape gets a lot of overrun errors.
The problem disappears when disabling GAT in the bios.
Note that Intel removed this setting (permanently disabled) from the
1.00.10AX1 bios !
It looks like that if GAT is enabled there are often large periods
(greater than 120 us !??) on the ISA bus that the DMA controller cannot
service the floppy disk controller.
I cannot imagine this being acceptable in a decent PCI implementation.
Maybe this is a `feature' of the chipset. I can only speculate why
Intel choose to remove the option from the latest Bios...
The lesson of this all is that there may be other motherboard
implementations having the same of similar problems.
If you experience a lot of overrun errors during a backup to tape,
see if there is some setting in the Bios that may influence the
bus timing.
6. Backing up and restoring data
This section describes some simple uses of tar and mt.
6.1. Writing an archive to a tape
You can use `tar', `dd', `cpio', and `afio'. You will need to use `mt'
to get the full potential of your tapes and the ftape driver. For a
start I'd recommend using `tar', as it can archive lots of directories
and let you pick out seperate files from an archive. I have been told
that cpio creates smaller archives and is more flexible than tar, but
I haven't tried it myself. `afio' creates backups where each file is
compressed individually and then concatenated. This will allow you to
access the files ``after'' the point of the error. If you use gzipped
tar files, all data after the point of the error is lost! (to me, this
is a pretty good reason for NOT using compression on backups).
To make a backup of your kernel source tree using tar, do this
(assuming you have the sources in /usr/src/linux):
cd /usr/src
tar cf /dev/ftape linux
This will not compress the files, but gives you a smoother tape run.
If you want the compression (and you've got tar 1.11.2), you just
include the -z flag(*), eg: `tar czf /dev/ftape linux'
For further instructions on how to use tar, dd and mt look at the man
pages and the texinfo files that comes with the respective
distributions.
(*) tar assumes that the first argument is options, so the `-' is not
necessary, i.e. these two commands are the same: `tar xzf /dev/ftape'
and `tar -xzf /dev/ftape'
6.2. Restoring an archive
OK, let us restore the backup of the kernel source you made in section
``Writing an archive to a tape'' above. To do this you simply say
tar xf /dev/ftape
If you used compression, you will have to say
tar xzf /dev/ftape
When you use compression, gzip will complain about trailing garbage
after the very end of the archive (and this will lead to a `broken
pipe' message). This can be safely ignored.
For the other utilities, please read the man page.
6.3. Testing the archive
tar has an option (-d) for detecting differences between two archives.
To test your backup of the kernel source say
tar df /dev/ftape
If you do not have the man page for tar, you are not lost (yet); tar
has a builtin option list: try `tar --help 2>&1 | more'
6.4. Putting more than one tar file on a tape
To put more than one tar file on a tape you must have the mt utility.
You will probably have it already, if you got one of the mainline
distributions, e.g. Slackware or Debian.
tar generates a single Tape ARchive (that's why it is called `tar')
and knows nothing about multiple files or positioning of a tape, it
just reads or writes from/to a device. mt knows everyting about moving
the tape back and forth, but nothing about reading the data off the
tape. As you might have guessed, tar and mt in conjunction, does the
trick.
By using the nrft[0-3] (nftape) device, you can use `mt' to position
the tape the correct place (`mt -f /dev/nftape fsf 2' means step over
two ``file marks'', i.e. tar files) and then use tar to read or write
the relevant data.
6.5. Appending files to an archive
``Is there a way to extend an archive -- put a file on the tape, then
later, add more to the tape?''
No. The tar documentation will tell you to use `tar -Ar', but it does
not work. This is a limitation of the current ftape driver.
6.6. Mount/unmounting tapes
Since a tape does not have a ``filesystem'' on it, you do not mount /
unmount the tape. To backup, you just insert the tape and run your
`tar' command (or whatever you use to access the tape with).
7. Creating an emergency boot floppy for ftape
This section was written by Claus Tondering <ct@login.dknet.dk>.
Once you are the happy owner of a tape drive and several tapes full of
backups, you will probably ask yourself this question: ``If everything
goes wrong, and I completely lose my hard disk, how do I restore my
files from tape?''
What you need is an emergency floppy disk that contains enough files
to enable you to boot Linux and restore your hard disk from tape.
The first thing you should do is to read ``The Linux Bootdisk HOWTO''
written by Graham Chapman <grahamc@zeta.org.au>. That document tells
you almost everything you need to know about making an emergency
floppy boot kit. The paragraphs below contain a few extra pieces of
information that will make your life a bit easier when you follow
Graham Chapman's procedures:
o You don't really need /etc/init, /etc/inittab, /etc/getty, and
/etc/rc.d/* on your floppy disk. If Linux doesn't find /etc/init,
it will start /bin/sh on your console, which is fine for restoring
your system. Deleting these files gives you extra space on your
floppy, which you will probably need.
o Find a small version of /bin/sh. They are frequently available on
the boot floppies that come with a Linux distribution. This again
will give you extra space.
o The /etc/fstab you include on your floppy disk should look like
this:
/dev/fd0 / minix defaults
none /proc proc defaults
Once you have booted from your floppy, give the command:
mount -av
o Make sure your floppy drive is not mounted when you access the
streamer tape! Otherwise you may get the following error message:
Unable to grab IRQ6 for ftape driver
This implies that you MUST load the floppy into a RAMDISK.
This has the unfortunate consequence that the programs needed to
restore the files from the tape must not be located on a separate
floppy disk. You have two options here:
1. You place tar (or cpio or afio or whatever other backup program
you use) on your root floppy disk. (This is where you'll need
all the extra space created in the steps above.)
2. Before you start restoring from tape, copy tar (or cpio or afio
or whatever) to your hard disk and load it from there.
o Apart from your backup program, you will probably need mt on your
root floppy as well.
o Make sure your ftape device (typically /dev/nrft0) is present on
your boot floppy.
o Finally: TRY IT! Of course, I don't recommend that you destroy your
hard disk contents to see if you are able to restore everything.
What I do recommend, however, is that you try booting from your
emergency disks and make sure that you can at least make a file
listing of the contents of your backup tape.
8. Frequently Asked Questions
This is a collection of questions I get asked once in a while, which
could fall into the category of FAQ's. If you feel that there is some
question that ought to be added to the list, please feel free to mail
me (but do include an answer, thanks!).
8.1. Can I exchange tapes with someone using DOS?
No. The DOS software conforms to the QIC-80 specs about the layout of
the DOS filesystem, and it should(?) be a small problem to write a
program that can read/write the DOS format. In fact, I'd bet that
creating a nice user interface would be a bigger problem.
8.2. How do I `....' with tar?
These are really tar questions: Please read the man page and the info
page. If you have not got it either, try `tar --help 2>&1 | more'.
If your version of tar is v1.11.1 or earlier, consider upgrading to
v1.11.2 - This version can call GNU zip directly (i.e.: it supports
the -z option) and has an elaborate help included. Also, it compiles
right out of the box on Linux.
8.3. ftape DMA transfers gives ECC errors
Sadly to say there are some SVGA cards and ethernet cards that do not
decode their addresses correct. This typically happens when the ftape
buffers are in the range 0x1a0000 to 0x1c0000. Somehow, the DMA write
cycles get clobbered and every other byte written gets a bad value
(0xff). These problems are reported to happen with both SVGA and
ethernet cards. We know of at least one (bad?) ATI 16bit VGA card
that caused this.
The easiest solution is to put the card in an 8bit slot (it is often
not enough to reconfigure the card to 8bit transfers). Moving the
ftape buffer away from the VGA range is only a partial solution; All
DMA buffers used in Linux can have this problem! Let us make this one
clear: This has nothing to do with the ftape software.
8.4. insmod says the kernel version is wrong
The insmod program checks the kernel version against the version
recorded in the ftape driver. This is a string in kernel-version.h,
(e.g.: #define KERNEL_VERSION "1.1.72";) which is extracted from the
kernel you are running when you run `make dep'. If you got the error
when you tried to insert the ftape driver, remove the file `kernel-
version.h', type `make dep; make' again and the kernel-version.h file
should be updated. Remember that you will have to do this every time
you change to another kernel version.
8.5. added The v1.1.0 kernel wont compile when ftape support is
(Although I haven't heard a lot of complains, I include it here, just
to be sure)
This was due to a typo (and a hacker who didn't use ftape himself, so
he never got around to actually test the code he wrote). This is
corrected by patch1.gz, which can be found from the usual ftp sites.
8.6. format''' ftape complains that ``This tape has no 'Linux raw
You get this complaint, if you haven't erased your freshly formatted
tape. This is because ftape wants a ``magic header'' on the tape, to
be able that it is allowed to interpret the header segment in it's own
way (eg: file marks). To remove the problem, say `mt -f /dev/nftape
erase'
8.7. binaries/sources/manpages? Where can I find the tar/mt/cpio/dd
All of these tools have been developed by the GNU project, and the
source (and man page) can be fetched from just-about any ftp site in
the world (including ftp.funet.fi, tsx-11.mit.edu, and
sunsite.unc.edu). In any case they can be fetched from the official
GNU home site: prep.ai.mit.edu [18.71.0.38]:/pub/gnu. The latest
versions (by 26. march 94) are:
cpio: 2.3 (cpio-2.3.tar.gz)
dd: 3.9 (fileutils-3.9.tar.gz)
mt: 2.3 (cpio-2.3.tar.gz)
tar: 1.11.2 (tar-1.11.2.tar.gz)
gzip: 1.2.4 (gzip-1.2.4.tar.gz)
They all compile out of the box on Linux v1.0.4 / libc v4.5.19 / gcc
v2.5.8 (The rmt program does not compile out of the box, but it is not
needed as it is only used for accessing the tape drive remotely).
There is a patch for mt included in the ftape distribution, which
makes the mt status command spew out usable information for ftape
drives.
8.8. Where can I obtain the QIC standards?
If you wish to help developing ftape, or add some utility (e.g. a tape
formatting program), you will need that appropriate QIC standards.
The standard(s) to get is: QIC-80 and perhaps QIC-117. QIC-117
describes how commands are sent to the tape drive (including timing
etc), so you would probably never need it. QIC-80 describes the tape
layout, ECC code, standard filesystem and all such ``higher-level''
stuff. You can get the QIC standards from the following address:
Quarter Inch Cartridge Drive Standars, Inc.
311 East Carrillo Street
Santa Barbara, California 93101
Phone: (805) 963-3852
Fax: (805) 962-1541
8.9. What block-size to use with tar
When using compression, and in all general, it can be a benefit to
specify to tar, that it should block the output into chunks. Since
ftape cuts things into 29Kbyte blocks, saying `-b58' should be
optimum.
``Why 29Kbyte?'', I hear you cry. Well, the QIC-80 standard specifies
that all data should be protected by an Error Correcting Code (ECC)
code. The code specified in the QIC-80 standard is known as a Reed-
Solomon (R-S) code. The R-S code takes 29 data bytes and generates 3
parity bytes. To increase the performance of the ECC code, the parity
bytes are generated across 29 1Kbyte sectors. Thus, ftape takes
29Kbytes of data, adds 3Kbytes of ECC parity, and writes 32Kbytes to
the tape at a time. For this reason, ftape will always read 32K byte
blocks to be able to detect (and correct) data errors.
If you are curious, and wish to know more, look in the ecc.c and ecc.h
files, they an explanation of the code and a reference to a textbook
on Reed-Solomon codes.
9. Debugging the ftape driver
9.1. bug? The kernel/ftape crashes on me when I do `...' - is that a
No, that is a feature ;-)
Seriously, reliable software do not crash. Especially kernels do not
or rather should not crash. If the kernel crashes upon you when you
are running ftape, and you can show that it is ftape that is messing
things up, regard it as a Bug That Should Be Fixed. Mail the details
to Bas (<bas@vimec.nl>) and to the tape channel.
9.2. OK, it's a bug ...ehhh... feature - How do I submit a report?
First, make sure you can reproduce the problem. Spurious errors are a
pain in the ass, since they are just about impossible to hunt down :-/
This is a quick check list:
o Kernel version, and patches applied
o ftape version
o tape drive model / manufacturer
o Expansion bus type (EISA, ISA, PCI, or VL-bus)
o What you did to expose the problem
o What went wrong on your system.
o Do not delete the kernel and the ftape.o file. We may want you run
try some patches out or run a different test on your system.
Increase the tracing level to 7 (just below maximum tracing) and run
the offending command again. Get the tracing data from the kernel log
or /proc/kmsg, depending on where you harvest your error messages.
Try to look at what ftape spews out at you. It may look in-
comprehensible to you at first, but you can get valuable information
from the logfile. Most messages have a function name prepended, to
make it easier to locate the problem. Look through the source, don't
just cry ``WOLF!'', without giving it a try. If your version of the
kernel (or ftape for that matter), is ``old'', when compared to the
newest version of the kernel, try to get a newer (or even the newest)
kernel and see if the problem goes away under the new kernel. When
you post your problem report, include the information about ftape
version, kernel version, expansion bus type (ISA, VL-bus, PCI or
EISA), bus speed, floppy controller, and tape drive. State exactly
what you did, and what happened on your system. Some people have
experienced that ftape would not run in a PCI based box, but ran
flawlessly in a normal ISA based 386DX machine (see section ``Getting
PCI motherboards to work with <tt>ftape</tt>'' on PCI machines above)
Also, please think of the poor souls who actually pay the their
Internet access (like me): avoid posting a (huge) log from the ftape
run, without reason. Instead, you could describe the problem, and
offer to send the log to the interested parties.
Send your bug report to <linux-activists@niksula.hut.fi> (remember to
add a `X-Mn-Key: TAPE' line in the header). You might also want to
mail the bug to <bas@vimec.nl>.
9.3. How do I change the trace-level?
You can do this two ways: either change the default trace-level (the
var `tracing' in file `ftape-rw.c') and recompile or say
mt -f /dev/ftape fsr <tracing-level>
The use of the fsr command in mt is a hack, and will probably
disappear or change with time.
9.4. ftape keep saying `... new tape', what do I do?
[You cannot do this anymore; I do not know a way of fixing it]
To get rid of this, do this (blindfold): login as root and say `rmmod
ftape'. ftape should choke a few times, give three segmentation
violations (or so), and give up life.
Check the activity LED on your floppy drive (you do have one, don't
you?). If it is constantly lit, you have turned the floppy cable
upside down somewhere. Check your cable between controller, tape
drive and floppy drive. Usually, one (or more) of the connectors have
been turned upside down, such that pin 1 in one end connects to pin 34
in the other end. (All the even-numbered pins are grounded, so you
wont be able to use your floppy either). Don't worry; this cannot
damage your hardware.
9.5. When I use /dev/nftape, I get garbage ... why?
This was a problem in `the old days', before version 0.9.10.
Nowadays, the non-rewinding devices are working. If you have anything
earlier, I strongly recommend you to update to (at least) the 1.14d
version, preferably v2.02