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- 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
-