<jo@correct.nl>
This is a very incomplete attempt to create a FAQ for the Ftape Floppy Tape Device Driver.
You might encounter references to the following addresses while reading this document:
<http://www.torque.net/ftape/>
Thanks to Grant R. Guenther <grant@torque.net>
<http://www.info-systems.com/ftape/>
Thanks to Jakob Curdes <jc@info-systems.com>
<http://www.newwave.net/~joshg/ftape/>
Thanks to Josh Goins <joshg@newwave.net>
There is surely quite a lot missing. Please feel free to improve this FAQ. The preferred way of doing this is to post to the Ftape Mailing List in case you have a question that isn't answered here.
Also, if you are already reading the list regularly and have the impression that some questions occur again and again, feel free to send that question and possibly an answer in the format indicated below to the maintainer of the Ftape FAQ AND to Ftape Mailing List.
If you make FAQ related postings, then please DON'T FORGET to prepend the word "[FAQ]" to the subject of your posting. Please don't add the word "FAQ" to the subject if you post something that isn't related to the FAQ.
That's all for now.
Always the latest stable version which is _supposed_ to be available from ftp://sunsite.unc.edu/pub/Linux/kernel/tapes and http://www-math.math.rwth-aachen.de/~LBFM/claus/ftape/
At time of this writing the latest stable version is ftape-4.02
.
<answer from Claus Heine>
The default version of Ftape included in the 2.0.xx kernel sources is 2.08 or 2.09 and is very out of date. Please update the Ftape drivers to the latest from the Ftape Home Page.
<answer from Tim Jones>
You need to add -D__SMP__
to the KERNEL_OPT
variable in the
file MCONFIG
. In newer ftape
versions you only need to
uncomment a certain line in the MCONFIG
file.
<answer from Claus Heine>
Ignore the depmod error messages. The problem is that the Ftape modules
have to be compiled without the version checksum feature (i.e.
CONFIG_MODVERSIONS
) with 2.0.* kernels. This causes no problem, even
when the modules are used with a kernel that has support for this feature;
only that depmod
wrongly complains about undefined symbols. Ignore the
complaints of depmod
and try to insert the modules despite of these
complaints:
modprobe zftape
If this fails, something is wrong.
<answer from Claus Heine>
The insmod
program can check the kernel version against the
version that Ftape was compiled for in two ways: It can directly
compare the kernel version number recorded in the Ftape module against
the version of the running kernel, or, if both the kernel and
Ftape is compiled with versioned symbols, compare the version of
the used kernel symbols.
If you have upgraded your version of GCC to v2.7.0 or later, you must recompile the modules utilities with gcc v2.7.x.
Newer versions of insmod
allows you to "force" insertion of
a module into the kernel, even though the version string is incorrect.
<from the Ftape-Howto>
Did you remember to apply the ksyms.c
patch to the kernel? If
not, read the README.linux-1.2
file in the source distribution.
<from the Ftape-Howto>
The modversions.h
file is created when the kernel is compiled
with the configuration item CONFIG_MODVERSIONS
turned on. With
this option enabled, the file will be created during the make dep
step.
One more handy tip is that a make mrproper
will remove
/usr/include/linux/modversions.h
. You will need to reconfig
the kernel and do a make dep
to get the file back.
<from the Ftape-Howto>
When you say `yes' to CONFIG_MODVERSIONS
during `make config
',
all the symbols exported by the kernel, i.e: the symbols that the
loadable modules can "see", are augmented to include a checksum
across the types of the call/return parameters. This allows
insmod
to detect whether the definition of a variable or function
in the kernel has changed since the time when Ftape was compiled.
This ensures a high degree of safety, such that you do not crash the kernel because you used an outdated module with your kernel.
If you enable CONFIG_MODVERSIONS
in the kernel, make sure you have
-DMODVERSIONS -include /usr/include/linux/modversions.huncommented in the MODULE_OPT line in the Ftape Makefile. Conversely, if you do not have CONFIG_MODVERSIONS enabled, make sure you have it commented out.
<from the Ftape-Howto>
There are (at least) two possible sources of the problem:
/lib/modules/misc
instead of
/lib/modules/uname -r/misc
As modprobe
searches in /lib/modules/misc/
last there might be
an old ftape.o
module floating around in /lib/modules/
uname -r/misc
which modprobe
finds first (uname -r
stands for the kernel version).
Remove the old ftape.o
module.CONFIG_FTAPE
) and
recompile and install it.<answer from Claus Heins>
You are probably trying to use the same IRQ and DMA settings as your on-board FDC. This does not work in versions of Ftape prior to 3.03b. Please update the Ftape Drivers to the latest from the Ftape Home Page.
<answer from Tim Jones>
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.
<from the Ftape-Howto>
You should only see this is you are trying to insmod
the
ftape.o
module. Try running swapout
first. It is provided
with the standalone Ftape source. It doesn't appear in the
Ftape source that's provided with the kernel.
Here's an example of how you can set your rc.local file to use it.
# Install the Floppy Tape Driver
if [ -f /boot/modules/`uname -r`/misc/ftape.o ]; then
echo Installing ftape for Linux `uname -r`
swapout
insmod /boot/modules/`uname -r`/misc/ftape.o
fi
Please note that you won't have this type of problem if you compile the Ftape driver into the kernel.
<from the Ftape-Howto>
The compile-time options NO_TRACE
and NO_TRACE_AT_ALL
in Ftape
control the amount of system logging. Add whichever is appropriate to the
FTAPE_OPT
line in the Makefile and recompile.
<from the Ftape-Howto>
There are three ways you can do this (in order of personal preference).
While we're at it, here are the meanings of the various trace levels.
/sbin/insmod ftape.o tracing=<tracing-level>
fsr
option
in mt
to be used to set the tracing level. zftape
does not
have this hack.
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.
tracing.c
contains a line int tracing = 3;
.
Change the 3 to whatever is appropriate and recompile.
<From the Ftape-Howto>
Check the Ftape Home Page. for an even newer version. Then check the FAQ contained in the that package if your problem is listed there. Next, try to check if the manual that comes with the Ftape distribution mentions your problem.
There is no need to read the entire manual, simply check the "Concept Index" if it contains a keyword that might be related to your problem, then jump to the proper location in the manual.
If you are still convinced you've found a bug, then post a general question describing the problem to the Linux-Tape Mailing List , but do not attach your entire Ftape error-log. If we've seen the problem before, we'll let you know where the resolution effort stands. If we haven't, the Ftape maintainer will most likely request that you send him the entire Ftape error-log (snipped from your system messages file).
<answer from Tim Jones>
You can achieve quite respectable backup and restore speeds with Ftape: a Colorado DJ-20 and an Adaptec 1542CF controller, has been measured at 4.25Mbyte/min sustained data transfer rate (no compression) across a 70Mbyte tar archive, while comparing the archive on the tape with data on an 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).
There has been a few reports of "shoeshining". This is when the tape just seems to run back and forth endlessly. This has been seen on a Jumbo 250 (74407.3051@compuserve.com) and on an Iomega 250 Ditto Insider (tom@opus.cais.com). In the latter case it has been narrowed own to using an ELF Linux and running off a SCSI hard disk (connected to an Adaptec 1542cf). Please contact me if you have an update to this problem.
<from the Ftape-Howto>
Probably not. If you are backing up a large number of < 2K files, you're just going to have to live with it. In this event, the repositions are caused by file system access overhead. If you are backing up a normal system's files, this may be caused by slop or media stretching in the tape cartridge. By simply retensioning the tape, you should see this go away. Try
ftmt -f /dev/zqft0 reten
to retension the tape. If retensioning doesn't solve this, and it's only
happening on certain tapes, it might be wise to replace the tapes in question.
<answer from Tim Jones>
If you use afio as your backup tool you can set it to write a very large number of buffers in one hit by using the -c flag. Make it large enough so that you supply enough data for most of a single end-to-end pass over the tape. For my system, the following streams quite nicely - stopping relatively few times per tape pass on an unloaded system:
find /usr/local -xdev -print | afio -o -v -f -b 10240 -c 800 /dev/qft0
In my case I'm writing 800 x 10240 bytes per tape write, i.e. about 8MB.
haven't experimented that much with these settings - so someone might like
to establish more optimal ones.
Presumably other backup utilities could be modified to use a similar technique.
<answer by Michael Hamilton>
GNU tar doesn't use buffering in this way. The commercial backup program "bru" is able to multi-buffer using shared memory; this works only when writing compressed archive with bru (regardless whether you use Ftape's builtin compression)
Another way to overcome the problem might be to use more dma buffers in the Ftape kernel driver like:
mt -f /dev/qft0 setdrvbuffer $((6*32786))
$((6*32786)) should be expanded by your shell when using a Bourne
compatible one. This has a negative impact on the system's memory pool:
Ftape's dma buffers cannot be used by any other part of the kernel nor
by any other application. And kernel memory cannot be swapped out. If you
decide to use this kind of multi-buffering then you should unload the driver
as soon as it isn't needed any longer.
<answer by Claus Heine>
Not if you are using the latest version of the Ftape drivers from the Ftape Home Page.
To format a QIC-80, TR-1, TR-3, QICWide 3010 or 3020 tape, get the
latest version of ftape
and the latest version of the
ftape-tools
package (from the same location) and read the
documentation of the ftformat
utility which is included in the
ftape-tools
package.
<answers from Tim Jones and Claus Heine>
It isn't possible to format Ditto 2GB
tapes with Ditto 2GB
tape drive, and it isn't possible at all to re-format Ditto 2GB
tapes in a way that they still can be used by a Ditto 2GB
tape
drive.
This is a hardware limitation of the Ditto 2GB
tape drive. It
can't be helped at the software level, i.e. it isn't ftape's
fault.
No, the Ditto Max
can't format tapes.
This is a hardware limitation of the Ditto Max (Pro)
tape drive. It
can't be helped at the software level, i.e. it isn't ftape's
fault.
If you look at the difference, you will notice that Ftape always detects 2784 sectors more than DOS.
The number that Ftape reports is correct (of course :-)
. Each
correctly formatted QIC-3020 tape has 2784 sectors at fixed positions
that are marked in the bad sector map. To quote from the specs:
Tracks 5,7,9,11,13,15,17,19,21,23,25 and 27 within 4 segments of either EOT or BOT are prone to increased error rates due to hole imprints. Therefore, these regions shall be mapped as bad at format time and entered in the bad sector map by indicating that all sectors within the identified segments are bad.
This gives 12 tracks * 2 * 4 segments * 29 sectors == 2784 sectors.
So Ftape choose to report the real number of sectors that cannot be used on the tape, while DOS gives a more optimistic number giving a better indication of tape quality. (Ftape's behavior might change in the future to detect correct formatting and display the separate numbers. It has rather low priority though).
QIC-3010 are alike QIC-3020 tapes regarding this.
<from the Ftape-Howto>
Yes. The driver merely updates an internal counter when those commands are issues. The tape should move to the proper location on the next read or write access to the tape drive.
<from the Ftape-Howto>
zftape
requires the data to be written in multiples of a fixed minimal
block size. This is a very usual behavior for a tape device. There are three
ways to get rid of those errors:
mt -f /dev/qft0 setblk 5120
mt -f /dev/qft0 setblk 0
to switch Ftape to variable block size mode and be able to write the
data in arbitrary portions to the tape (BUT: the builtin compression doesn't
work with this setting). When you intend to use "KBackup" then this is the
only way to make it work together with Ftape (it _may_ work, don't know
if it does)
afio -b 10k ...
You may want to read the section "Tape blocks" of the manual (use its "Concept index" to directly jump to that section)
When using GNU tar's builtin compression with GNU tar versions prior to
tar-1.12 one needs to run tar with the --block-compress
switch to
re-block
the output to the tape. Otherwise tar will compress the data
it reads, and write it in arbitrary portions to the tape.
Example :
tar -czvf /dev/qft0 --block-compress /etc
WARNING: One shouldn't use tar's builtin compression with large backups as it makes the entire data stream one huge compressed block. If such archives are corrupted right at the beginning it will be very difficult to recover.
<answer by Claus Heine>
When you get next messages, this could be interesting for you !
The explanations:
"FDC" menas "Floppy Disk Controller". The problem is that your floppy disk controller must be able to support something that is called "perpendicular mode" to be able to read and write QIC-3020/QIC-3010 cartridges (i.e. TR-3 cartridges). To my knowledge all FDCs that are capable of at least 1Mbit/sec data transfer rate also support "perpendicular mode" ("perpendicular" refers to the direction of magnetization of the ferro-magnetic particles on the tape).
This means that you need to purchase another FDC. Either look around some computer stores and ask for an IO controller cards that is able to support 2.88 Mb floppies (which imlies 1Mbit data transfer rate and perpendicular mode).
Or get one of the so called "high speed" controllers that even support 2Mbit/sec data transfer rate. Those controllers are based on an Intel 82078 FDC. Iomega sells such a card under the name "Ditto Dash". I think Exabyte sells their 2Mbit controllers separately, too, whereas Seagate ships its TR-3 drives (i.e. the TST-3200) together with such a controller.
<answer from Claus Heine>
I assume that the following is the problem: The Ftape module is loaded OK into the kernel:
/usr/src/ftape-3.03b-970603# lsmod
Module Pages Used by
ftape 22 0
but then this happens:
$ ftmt -f /dev/qft0 status
ftmt: /dev/qft0: No such device
Solution You need to load the zftape.o module as well. With Ftape-3.* the ftape.o module doesn't implement the VFS interface. This is done by zftape.o.
<answer from Claus Heine>
The "device busy" messages can only occur while the Ftape devices are still held open by some program. As soon as the close() system call has completed the busy flag is cleared. May be "bru" or some other program has still forked off a child that dies delayed?
Yes, this will reproduce the problem, it seems:
tar -cvvzf /dev/nqft0 --block-compress ; mt rewind
You can skip the "--block-compress" if using the most recent version
of GNU tar.
However, this is not a bug of Ftape. It seems that the parent tar process exits before its child has closed the tape device. I know, however, from hacking the tar code ages ago, that tar properly waits for its parent to die.
However, the busy message simply means that the "busy" variable is still held at 1 (zftape/zftape-init.c). And this simply means that there still is a process hanging around that holds the tape device open.
I think I have it (only for the case of tar 'cause I have the source code.
If on uses tar with compression, then it forks a child which will become the compressor bei execing "gzip" or whatever. Before the call to execlp() the child will fork off a grand child of its parent tar. That grandchild will do the actual tape I/O.
tar - fork() - write to child tar
|
child tar - fork() - gzip (will pipe to grand child tar)
|
grand child tar - open archive.
Now, parent tar only waits for its child to die. gzip surely doesn't wait for the grand child as the gzip is a result of an execlp().
What I don't know is whether the grand child should be implicitly waited for by the parent tar, or if the wait() function also waits for grand childs.
But this seems to be the problem: the parent tar already has exited while its grandchild still is busy closing the archive. One hardly will notice this problem if the close() happens fast (i.e. regular files, block devices, also other tape devices?), but it isn't a bug in Ftape, but either in the backup programs or in the kernel or maybe libc exit code.
Don't know if the considerations above also apply to bru. If there is no grandchild and the parent process properly waits for its childs then there shouldn't be a problem.
<answer from Claus Heine>
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 | less
If your version of tar
is v1.11.1 or earlier, consider
upgrading to v1.11.8 - 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.
<from the Ftape-Howto>
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 and write 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, for an explanation of the code and a reference to a
textbook on Reed-Solomon codes.
<from the Ftape-Howto>
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 (as of September 12
1996) are:
cpio: 2.4.2 (cpio-2.4.2.tar.gz)
dd: 3.13 (fileutils-3.13.tar.gz)
mt: 2.4.2 (cpio-2.4.2.tar.gz)
tar: 1.11.8 (tar-1.11.8.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
.
<from the Ftape-Howto>
It is not bad as such to compress data twice (which would be the case when using tapers compression together with zftape's compression) but it doesn't make any sense. You won't gain much further compression, but only waste CPU cycles.
Tapers compression should be quite safe, as taper compresses single files; in contrast to tar -czf ... which makes the entire data stream a large compressed block of data, which is really a bad thing with serious backups as a single bad byte at the beginning of the archive can make the entire archive unusable, well, it will be at least quite difficult to recover.
<Answer from Claus Heine>
gzip -9 is better (i.e. one gains higher compression). zftape's compression is comparable with the Un*x compress program, but should be faster, and is faster than gzip.
<Answer from Claus Heine>
Use the zftape interface, but don't load the zft-compressor module.
The device then becomes /dev/qft0
.
<answer from Tim Jones>
You get this complaint if you haven't erased your freshly formatted tape. This is because Ftape expect a "magic header" on the tape, to be able that it is allowed to interpret the header segment in its own way (eg: file marks). To remove the problem, say
mt -f /dev/nftape erase
<from the Ftape-Howto>
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.
<From the Ftape-Howto>
(EOM is "End Of recorded Media", the position right after all data already recorded to the tape)
One cannot use tape "files" like files on an ordinary file system.
In principle, a tape doesn't allow anything but appending new data at EOM. However, if one positiones just in the middle of the already recorded data AND starts writing, then the driver first deletes all following files (thus moving the EOM to the actual position) and then starts writing.
Thus, the new EOM after finishing the write process, is then after the newly recorded data.
One of the consequences of the above is, of course, that writing to the tape in the middle of the already recorded area, is destructive in the sense, that it not only overwrites the "file" the tape is positioned at, but also deletes all following files.
<from the Ftape-Howto> <Answer from Claus Heine>
It probably didn't work before because you didn't use a
mt -f /dev/rft0 erase
before writing data to the cartridge. THIS ISN'T necessary any more.
But, hey, what does mt fsf? Tape drives don't store files in the sense that you can use
cp somefile /dev/my_what_ever_tapeor be able to mount the tape drive like you could mount a harddisk. You can't do nothing with a tape drive but write data to it in a sequential manner.
As this is quite inconvenient, somebody invented something which is known under the name file mark or eof mark (eof == End Of File). Those marks don't separate files that have been backed up to the tape device, but only separate blocks of data (whatever data that might be).
Normally, the kernel tape device drivers take care of writing file marks when the tape device is closed, i.e.
tar -cf /dev/nqft0 /bin
tar -cf /dev/nqft0 /etc
mt -f /dev/nqft0 rewind
would result in a backup of all files under /bin and /etc. When
the first tar finishes, the kernel driver will take care of writing
a file mark to the tape at the current tape position, and when the
second tar process has finished, another file mark is written to the
tape cartridge at that position.
Now, the sense of those file marks is, that it is possible to skip between different archives on the tape more quickly than would be possible with reading the data back.
The commands to do that are:
fast skip to the next file mark towards EOT (End Of Tape)
fast skip to the next file marks towards BOT (Begin Of Tape)
mt -f /dev/nqft0 rewind
mt -f /dev/nqft0 fsf
tar -xvf /dev/nqft0
<Answer from Claus Heine>
When Ftape was young there were two versions of the floppy tape driver, one of them was called zftape because of its built-in user-transparent on-the-fly compression. Whether such a thing is a feature or a bug ('cause this needn't be done in kernel space) is another question. However, the ioctl interface and file mark handling provided by zftape was much better and had less bugs. And zftape allows to use floppy tape cartridges with different OS. Well, you can't exchange data, but zftape won't overwrite volumes created by your Windoze program, and vice versa.
Nowadays, Ftape is name of the entire floppy tape driver package AND ftape.o is the file-name of the kernel module that implements the low-level hardware support. zftape has ceased to exist as a separate package, but the new Ftape versions (since ftape-3.00) contain a zftape.o module that needs to be loaded on top of ftape.o (i.e. you need to load BOTH modules to be able to access your floppy tape drive) and implements the file system interface and the advanced (?) features of the previous verions zftape.
<Answer from Claus Heine>
Well, the rewinding tape devices rewind the tape to BOT (Begin Of Tape) when the device is closed, i.e.
tar -cvf /dev/qft0 /bin
will rewind the tape cartridge when the tar job has finished. In contrast,
tar -cvf /dev/nqft0 /bin
will NOT rewind the tape cartridge and leave the tape R/W head at its
current position.
Rewinding devices should be used when performing a single backup, non-rewinding devices can be useful when doing multiple backups as one doesn't need to space to EOM (End Of recorded Media) before appending another archive.
Non-rewinding devices MUST be used when sending any of the tape motion command to the tape drive, such as
mt -f /dev/nqft0 fsf
, because when the mt process finishes then the tape device is closed
which would result in rewinding the cartridge with the rewinding devices.
<Answer from Claus Heine>
Well, it depends. If the tape is still positioned inside the volume just written, "mt bsf 1" (or equivalently "mt bsf") will backspace just to the beginning of that volume (this is how "tar --verify" works). If the tape is already positioned AFTER the filemark that marks the end of the last written volume, then you need to issue "mt bsf 2"
The logic behind this is as follows:
"MTBSF count" backspaces over count file marks, stops, and then
positions on the EOT
side of the last skipped file mark. This means,
an "mt bsf 2" will position right at the beginning of the previous
volume.
<answer form Claus Heine>
You are right: auto-rewind means, the tape is rewound when the tape device is closed, non-rewinding means, the tape isn't automatically rewound when the tape device is closed (but you can, of course, use the tape motion commands BSF/FSF etc. to position the tape head at every position you like).
<answer form Claus Heine>
A record is the minimal amount of bytes that will be accepted by the tape in one read/write operation (except in "variable block size mode" where it just should be the amount of data actually written in a single write operation??).
For zftape every read and write access has to be a multiple of a fixed
block size (fixed, but tunable with MTSETBLK
). This block size is a
"tape record" (as mentioned in the GNU mt man page and defaults to
10kb for zftape.
A "file" (in the sense of the mt man page) is a, well, misleading terminus. What is meant is an area of the tape between two file marks. This is not a file like a file on the file system, in the sense that it could have a name, file access modes, could be moved or copied with cp, mv, rm etc.
Instead, It simply is the area of the tape that was recorded in one
backup session, its end is marked by a tape file mark, and its
beginning is delimited by either BOT
or the file mark of the previous
tape "file". That tape "files" are the things that can be skipped with
the MTBSF/FSF
commands.
<answer form Claus Heine>
We try to answer the followong questions :
If you want to "erase" an entire cartridge, then simply do:
mt -f /dev/qft0 erase
This will erase the volume table (i.e. the "file marks").
Pre-ftape-3.x releases of zftape and ftape used to allow overwriting of already existing volumes on a cartridge. I have removed this feature as it was reported that it already has caused data-loss with some backup programs.
If you indeed need to remove some volumes on the tape then you should use the
vtblc
program that comes with the ftape-tools
package which can be
down-loaded from the same locations as the ftape
kernel driver
package. Please refer to the documentation which is contained in the
ftape-tools
package for more information.
If you simply want to reuse old tapes, then it suffices to do
mt rewind
If the tape is at BOT (Begin Of Tape) then every write access to the tape will silently erase all file marks and overwrite the data already existing on the tape.
<answer by Claus Heine>
Here is as little perl/bash script that lists the contents of a cartridge using the zftape specific "volinfo" ioctl. Hope this shows how to handle this kind of stuff.
What it basically does is the following:
claus@thales:~$ mt volinfo
file number = 1
block size = 10240
physical space used = 522.0 kilobytes
real size of volume = 520.0 kilobytes
Parse the ouput and place the values in appropriate variablesThe Perl Script
#!/usr/bin/perl
#
# Copyright (C) 1997 Claus-Justus Heine
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2, or (at your option)
# any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; see the file COPYING. If not, write to
# the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
#
# This script implements a simple contents listing for the zftape
# package using the MTIOCVOLINFO ioctl.
#
$version = <<EOT;
listtape-1.0 -- a perl script to list the contents of a floppy tape cartridge
under Linux using the zftape driver
RCS \$Revision$
RCS \$Date$
EOT
$tapedev = "/dev/tape";
$usage = <<EOT;
Usage: listtape [options ...]
Mandatory or optional arguments to long options are mandatory or optional
for short options too.
-f, --file=FILE Tape device to use. Default is "/dev/tape".
-h, --help Print this help.
-? Same as '-h'.
--usage Same as '-h'.
-V, --version Print version information.
Author: Claus-Justus Heine <claus\@momo.math.rwth-aachen.de>
EOT
while ($ARGV[0] =~ /^-/) {
$_ = shift;
if (/--file/) {$_ = shift; $tapedev = $_; next;}
if (/-f/) {$_ = shift; $tapedev = $_; next;}
if (/--help/) { print $usage; exit 0; }
if (/-h/) { print $usage; exit 0; }
if (/--usage/) { print $usage; exit 0; }
if (/-\?/) { print $usage; exit 0; }
if (/--version/) { print $version; exit 0; }
if (/-V/) { print $version; exit 0; }
die $usage;
}
&open_tape($tapedev, "status");
while(<FTMT>)
{
$online = 1 if (/.*online.*/);
}
if (! $online) { die "No cartridge present.\n"; }
&mtop($tapedev, "rewind");
printf "%11s%12s%20s%20s\n",
"file number", "block size", "volume size", "tape space";
while (1)
{
&open_tape($tapedev, "volinfo");
while (<FTMT>) {
if (/^file number\s*=\s*([0-9]*)$/) { $filenumber = $1; }
if (/^block size\s*=\s*([0-9]*)$/) { $blocksize = $1; }
if (/^physical space used\s*=\s*([[0-9]*.*)/) { $rawsize = $1; }
if (/^real size of volume\s*=\s*([[0-9]*.*)/) { $size = $1; }
}
close(FTMT);
if (&mtop($tapedev, "fsf 1") != 0) {
&mtop($tapedev,"rewind");
print "\nRemaining space: $rawsize\n";
print "Tape block size: $blocksize\n";
exit 0;
}
printf "%6d %5d %20s%20s\n",
$filenumber, $blocksize, $size, $rawsize;
}
sub mtop
{
local ($tape, $operation) = @_;
local ($exitval);
system "ftmt -f $tape $operation > /dev/null 2>&1";
}
sub open_tape
{
local ($tape, $operation) = @_;
local ($command);
$command = "ftmt -f " . $tape . " " . $operation . " |";
open(FTMT, $command) || die "Couldn't open $command -- $!\n";
}
The Bash Script
#! /bin/bash # # Copyright (C) 1997 Claus-Justus Heine # # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 2, or (at your option) # any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program; see the file COPYING. If not, write to # the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. # # This script implements a simple contents listing for the zftape # package using the MTIOCVOLINFO ioctl. # # # insert better option parsing here # TAPEDEV=${1-/dev/tape} if ! echo $TAPEDEV | grep "/dev/n" then TAPEDEV=/dev/n$(basename $TAPEDEV) fi if ! [ -c $TAPEDEV ] then echo $TAPEDEV is not a character device! 1>&2 exit 1 fi if ! mt -f $TAPEDEV rewind then echo Could not rewind $TAPEDEV - no cartridge present? 1>&2 exit 1 fi echo -e "\nContents of $TAPEDEV:\n" printf "%11s%12s%20s%20s\n" "file number" "block size" "volume size" "tape space" trap "rm -f /tmp/$0.$$" exit while true do if ! foo=$(mt -f $TAPEDEV volinfo |cut -f 2 -d =) then echo $TAPEDEV doesn\'t seem to be a floppy tape device 1>&2 exit 1 fi # # "echo foo | read foo" will not work as the "read foo" is executed in # another shell. # echo $foo > /tmp/$0.$$ read file blksz used usedunit size sizeunit < /tmp/$0.$$ if ! mt -f $TAPEDEV fsf 1 > /dev/null 2>&1 then echo -e "\nRemaining space: $used $usedunit" echo -e "Tape block size: $blksz" if ! mt -f $TAPEDEV rewind then echo Rewind of $TAPEDEV failed 1>&2 exit 1 fi exit 0 fi printf "%6d %5d %20s%20s\n"\ $file $blksz "$size $sizeunit" "$used $usedunit" done
<answer from Claus Heine>
I was the UNIX Product Manager at Archive Corp (Prior to the Conner/Seagate mess) and we performed extensive tests of tape media for compatibility certification, including retentivity, flaking and length consistancy. Based on the results of the tests, we selected the best of these certified manufacturers' products to private label as our own media. Here is the order in which we selected vendors up through 1995 (when I lost contact with the ATI group):
Otherwise, we had entries in our search from other vendors which were generally a private-labelled version of one of the major labels above. The exceptions were Verbatim and DIC. Both of these manufacturer's media had fall-out rates and length discrepancies that were so high that we would not certify them and even warned customers about them indicating that we could not offer any sort of guarantee that they would get a good backup using the media from these manufacturers.
In addition, since coming to EST, I've found that Verbatim media is still not worth the money saved in purchasing it. We have 11 of their TR-Extra and QIC-Extra (QICXL) tapes that were useless after fewer than 20 passes each.
While this is my personal opinion, it is based on over 9 years of experience with this very question, I strongly recommend Imation/3M media for QIC/Travan user, Fuji media 4MM users, Exabyte/Fuji for 8MM and DEC labelled media for DLT users.
<answer from Tim Jones>
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, -117, -3010, and 3020. QIC-117 describes how commands are sent to the tape drive (including timing etc), so you would probably never need it. QIC-80/3010/3020 describes higher level part, such as tape layout, ECC code, standard filesystem. You can get the QIC standards from the following address:
Quarter Inch Cartridge Drive Standards, Inc.
311 East Carrillo Street
Santa Barbara, California 93101
Phone: (805) 963-3853
Fax: (805) 962-1541
Note: They are registered as `Freeman Associates, Inc' in the phone book.
<from the Ftape-Howto>
Yes, if you are using version ftape-3.x
or later of the Ftape
drivers from the
Ftape Home Page or from
ftp://sunsite.unc.edu/pub/Linux/kernel/tapes.
<answer from Tim Jones>
As the Ditto 2GB is a Tr-3 tape (though it can only store 1GB instead of the 1.6GB you get with a regular Tr-3 drive) you need an FDC (FDC means: Floppy Disk Controller) that is capable of at 1Mbit/sec transfer rate. You don't need to worry about this if you have an accellerator card (i.e. the Ditto Dash controller). Otherwise try to purchase an FDC that claims to be capable of driving 2.88Mb floppies because this implies that the FDC is capable of 1Mbit transfer rate.
Ftape prints the maximum data rate of the FDC to the kernel log files like this:
ftape-ctl.c (ftape_init_drive) - Highest FDC supported data rate: 500 Kbps.
<answer from Claus Heine>
Yes, if you are using version ftape-4.02
or later of the
Ftape drivers from the
Ftape Home Page or from
ftp://sunsite.unc.edu/pub/Linux/kernel/tapes.
<answer from Claus Heine>
Yes. But if you want to use the 5GB (10GB with compression) cartridges
you don't need it. With ftape
there doesn't seem to be any
difference between the Ditto Max
and the Ditto Max Pro
.
<answer from Claus Heine>
You can subscribe to that list by sending mail to
majordomo@vger.rutgers.edu
with the single line
subscribe linux-tape
in its body. Please store the answer you get from majordomo in a safe place
because it contains instructions how to UNSUBSCRIBE
from the mailing list.
<answer from Claus Heine>
Send mail to
majordomo@vger.rutgers.edu
with the single line
unsubscribe linux-tape MY@EMAIL.ADDRESS
where MY@EMAIL.ADDRESS
has to be replaced by the email
address that you used when subscribing to the list. Note that you must
have received an email with instructions how to unsubscribe from the
mailing list at the time you subscribed to it.
<answer from Claus Heine>
<http://www.uwsg.indiana.edu/usai/library/backups.html>
More links wanted !!!