What is a safe way to dump data from a tape drive when you are not completely certain what is inside?
I have an old tape drive and old tape that I recently found. I was able to get the tape drive connected to Linux and executed the following commands:
mt -f /dev/nst0 rewind
dd if=/dev/nst0 of=dump.file
My question is, if you do not know what format the tape was created under, what is the safest way to use dd
? On the flip side, if you knew all the files were tar files, what would you then do?
linux tape
add a comment |
I have an old tape drive and old tape that I recently found. I was able to get the tape drive connected to Linux and executed the following commands:
mt -f /dev/nst0 rewind
dd if=/dev/nst0 of=dump.file
My question is, if you do not know what format the tape was created under, what is the safest way to use dd
? On the flip side, if you knew all the files were tar files, what would you then do?
linux tape
1
"Safe" in what sense? What problem(s) are you expecting and wish to avoid?
– ilkkachu
Nov 8 '18 at 13:49
add a comment |
I have an old tape drive and old tape that I recently found. I was able to get the tape drive connected to Linux and executed the following commands:
mt -f /dev/nst0 rewind
dd if=/dev/nst0 of=dump.file
My question is, if you do not know what format the tape was created under, what is the safest way to use dd
? On the flip side, if you knew all the files were tar files, what would you then do?
linux tape
I have an old tape drive and old tape that I recently found. I was able to get the tape drive connected to Linux and executed the following commands:
mt -f /dev/nst0 rewind
dd if=/dev/nst0 of=dump.file
My question is, if you do not know what format the tape was created under, what is the safest way to use dd
? On the flip side, if you knew all the files were tar files, what would you then do?
linux tape
linux tape
edited Nov 8 '18 at 10:45
Fabby
3,93811329
3,93811329
asked Nov 8 '18 at 10:34
user321627user321627
1303
1303
1
"Safe" in what sense? What problem(s) are you expecting and wish to avoid?
– ilkkachu
Nov 8 '18 at 13:49
add a comment |
1
"Safe" in what sense? What problem(s) are you expecting and wish to avoid?
– ilkkachu
Nov 8 '18 at 13:49
1
1
"Safe" in what sense? What problem(s) are you expecting and wish to avoid?
– ilkkachu
Nov 8 '18 at 13:49
"Safe" in what sense? What problem(s) are you expecting and wish to avoid?
– ilkkachu
Nov 8 '18 at 13:49
add a comment |
2 Answers
2
active
oldest
votes
From the this article on dd:
dd reads and writes data by blocks, and can convert the data between
formats. dd is frequently used for devices such as tapes which have
discrete block sizes, or for fast multi-sector reads from disks
dd
will read raw bytes from one file (or device) and write it to another. It doesn't care (or even know) about file systems or file formats. All it sees are blocks of ones and zeros.
Note that you may (or may not) need to swap endian-ness if the tape was written on a big-endian machine, which used to be more popular.
You can do this as described here:
dd if=/dev/nst0 of=dump.file ibs=20b conv=swab
By the way, dd
won't change anything on the input file (if). It only writes to the output file (of). So, it won't harm the data on your tape, if that's what you're worried about.
add a comment |
I've recently written a tool called tapeimgr that automatically extracts all files from a tape. Internally it wraps around dd and mt. More info here:
https://github.com/KBNLresearch/tapeimgr
It also automatically determines the block size (which can be pretty tedious to do manually). Byte swapping is not supported (yet), but having read @layne-bernardo's answer I've put this on the to-do list for an upcoming release. Disclaimer:: so far I've only tested the tool with a limited number of DDS and DLT-IV tapes, as well as a virtual tape library, so use at your own risk!
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
From the this article on dd:
dd reads and writes data by blocks, and can convert the data between
formats. dd is frequently used for devices such as tapes which have
discrete block sizes, or for fast multi-sector reads from disks
dd
will read raw bytes from one file (or device) and write it to another. It doesn't care (or even know) about file systems or file formats. All it sees are blocks of ones and zeros.
Note that you may (or may not) need to swap endian-ness if the tape was written on a big-endian machine, which used to be more popular.
You can do this as described here:
dd if=/dev/nst0 of=dump.file ibs=20b conv=swab
By the way, dd
won't change anything on the input file (if). It only writes to the output file (of). So, it won't harm the data on your tape, if that's what you're worried about.
add a comment |
From the this article on dd:
dd reads and writes data by blocks, and can convert the data between
formats. dd is frequently used for devices such as tapes which have
discrete block sizes, or for fast multi-sector reads from disks
dd
will read raw bytes from one file (or device) and write it to another. It doesn't care (or even know) about file systems or file formats. All it sees are blocks of ones and zeros.
Note that you may (or may not) need to swap endian-ness if the tape was written on a big-endian machine, which used to be more popular.
You can do this as described here:
dd if=/dev/nst0 of=dump.file ibs=20b conv=swab
By the way, dd
won't change anything on the input file (if). It only writes to the output file (of). So, it won't harm the data on your tape, if that's what you're worried about.
add a comment |
From the this article on dd:
dd reads and writes data by blocks, and can convert the data between
formats. dd is frequently used for devices such as tapes which have
discrete block sizes, or for fast multi-sector reads from disks
dd
will read raw bytes from one file (or device) and write it to another. It doesn't care (or even know) about file systems or file formats. All it sees are blocks of ones and zeros.
Note that you may (or may not) need to swap endian-ness if the tape was written on a big-endian machine, which used to be more popular.
You can do this as described here:
dd if=/dev/nst0 of=dump.file ibs=20b conv=swab
By the way, dd
won't change anything on the input file (if). It only writes to the output file (of). So, it won't harm the data on your tape, if that's what you're worried about.
From the this article on dd:
dd reads and writes data by blocks, and can convert the data between
formats. dd is frequently used for devices such as tapes which have
discrete block sizes, or for fast multi-sector reads from disks
dd
will read raw bytes from one file (or device) and write it to another. It doesn't care (or even know) about file systems or file formats. All it sees are blocks of ones and zeros.
Note that you may (or may not) need to swap endian-ness if the tape was written on a big-endian machine, which used to be more popular.
You can do this as described here:
dd if=/dev/nst0 of=dump.file ibs=20b conv=swab
By the way, dd
won't change anything on the input file (if). It only writes to the output file (of). So, it won't harm the data on your tape, if that's what you're worried about.
edited 31 mins ago
answered Nov 8 '18 at 11:43
Layne BernardoLayne Bernardo
1415
1415
add a comment |
add a comment |
I've recently written a tool called tapeimgr that automatically extracts all files from a tape. Internally it wraps around dd and mt. More info here:
https://github.com/KBNLresearch/tapeimgr
It also automatically determines the block size (which can be pretty tedious to do manually). Byte swapping is not supported (yet), but having read @layne-bernardo's answer I've put this on the to-do list for an upcoming release. Disclaimer:: so far I've only tested the tool with a limited number of DDS and DLT-IV tapes, as well as a virtual tape library, so use at your own risk!
add a comment |
I've recently written a tool called tapeimgr that automatically extracts all files from a tape. Internally it wraps around dd and mt. More info here:
https://github.com/KBNLresearch/tapeimgr
It also automatically determines the block size (which can be pretty tedious to do manually). Byte swapping is not supported (yet), but having read @layne-bernardo's answer I've put this on the to-do list for an upcoming release. Disclaimer:: so far I've only tested the tool with a limited number of DDS and DLT-IV tapes, as well as a virtual tape library, so use at your own risk!
add a comment |
I've recently written a tool called tapeimgr that automatically extracts all files from a tape. Internally it wraps around dd and mt. More info here:
https://github.com/KBNLresearch/tapeimgr
It also automatically determines the block size (which can be pretty tedious to do manually). Byte swapping is not supported (yet), but having read @layne-bernardo's answer I've put this on the to-do list for an upcoming release. Disclaimer:: so far I've only tested the tool with a limited number of DDS and DLT-IV tapes, as well as a virtual tape library, so use at your own risk!
I've recently written a tool called tapeimgr that automatically extracts all files from a tape. Internally it wraps around dd and mt. More info here:
https://github.com/KBNLresearch/tapeimgr
It also automatically determines the block size (which can be pretty tedious to do manually). Byte swapping is not supported (yet), but having read @layne-bernardo's answer I've put this on the to-do list for an upcoming release. Disclaimer:: so far I've only tested the tool with a limited number of DDS and DLT-IV tapes, as well as a virtual tape library, so use at your own risk!
answered Dec 5 '18 at 17:39
johanjohan
1512
1512
add a comment |
add a comment |
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1
"Safe" in what sense? What problem(s) are you expecting and wish to avoid?
– ilkkachu
Nov 8 '18 at 13:49