Raw Disk Copy doesn't work

QNX Newsgroups (Archives) qdn.public.qnx4
1

I’m trying to make a backup using the raw disk copy method. It doesn’t seem
to work, and I’m wondering if someone might be able to help (or, at least
explain why).

I simply try to cat the contents of the first raw disk (6GB) to a file on a
SMB filesystem. For example:

cat /dev/hd0 > /SMBfilesystem/backupfile

I’m thinking that the 2GB size limit for a file might be the cause, because
that’s the resulting size of the …/backupfile. I tried a couple of
tests…

I appended to the …/backupfile with: print “growing the file” >>
/SMBfilesystem/backupfile. Surprisingly enough, the file grew!?

Earlier, when accessing /dev/hd0, I checked “sin fi” and found that the
“position” read nnnnM/ 2147M. Therefore, I tried “dd” to seek near the
so-called end-of-file: dd if=/dev/hd0 of=/SMBfilesystem/backupfile
ibs=1000k obs=1000k skip=2000. The resulting file was less than 100 MB.

Test results: I can write (append) to a file past 2GB, but I can’t read a
raw disk past 2GB. Hmmmmm.

Could it be Fsys, or Fsys.eide? I’m using LBA mode, which I want.

Thanx in advance,
John Colburn

P.S. Here’s something interesting that I discovered.

In the example above (cat /dev/hd0 > /SMBfilesystem/backupfile), the data
was transferred at a certain speed. If, while this process was running, I
ran a similar process (cat /dev/hd0 > /SMBfilesystem/backupfile.2), the
/SMBfilesystem/backupfile was growing about 10 times faster! When I used
the dd command (above) instead of cat, the speed gain was in the order of 30
times!

2

Why don’t you just Tar&Gzip the whole directory tree?
If you Raw disk copy and the target has some different bad sectors you might not be pleased with the
result.
-Paul

John Colburn <jcolburn@city.winnipeg.mb.ca> wrote in message news:92vgtp$5n6$1@inn.qnx.com…

I’m trying to make a backup using the raw disk copy method. It doesn’t seem
to work, and I’m wondering if someone might be able to help (or, at least
explain why).

I simply try to cat the contents of the first raw disk (6GB) to a file on a
SMB filesystem. For example:

cat /dev/hd0 > /SMBfilesystem/backupfile

I’m thinking that the 2GB size limit for a file might be the cause, because
that’s the resulting size of the …/backupfile. I tried a couple of
tests…

I appended to the …/backupfile with: print “growing the file”
/SMBfilesystem/backupfile. Surprisingly enough, the file grew!?

Earlier, when accessing /dev/hd0, I checked “sin fi” and found that the
“position” read nnnnM/ 2147M. Therefore, I tried “dd” to seek near the
so-called end-of-file: dd if=/dev/hd0 of=/SMBfilesystem/backupfile
ibs=1000k obs=1000k skip=2000. The resulting file was less than 100 MB.

Test results: I can write (append) to a file past 2GB, but I can’t read a
raw disk past 2GB. Hmmmmm.

Could it be Fsys, or Fsys.eide? I’m using LBA mode, which I want.

Thanx in advance,
John Colburn

P.S. Here’s something interesting that I discovered.

In the example above (cat /dev/hd0 > /SMBfilesystem/backupfile), the data
was transferred at a certain speed. If, while this process was running, I
ran a similar process (cat /dev/hd0 > /SMBfilesystem/backupfile.2), the
/SMBfilesystem/backupfile was growing about 10 times faster! When I used
the dd command (above) instead of cat, the speed gain was in the order of 30
times!

3

“John Colburn” <jcolburn@city.winnipeg.mb.ca> wrote in message
news:92vgtp$5n6$1@inn.qnx.com…

I’m trying to make a backup using the raw disk copy method. It doesn’t
seem
to work, and I’m wondering if someone might be able to help (or, at least
explain why).

I simply try to cat the contents of the first raw disk (6GB) to a file on
a
SMB filesystem. For example:

cat /dev/hd0 > /SMBfilesystem/backupfile

I’m thinking that the 2GB size limit for a file might be the cause,
because
that’s the resulting size of the …/backupfile. I tried a couple of
tests…

Files on FAT32 (I assume that is what you mean by SMBFilesystem)
are limited to 4Gigs.

I appended to the …/backupfile with: print “growing the file”
/SMBfilesystem/backupfile. Surprisingly enough, the file grew!?

Earlier, when accessing /dev/hd0, I checked “sin fi” and found that the
“position” read nnnnM/ 2147M. Therefore, I tried “dd” to seek near the
so-called end-of-file: dd if=/dev/hd0 of=/SMBfilesystem/backupfile
ibs=1000k obs=1000k skip=2000. The resulting file was less than 100 MB.

Test results: I can write (append) to a file past 2GB, but I can’t read a
raw disk past 2GB. Hmmmmm.

Could it be Fsys, or Fsys.eide? I’m using LBA mode, which I want.

Thanx in advance,
John Colburn

P.S. Here’s something interesting that I discovered.

In the example above (cat /dev/hd0 > /SMBfilesystem/backupfile), the data
was transferred at a certain speed. If, while this process was running, I
ran a similar process (cat /dev/hd0 > /SMBfilesystem/backupfile.2), the
/SMBfilesystem/backupfile was growing about 10 times faster! When I used
the dd command (above) instead of cat, the speed gain was in the order of
30
times!

4

Thanx for your response Paul. I wanted to back up all partitions,
regardless of type and size.

John.

“Paul Russell” <paul@jenosys.com> wrote in message
news:92vof0$9r9$1@inn.qnx.com…

Why don’t you just Tar&Gzip the whole directory tree?
If you Raw disk copy and the target has some different bad sectors you
might not be pleased with the
result.
-Paul

John Colburn <> jcolburn@city.winnipeg.mb.ca> > wrote in message
news:92vgtp$5n6$> 1@inn.qnx.com> …
I’m trying to make a backup using the raw disk copy method. It doesn’t
seem
to work, and I’m wondering if someone might be able to help (or, at
least
explain why).

I simply try to cat the contents of the first raw disk (6GB) to a file
on a
SMB filesystem. For example:

cat /dev/hd0 > /SMBfilesystem/backupfile

I’m thinking that the 2GB size limit for a file might be the cause,
because
that’s the resulting size of the …/backupfile. I tried a couple of
tests…

I appended to the …/backupfile with: print “growing the file”
/SMBfilesystem/backupfile. Surprisingly enough, the file grew!?

Earlier, when accessing /dev/hd0, I checked “sin fi” and found that the
“position” read nnnnM/ 2147M. Therefore, I tried “dd” to seek near the
so-called end-of-file: dd if=/dev/hd0 of=/SMBfilesystem/backupfile
ibs=1000k obs=1000k skip=2000. The resulting file was less than 100 MB.

Test results: I can write (append) to a file past 2GB, but I can’t read
a
raw disk past 2GB. Hmmmmm.

Could it be Fsys, or Fsys.eide? I’m using LBA mode, which I want.

Thanx in advance,
John Colburn

P.S. Here’s something interesting that I discovered.

In the example above (cat /dev/hd0 > /SMBfilesystem/backupfile), the
data
was transferred at a certain speed. If, while this process was running,
I
ran a similar process (cat /dev/hd0 > /SMBfilesystem/backupfile.2), the
/SMBfilesystem/backupfile was growing about 10 times faster! When I
used
the dd command (above) instead of cat, the speed gain was in the order
of 30
times!

\

5

Thank you for your response, Mario. I expected that the 2GB file size limit
was applicable to all file systems, but I was obviously wrong.

Of course, if I am finally somehow able to read the whole 6GB drive, I would
end up attempting to write to a file of the same size, which is too large.
I’ll have to pipe the data through gzip, then to the file, which should
remain below 4GB.

John.

“Mario Charest” <mcharest@void_zinformatic.com> wrote in message
news:92vp0s$apo$1@nntp.qnx.com…

“John Colburn” <> jcolburn@city.winnipeg.mb.ca> > wrote in message
news:92vgtp$5n6$> 1@inn.qnx.com> …
I’m trying to make a backup using the raw disk copy method. It doesn’t
seem
to work, and I’m wondering if someone might be able to help (or, at
least
explain why).

I simply try to cat the contents of the first raw disk (6GB) to a file
on
a
SMB filesystem. For example:

cat /dev/hd0 > /SMBfilesystem/backupfile

I’m thinking that the 2GB size limit for a file might be the cause,
because
that’s the resulting size of the …/backupfile. I tried a couple of
tests…


Files on FAT32 (I assume that is what you mean by SMBFilesystem)
are limited to 4Gigs.

I appended to the …/backupfile with: print “growing the file”
/SMBfilesystem/backupfile. Surprisingly enough, the file grew!?

Earlier, when accessing /dev/hd0, I checked “sin fi” and found that the
“position” read nnnnM/ 2147M. Therefore, I tried “dd” to seek near the
so-called end-of-file: dd if=/dev/hd0 of=/SMBfilesystem/backupfile
ibs=1000k obs=1000k skip=2000. The resulting file was less than 100 MB.

Test results: I can write (append) to a file past 2GB, but I can’t read
a
raw disk past 2GB. Hmmmmm.

Could it be Fsys, or Fsys.eide? I’m using LBA mode, which I want.

Thanx in advance,
John Colburn

P.S. Here’s something interesting that I discovered.

In the example above (cat /dev/hd0 > /SMBfilesystem/backupfile), the
data
was transferred at a certain speed. If, while this process was running,
I
ran a similar process (cat /dev/hd0 > /SMBfilesystem/backupfile.2), the
/SMBfilesystem/backupfile was growing about 10 times faster! When I
used
the dd command (above) instead of cat, the speed gain was in the order
of
30
times!

\