Re: failing & corrupt hdisks & mirror... restore VG's from tape?

Here are some of my notes on analysing the contents of a mksysb tape.
You may find them a good starting point for looking at your savevg
tape. The mksysb produces several tape files and if you skip past the
header ones to the actual data you can read the data with a simple
restore command. The same is probably true for your savevg tape, so
if you can recognised the filenames for the VG that you're looking for
you may be able to extract them manually if you can't get the restvg
to work.

To read and identify the block size on a tape use
lsattr -El rmt0 # Note the existing block size, say ???
chdev -l rmt0 -a block_size=0 # Allow variable block size to be used
dd if=/dev/rmt0 of=/tmp/block bs=128k count=1
wc -c /tmp/block # Display the size of the first block on the tape
file /tmp/block # Display the type of the data on the tape
# A mksysb tape will have "data or International Language text" as
the first file type
rm /tmp/block
chdev -l rmt0 -a block_size=??? # Restore the original block size
To check if a tape is in mksysb format use
lsattr -El rmt0 # Note the existing block size, say ???
chdev -l rmt0 -a block_size=512 # Use block size of 512 bytes
mt fsf 2
dd if=/dev/rmt0 count=1
# A mksysb tape will have "Dummy tape TOC" as the third file data
chdev -l rmt0 -a block_size=??? # Restore the original block size
To determine the time that a mksysb tape was written use
lsattr -El rmt0 # Note the existing block size, say ???
chdev -l rmt0 -a block_size=512 # Use block size of 512 bytes
mt fsf 1
restore -tqf /dev/rmt0.1 # Display the tape file's header including
timestamp
mt rewind # Rewind the tape ("restore -tqf /dev/rmt0" fails)
chdev -l rmt0 -a block_size=??? # Restore the original block size

.

Relevant Pages

  • 7020-0U0/3440-001 tape troubles......
    ... The above tape drive is causing me a bit of concern. ... To install the mksysb image you will need to boot your ... is the same each time I make a mksysb tape. ...
    (comp.sys.ibm.ps2.hardware)
  • Re: Question on mksysb/restore?
    ... the tape format. ... Then use the smit command menu. ... > I have a PowerPC and it doesn't recognize my mksysb tape as bootable. ... > Therefore, after I boot up, and am logged in as root. ...
    (comp.unix.aix)
  • Re: 7020-0U0/3440-001 tape troubles......
    ... boot with an AIX 4.3.3 installation cd and restor from the tape. ... I think I will address the issue of a fix first to see if I can get it ... I ran created a mksysb tape with the basic AIX 4.3.3 installed....and ...
    (comp.sys.ibm.ps2.hardware)
  • Re: Calling Gereon Wenzel.....
    ... If Gereon doesn't have anything suitable, I could supply you with another AIX 3.2.5 MKSYSB tape from one of my 3.2.5 systems. ...
    (comp.sys.ibm.ps2.hardware)
  • Re: Dump
    ... So backup goes like this: ... To restore, you have to skip the tape to the correct position (read up on mt fsf). ...
    (freebsd-questions)