tar backup Issue

[prasanna wijeratna]

we are running HP-UX 11 on N class server and needs to transfer some data to Sco unix system
I used following command to get backup
# tar cvf /dev/rmt/0m /home/somedir
This is succesfull but when you try to restore in Sco unix U get some checksum error message
Is there any special switch to be used with tar when U get backup for compatibility ?

[Stuart Browne]

What's the default block size used for tapes on the HP-UX machine?

On the SCO side, what do the following commands return:

tape getblk /dev/rStp0
dtype /dev/rStp0

If the blocking factor is off, you can try changing the block size on the SCO side (using 'tape -a setblk /dev/rStp0'), or use 'dd if=/dev/rStp0 bs= | tar xvf -' to restore using the modified block size.

Unfortunately, I don't have a HP-UX tar file handy to try on my OSR machines here, sorry.

(NOTE: Actually, I should have asked earlier. What release of SCO are you using? Use 'uname -X', and show the 'Release' line. The commands here should work on most releases however).

[Sunil Sharma_1]

Whenever you do cross platform data transfer, always specifie block size with tar with -b option. In Hp default is 20 so you can try same in SCO

Sunil

[Franky_1]

Hi,

if there's a problem in that way then it's almost always because there are different block sizes
So you should use tar with the "-b" option

Regards

Franky

[prasanna wijeratna]

Hey thanks for the informatin I am not very familier with SCO unix please find belw some information from SCO side

#
# uname -X

System = SCO_SV
Node = isddev
Release = 3.2v5.0.5
KernelID = 98/07/02
Machine = i80386
BusType = ISA
Serial = 4EB012127
Users = 30-user
OEM# = 0
Origin# = 1
NumCPU = 1

# tar
Usage: tar -{txruc}[0-9vfbkelmnopwAFLTP] [tapefile] [blocksize] [tapesize] files
...
Key Device Block Size(K) Tape
0 /dev/rfd048ds9 18 360 No
1 /dev/rfd148ds9 18 360 No
2 /dev/rfd096ds15 10 1200 No
3 /dev/rfd196ds15 10 1200 No
4 /dev/rfd0135ds9 18 720 No
5 /dev/rfd1135ds9 18 720 No
6 /dev/rfd0135ds18 18 1440 No
7 /dev/rfd1135ds18 18 1440 No
8 /dev/rct0 20 0 Yes
9 /dev/rctmini 20 0 Yes
10 /dev/rdsk/fp03d 18 720 No
11 /dev/rdsk/fp03h 18 1440 No
12 /dev/rdsk/fp03v21 10 20330 No
# tape getblk /dev/rct0
tape: can't open '/dev/rct0': No such device or address
# dtype /dev/rct0
/dev/rct0 No such device or address

# tape getblk /dev/rctmini
tape: can't open '/dev/rctmini': No such file or directory
# dtype /dev/rctmini
/dev/rctmini No such file or directory

[Franky_1]

Hi,

i don't know the block_size of SCO, but maybe there's a similar command like in HPUX "fstyp -v " and then you'll have to use this one for tar

HTH

Franky

[Franky_1]

Hi,

please assign points accordingly so that one can see if any of the answers helped you out

Regards

Franky

[Heiner E. Lennackers]

HP uses by default a blocksize of 20 (10KBytes per Block). You can try to use this knowledge on the SCO UNIX machine by trying to extract it with:

tar xvbf 20