Conference decwet::advfs_support

1000.0. "vdump|vrestore on TZK11 QIC-150 cartridges?" by MUNICH::DANNER () Thu Feb 06 1997 05:59

config:  reproducable on dU V3.2c thru V4.0a
         tz1 at scsi0 bus 0 target 1 lun 0 (DEC_TZK11 (C) DEC 00A2)

Ref. page: tz(7) about TZK11
----------------------------------
With QIC-format 24/120/150 tapes, all read and write operations must
be in multiples of the block size because record boundaries are not
preserved.  
QIC-150   rmt?m            fixed 512    150MB      DC6150      Read/Write
QIC-2G    rmt?h            variable     2G         DC9000      Read/Write

Problem: Although vdump(8) does write to TZK11 QIC-150MB cartridges w/o
         reporting any errors vrestore fails to read it back in.

         vdump|vrestore fails only with 150MB cartridges using /dev/rmt#m.

         Writing to >=320MB cartrigdes using /dev/rmt#h works problemfree.
         Also dump|restore, cpio and tar perform successfully with all
         (150MB /320MB/512MB/2GB) cartridges on TZK11 devices.

I guess the problem with has to do with the record format
(fixed block versus variable block) vdump is using.

Could someone please shed some light on this.
Should vdump|vrestore work with TZK11 using QIC-150MB cartridges?

Docs and Ref. pages do not tell that it's unsupported.

Tried vdump with diferent blocksizes ( -b=[1|2|8|10|16|64 ).

errors reported by vrestore:
----------------------------

1) vrestore: empty save-set
   DECthreads Last Chance handler: thread 1 exiting on status exception 0x177db005
   Exception: Invalid memory address (dce / thd)
   vrestore: Date of the vdump save-set: Tue Jan 14 19:00:23 1997
   vrestore: nothing will be restored

2) vdump -0f /dev/rmt3m /  # same with -b 10
   vrestore -tf /dev/rmt3m
   vrestore: Date of the vdump save-set: Thu Feb  6 10:50:29 1997
   vrestore: unable to restore block <1>; corrupt block

BLOCK HEADER
 block size : 3764601
 flags      :
 volume set : 0
 volume sets: 32769
 volume num : 0
 block num  : 166
 header CRC : 0x0000
 block CRC  : 0x0018
 xor blocks : 5
 xor blk num: 29812

...and so forth...

vrestore: empty save-set
vrestore: nothing will be restored
Tape is fixed block and byte count is not a multiple of block size.
Blocking factor of tape is 512

3) vdump -0f /dev/rmt3m -b 1 /  #same error with -b 8
   vrestore -tf /dev/rmt3m
   vrestore: Date of the vdump save-set: Thu Feb  6 11:08:45 1997
   vrestore: ino_tbl_add_dir(210); parent ino not found


any comments are highly appreciated
thanks in advance
                     Reinhold
                     CSC  Muc