[Info-vax] ZIP, UNZIP and BACKUP/COMPARE reporting %BACKUP-E-VERIFYERR

Hein, Nashua NH heinvandenheuvel at gmail.com
Thu Sep 10 02:39:52 EDT 2009


On Sep 9, 3:42 am, Volker Halle <volker_ha... at hotmail.com> wrote:
> I came across this problem, when testing a networker restore operation
> on OpenVMS. How do they say: "don't test your backups, test your
> restores" ;-)
>
> If you create a simple sequential variable-length file, ZIP it and
> UNZIP it, DIFFERENCES will be happy. But BACKUP/COMPARE will report
> %BACKUP-E-VERIFYERR for the EOF block in those files.
>
> A more detailled look (using DUMP) shows, that there is some data
> after the EOF byte, which is not being preserved by ZIP/UNZIP (and
> Networker for that matter), whereas an OpenVMS BACKUP (or an ABC/
> Tivoli) backup/restore preserves this data.

Actually... IMHO it is BACKUP which is more broken and inconsistent.

Yeah, sure it copied the bytes after FFB (First Free Byte).
But it fails to the blocks after EBK (End Of File Block) !

I have requested BACK/IGNORE=EOF to no avail.
IMHO that's a serious omision. EOF if up to my personal
interpretation!

$ZIP "-VV" on the other hand does the right thing.
$ZIP -vv btw does a fun thing! I like it ! (That's two vees, not a
double you :-)

Some parts of a reproducer below....

Hein.

$ cre tmp.txt
VMS
$ dump tmp.txt
:
 00000000 00000000 00000000 00000000 00000000 00000000 FFFF0053
4D560003
..VMS........................... 000000
:
$ set file/attr=ebk=3 tmp.txt
$ set file/att=(rfm=fix,lrl=512,mrs=512) tmp.txt
$ open/read/write tmp tmp.txt
$ read tmp rec
$ show symb rec
  REC = "..VMS........
$ read tmp rec
$ show symb rec
  REC = ".......................
$ rec = f$fao("!512AS","test")
$ write/upda/sym tmp rec
$ close tmp
$ dump tmp.txt
Virtual block number 1 (00000001), 512 (0200) bytes
 00000000 00000000 00000000 00000000 00000000 00000000 FFFF0053
4D560003
..VMS........................... 000000
:
Virtual block number 2 (00000002), 512 (0200) bytes
 20202020 20202020 20202020 20202020 20202020 20202020 20202020
74736574
test                             000000
:
$ set file/att=ebk=1 tmp.txt
$ set file/attr=(rfm=var) tmp.txt
$ type tmp.txt
VMS
$ dump...
$ back tmp.txt copy.txt ; set file/attr=ebk=3 copy.txt; dump ---> no
more "test"
$ zip "-VV" tmp tmp.txt; delete tmp.txt; unzip tmp; set file/
attr=ebk=3 copy.txt; dump ---> "test"

fwiw,
Hein.






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