Technical data

Using BACKUP
11.18 Ensuring Data Integrity
11.18.4 /LOG Qualifier
Use the /LOG qualifier to the BACKUP command to display the file specification
of the files that BACKUP processes during a backup operation. For example, if
you are copying files in a directory, you can use the /LOG qualifier to display the
file specification of each file copied:
$ BACKUP/LOG
_From: WORK3:[OCONNELL]*.*
_To: WORK1:[OCONNELL.SCRATCH]*.*
%BACKUP-S-CREDIR, created WORK1:[OCONNELL.SCRATCH.COM]
%BACKUP-S-CREATED, created WORK1:[OCONNELL.SCRATCH]DECW$MAIL.DAT;2
%BACKUP-S-CREATED, created WORK1:[OCONNELL.SCRATCH]DECW$SM.LOG;42
%BACKUP-S-CREATED, created WORK1:[OCONNELL.SCRATCH]DECW$SM.LOG;41
.
.
.
11.18.5 /VERIFY Qualifier
Use the /VERIFY qualifier to cause BACKUP to compare the contents of the input
and output specifiers after a save, restore, or copy operation. When BACKUP is
executing the verification pass, it displays the following message:
%BACKUP-I-STARTVERIFY, starting verification pass
If BACKUP finds differences between the input and output files, it issues an error
message.
Compaq recommends that you use the /VERIFY qualifier. Although it increases
processing time, it also improves data integrity.
Backing Up a Save Set Twice Using /VERIFY Qualifier
The problem described in this section applies to TZ87 and TZ88 tape drives and
to TZ89 tape drives. If you mount a tape /FOREIGN and then back up files to a
save set twice, the second save set reports errors under the following conditions:
• The two save sets have the same name.
• You use the /VERIFY qualifier with the BACKUP command.
• The second BACKUP command has a /BLOCKSIZE of less than 4096 bytes
(8*512).
• The save set is not sufficiently large, for example:
For BACKUP /BLOCKSIZE= The Files Must Total at Least
4000 6300
1
blocks
3580 5400
1
blocks
1
Rounded to nearest hundred
Error messages similar to the following ones are displayed:
%BACKUP-I-STARTVERIFY, starting verification pass
%BACKUP-E-READERR, error reading MKB300:[]SET.SAV;
-SYSTEM-W-DATAOVERUN, data overrun
%BACKUP-E-INVBLKSIZE, invalid block size in save set
%BACKUP-E-INVRECSIZ, invalid record size in save set
%BACKUP-F-READERRS, excessive error rate reading MKB300:[]SET.SAV;
-SYSTEM-W-DATAOVERUN, data overrun
Using BACKUP 11–67