How to duplex archivelog with just one tape drive ?

Question

The subject explains everything.
My company has just one tape drive, however I'm afraid to lose the only tape that contains just 1 copy of archivelog.
I've my own scripts to try simulate duplexing, but I'd like to know if someone has a problem like me and what do you do to workaround it.
Thank you very much
Marcelo Sinni

Answer 1

Yes, I do. I've three scripts simulating trying to obtain 3 copies of the same archivelog:
RMAN> print script ArchiveF1;
printing stored script: ArchiveF1
{allocate channel c1 type 'SBT_TAPE';
send 'OB_MEDIA_FAMILY Oradell01-Archives-F1-A';
sql "alter system archive log stop";
sql "alter system switch logfile";
sql "alter system switch logfile";
backup
format 'F1_%U.arch'
(archivelog until time "TRUNC(SYSDATE+1,'DD')" NOT BACKED UP 3 TIMES);
RMAN> print script ArchiveF2;
printing stored script: ArchiveF2
{allocate channel c1 type 'SBT_TAPE';
send 'OB_MEDIA_FAMILY Oradell01-Archives-F2-A';
backup
format 'F2_%U.arch'
(archivelog until time "TRUNC(SYSDATE+1,'DD')" NOT BACKED UP 3 TIMES);
RMAN> print script ArchiveF3;
printing stored script: ArchiveF3
{allocate channel c1 type 'SBT_TAPE';
send 'OB_MEDIA_FAMILY Oradell01-Archives-F3-A';
backup
format 'F3_%U.arch'
(archivelog until time "TRUNC(SYSDATE+1,'DD')" NOT BACKED UP 3 TIMES delete all input);
sql "alter system archive log start";
In this script ArchiveF1, I stop ARCH process and afterwards execute two log switch (since I've three redo logs and whereas the DB is in archivelog mode, the third log switch will not happen, so I eliminate the possibility to occur a log switch during archivelog backup thence I have three identical copies of archivelogs in three separated tapes.)
ArchiveF3 enable archivelog again.
To me it has worked fine but, I'd like another opinions about that.
Thanks