RE: Archive and restore by named pipe

We had the same problem when we moved to 7 engine on our sco boxes. Our archives write to a compressed file via named pipe just fine, but will not restore the same way is they did under 5. Our solution is to decompress the archive to a spare tape, (we are using the tape for file system backups and swapping out at night to do an archive as well is not practical.) then recover from that tape. This is a bit inelegant, but it does work and needing to recover from archive is quite rare. > ---------------------- > Robert K. Lofstrand 806.351.2300 x3650 > Informix Database Specialist lofstrr@hastings-ent.com > Hastings Entertainment Inc. http://www.gohastings.com > > > -----Original Message----- > From: David Kosenko [SMTP:dkosenko@home.com] > Sent: Sunday, January 09, 2000 3:55 PM > To: informix-list@iiug.org > Subject: Re: Archive and restore by named pipe > > The problem is in the way that ontape reads the backup media. It first > reads > the header off the media, then closes the file descriptor, expecting the > media > to "rewind" (this is why you cannot usually use no-rewind devices with > ontape). > It then rereads it from the beginning for the physical restore. Because > your > pipe cannot be "rewound", after it closes the fd and reopens it, it reads > data > that is not (now) a valid header, so the restore fails. > > Theoretically, if you could send two copies of the header to the pipe > during the > restore, it should work. Offhand, I don't know how long the header is. > You > could probably do a dd & od and figure out how many bytes make up the > header and > then put a kludge in your script to send the header twice. > > Dave > > Also sprach Juerg Schaer <jsc@imtf.ch> : > > :Hello > : > :I'm looking for a solution to avoid the use of a tape drive for > :archiving Informix by ontape. > :I have tested, that only archives less than 2GB can be used without > :problems, but my archive is about 3 GB and it's growing. > :I have tested the way by using a named pipe as a TAPEDEV. > : > :Tape section of onconfig. > :TAPEDEV /tmp/ontape.nmp # Tape device path > :TAPEBLK 1024 # Tape block size (Kbytes) > :TAPESIZE 4096000 > : > :my archive script: > :#!/bin/ksh > :PIPE=/tmp/ontape.nmp > :FN=/dbms/informix/ontape.`date +"%Y%m%d"` > :MAXSIZE=500m > :export MAXSIZE PIPE FN > : > :rm $PIPE > :mknod $PIPE p > : > :( /usr/local/bin/gzip < $PIPE ) | split -b $MAXSIZE - $FN. & > : > :echo "\\ny" | ontape -s -L 0 >> /tmp/nmpbkup.log > :# end of archive script > : > :my restore script: > :#!/bin/ksh > :PIPE=/tmp/ontape.nmp > :FN=/dbms/informix/ontape.`date +"%Y%m%d"` > :export PIPE FN > : > :cat `echo $FN.* | sort` | /usr/local/bin/gunzip > $PIPE & > :echo "\\ny\\nn\\nn\\n" | ontape -r > :# end of restore script > : > :But always the physical restore failed by restoring from named pipe !!! > :The archive seems to be OK. > :By unzipping instead of $PIPE into a file, the restore is OK. > :It seems to be a problem with TAPEBLK ... > : > :I am using Informix Dynamic Server Version 7.30.UC8 for AIX 4.2.1 > : > :Can anybody help me ? > : > :