Here is a example of a real world crash: disk failure, we can not get a single bit from it. Fortunately we have a backup on a 4mm tape. So we have level 0 backup and a logical logs on it. So we first install system, informix and ISM and try to do a cold restore. First, we must restore a ISM database from tape. Then we try to do a physical restore with onbar -r -w -p. But we get a error message: Backup object does not exist in Storage Manager. It seems that the ixbar file is missing. So how we can do a restore?
Current configuration is:
Informix 7.3 TC7 and
Legato ISM 1.0
I use informix on Solaris + Soltice Backup but I think it's the same way,
ixbar file , it like a notepad that note for database backed up data so if database backup some kind of data that's in the tape it can relate with ixbar file ONLY SOME LINE in the file , so you must find and choose the line of ixbar file to relate with your tape , I recommend you open and edit you ixbar file choose the line that it backed up data in to the tape , the exact sequance line of the ixbar file
You can use onbar command to physical + logical resore : onbar -r
Only physical restore : onbar -p
but you must run logical restore after physical restore : onbar -r -l
if you want specify log number which are ending restore : onbar -r -l -n <the-name-of-log>
and which <the-name-of-log> do you want to restore ? ... you can see in your ixbar file
I beleive that the main problem here is how to restore the ixbar file from information, which resides on tape. If this can not be done, then it is essential to backup this file on a regular basis to another network drive or other backup media, or 4mm tape with data is useless, because cold restore can not be done.