Re: Mirroring

cburton@gte.net wrote: > > I am currently on 7.11.UC1 on HP-UX 9.04 > > To experiment (before implementing), I created a mirror of the > root_dbs. Both the root and the mirror are seperate logical (and > physical) devices. The links to the devices were created in > /usr/informix/dev. t_root_dbs and t_root_mir > > After recovery of the root had taken place (watched the log), I did a > level 0 to make sure everything was in sync. Then I deleted the > symbolic link in /usr/informix/dev to t_root_dbs so it would be on the > mirror. I then waited for onstat -d or the log to report the root_dbs > was down. I then did update stats on a table. Dropped and recreated > another table. Created a stored procedure. (All should of had > activity on the root_dbs space). onstat -d showed reads and writes > from the now (supposedly missing) root_dbs. Again I waited. Two > check points; another hour. NO MESSAGES that I now have a (simulated) > device error. I called INFORMIX help, and their answer was that I had > to bounce the server (at least once a week, according to their > guidelines) in order to find a problem. If I have a 24x7 system, & > cannot bounce the server, the mirroring is a moot point. > > Someone please tell me this is wrong. > > TIA > > Chris Hi Chris, I think you should contact your UNIX support or just read the manual entry of "rm". It's only removed from your directory, but it's still there. A file will not be deleted as long as a process has an open connection (read/write) to this file. It's very difficult to "simulate" a device error. If you want to simulate a device error you must force the UNIX calls (read/write/lseek/tell) to return the value -1. Otherwise it's nearly impossible, because Informix will open it's chunks only at startup time. Maybe it's possible to switch off your disks, or make use of a floppy disk to simulate the device error. Have a nice day, Stefan