ON_bar Backup

We are running IDS7.3 on an IBM RS6000(OS AIX4.3). We are backing up about 35GB nightly using the onbar(ism). The tape drive is 8mm SONY AIT2. The backup is currently taking more than 7 hours and most nights it doesn't finish before the next day's business begins.ON_bar takes most time to write tape's EOF.Tape block size is set to 64k. What's the best solution?

Hi, Maybe bug 101062, arc_very_old_page. You can check this with "onstat -g ath", get the session_id of the ontape process, and then run "onstat -g stk <session_id>" and look for arc_very_old_space Solution that worked on our system: Add "CCFLAGS to 0x400000" in your onconfig. Alex vampirewp wrote: >We are running IDS7.3 on an IBM RS6000(OS AIX4.3). We are backing up >about 35GB nightly using the onbar(ism). The tape drive is 8mm SONY >AIT2. The backup is currently taking more than 7 hours and most nights >it doesn't finish before the next day's business begins.ON_bar takes >most time to write tape's EOF.Tape block size is set to 64k. > >What's the best solution? > >

vampirewp@tom.com (vampirewp) writes: > We are running IDS7.3 on an IBM RS6000(OS AIX4.3). We are backing up > about 35GB nightly using the onbar(ism). The tape drive is 8mm SONY > AIT2. The backup is currently taking more than 7 hours and most nights > it doesn't finish before the next day's business begins.ON_bar takes > most time to write tape's EOF.Tape block size is set to 64k. > > What's the best solution? Try to make the tape stream. I've been looking for ages for info on my Sony SDT-9000 drives for the optimum block size for streaming uncompressed to DDS3 tapes, but have never been able to find that spec. -- Forte International, P.O. Box 1412, Ridgecrest, CA 93556-1412 Ronald Cole <ronald@forte-intl.com> Phone: (760) 499-9142 President, CEO Fax: (760) 499-9152 My GPG fingerprint: C3AF 4BE9 BEA6 F1C2 B084 4A88 8851 E6C8 69E3 B00B

Increase the block size would be a good starting point, I'd suspect you are not driving the tape hard enough vampirewp wrote: > > We are running IDS7.3 on an IBM RS6000(OS AIX4.3). We are backing up > about 35GB nightly using the onbar(ism). The tape drive is 8mm SONY > AIT2. The backup is currently taking more than 7 hours and most nights > it doesn't finish before the next day's business begins.ON_bar takes > most time to write tape's EOF.Tape block size is set to 64k. > > What's the best solution? -- Paul Watson # Oninit Ltd # Growing old is mandatory Tel: +44 1436 672201 # Growing up is optional Fax: +44 1436 678693 # Mob: +44 7818 003457 # www.oninit.com #

vampirewp <vampirewp@tom.com> wrote: > > We are running IDS7.3 on an IBM RS6000(OS AIX4.3). We are backing up > about 35GB nightly using the onbar(ism). The tape drive is 8mm SONY > AIT2. The backup is currently taking more than 7 hours and most nights > it doesn't finish before the next day's business begins.ON_bar takes > most time to write tape's EOF.Tape block size is set to 64k. > > What's the best solution? First of all, if it is indeed ISM, then I wonder, how do you see the tape block size is 64k. Do you mean the parameter in the onconfig (which is not used by ONBAR) or do you mean the blocksize as shown in the ISM; you have to check in the ISM that the type of the device is '8mm AIT-2'. If you use ONBAR, TAPEBLK etc. are irrelevant. What's the speed of your disks ? You can measure this using the 'uasm' utility in /opt/informix/bin. time /opt/informix/bin/uasm -s /opt > /dev/null will backup to /dev/null the /opt filesystem. (if you know the size of /opt, then you can figure out how many MB/s the disk can generate). Is the ISM running on the same machine, or do you go over the network ? If you go over the ethernet, you should be able to backup 35GB in somewhat less than two hours (100mbit). Is the ethernet giving problems ? (run "entstat" on the interfaces). Assuming you don't go over the ethernet, did you run an "errpt" to see whether there are errors logged at the tape driver level ? If you have errors, check whether upgrading the software AIX device driver helps. It would be interesting to see what kind of errors (I/O errors, tape rewinds, will enormeously slow down the backup of course).