Monitoring Tape Drives consumption

[nibble]

hi guys,
kindly help me with this scenario.

we're currently running a system which randomly dumps its log to a DDS3 tape drive. currently, we only change the tape once it is full as indicated by the system. once its full, the system stops running which we have to mount a new tape to continue. to avoid the sytem from pausing, we want to replace the tape if it has already written 70%-90% of its full capacity or before it fully consumes the capacity.

is there any way that can monitor the capacity of a tape that has already been written/used up?

we're running 11.0 UX

[Leif Halvarsson_2]

Hi,

Sorry, it is not possible to "query" the drive about the tape used or how much data written. The only way is if the application monitors the data dumped to the drive. If it is a script, it is perhaps possible to modify it.

[Massimo Bianchi]

Hi,
AFAIK there is no such tool, you must write your own script.


First: what is written on the tape, and in which format ?
This is essential for further help.

Depending on whether is a tar, cpio, dd, brarchive, ontape -l, pax we can decide for different solution of cross-checking.


Second: if logs are written to tape, i suspect that they are also deleted from disk. Then, you can compute how much did you write reading how much free space you have on disk.


Third: the calculation is, in any case, not very easy, because if you are using HW compression there is no a 1 to 1 ratio between mb written and tape used.


Fourth: would it be easier to change the tape on a regular basis, say at 12:00 ? Or twice a day, so you are always sure that there is space left.

Massimo

[nibble]

its actualy a "ontape -c" (informix) command w/c dumps the logical logs to the tape.

the idead of changing the tape regularly also came out, but i was jes wondering if it could be possible that way..

thanks..

[Massimo Bianchi]

OK. we are a step closer.

You know how many logs go into one tape, right?
Or you can desume it, checking the first time you change the tape and taking note.

THe size of informix log is static and fixed, even if i do not remember wich parameter is... LOGSIZE maybe?


Then, each time you download the log, you can have informix tell you the number and calcute how may tapes are left.


Does it sound to you ?

Massimo

[Tim Adamson_1]

I think there are several posts concerning this issue. I responded in one of the others. I will repeat the information here.

Check the ddsinfo utility at the following link. It is for 10.10 but may work with 11.0

http://hpux.connect.org.uk/hppd/hpux/Sysadmin/ddsinfo-1.3/


Tim

[Christopher Davis]

Actually, I was looking for the same information from my tape drives. I have C3600 series workstations, running 11.00. I have DLT 8000 tape drives. I spotted this little application, I installed it, and it seems to work well. You MUST run it under a SU account (or equivalent), and it was necessary for me to save it in /usr/bin under a new name (e.g. tape_info). I also had to run the "ioscan -funC tape" command, in order to correctly identify the device. Look at the following FTP site on itrc site. Be sure to install the tapeinfo.1100 version. Also be sure to read the README file.

ftp://contrib:9unsupp8@hprc.external.hp.com/sysadmin/programs/tapeinfo/

[Rodney Hills]

Could you spring for an additional tape drive and when the first fills up have it auto swap (which utilities like fbackup can do) to the second drive?

That way you don't miss a beat in your log files.

My 2 cents

-- Rod Hills