Re: Automatic backup of logical logs v6

Neil Truby — Sun, 05 Oct 1997 09:55:19 -0700 — source: @@NL@@> Having had a problem with logical logs filling up under v6 I@@NL@@> decided to try the automatic backup option. Consulting the manual@@NL@@> indicates that a dedicated terminal will be required for this@@NL@@> purpose since prompts for additional tapes will be made at some@@NL@@> point. I was wondering if it were possible to backup the logs to@@NL@@> disc (seperate from the disc on which the database resides). The@@NL@@> backed up logs on disc could then be archived to tape each@@NL@@> evening and removed from disc - thus maintaining sufficient free@@NL@@> space (the database is v low on acitivity so does not consume log@@NL@@> space hand over fist). Doing things this way would negate the@@NL@@> need to dedicate a terminal to the process since (in theory) disc@@NL@@> space would never be exhausted.@@NL@@@@NL@@Many sites, including my own, do this. You should use the continuous@@NL@@back-up option (tbtape -c). There are one or two pitfalls to avoid:@@NL@@the output file (defined by LTAPEDEV in your TBCONFIG) must pre-exist@@NL@@with the appropriate ownership and permissions; depending upon the level@@NL@@of activity this file can grow to a significant size; you must kill the@@NL@@tbtape -c each night just before you back-up the file to disk then@@NL@@re-create it before you start the new tbtape -c; if you automate this@@NL@@you must take care at server boot-up becuase a new invocation of tbtape@@NL@@-c will over-write your existing log back-up; you may get end-of-file@@NL@@errors when rolling forward logs backed up to disk (although the@@NL@@roll-forward will still be valid).@@NL@@@@NL@@This point about it being easy to over-write an existing back-up is the@@NL@@strongest argument against this techinique IMVHO.@@NL@@@@NL@@Neil Truby@@NL@@Chase Manhattan Bank@@NL@@Bournemouth, UK@@NL@@@@NL@@neil.truby@chase.com