Re: Tape Support for Informix & Backups

My comments interspersed: riedyw@my-dejanews.com wrote: > > ONTAPE > We are currently using this method. Simple to implement. Requires manual > intervention (prompted for options and changing tapes). Can only write to > tape. Not true. You can write to disk as well. It's not supported, but not because it doesn't work (I can assure you it does), but because it's easy to overwrite. Also, your operating system may have limites on the size of individual files. > > DBEXPORT Gives the option of exporting to tape or to disk. Exports the > schema and data separately. Format of data is UNLOAD file format (pipe > delimited). Exported files being sent to disk are limited to 2 GB. Locks > the full database (i.e. no user activity). Exported data is in text format > and can be loaded with DBIMPORT or via LOAD. Level of granularity: database > by default, table if exported to disk. Can be extraordinarily slow to re-import. I've just this week dbimported a 10GByte database on a development database; it took 40 hours! > ONUNLOAD > Exports data in binary file format, need to reload with ONLOAD. Level of > granularity: dbspace An extremely irritating bug in v7.13 -> v7.20 means that an onunload may fail with the useful message "error reading buffer" - hence the 40-hour import mentioned above. > ONARCHIVE > Exports data in binary file format, need to reload with ONARCHIVE. Level of > granularity: dbspace A complete pile of crap. Don't give it a moment's thought. IMHO. > CONCERNS > > > All of these backup medias are slow and small in comparison to DLT. > Currently our backups take a LONG time due to the slow transfer rate > (relative to DLT) and the need to flip the tape. What is Informix's plan to > support DLT? I've had no problems using DLT on v7.13 on Solaris with ontape. onarchive didn't work with DLT. I believe from other postings that many other Informix versions/operating systems are OK with DLT. Neil Truby aracnet Ltd. Weybridge, UK