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On Wednesday 08 Oct 2003 12:56 am, Neil Williams wrote: > > > Thanks for the suggestions. With the 10 - 20 minute cron job - would that > > copy open files? We have a large number of transactions every day (I work > > Depends on what process has opened the file and how it has locked the file. > cron is just the daemon that executes the script/program etc. Whether the > file can be copied is up to the permissions/setup of the script/program > called by cron. If it's a bash script, it would probably come down to whose > crontab you use to install the cron task. I have no idea how to test this - the program is provided by our IT suppliers and it's workings are a mystery to me. And to them sometimes it seems. > > mis-quote Murphy). It is almost certain that there would be open files at > > the time of the cron job. > > But each individual file wouldn't be open all the time, so cron / your > script might get a chance to copy when the file is closed whilst the main > process moves on to another task. e.g. MySQL only locks the tables when an > insert or update is in progress (and even that's configurable) - select > queries can wait until other processes are done. > > What size files are you thinking would be open? > What type? > How many? Absolutely no idea. This is just conjecture at the moment - i.e. is this somewhere in the realms of possibility. > Isn't this getting into areas where RAID would become a practical solution? > I have little experience of RAID but I believe it could give you a mirror > type copy on the first server (which would deal with the immediacy of the > data) and the backup server could copy that freely. We already have RAID on our server, but it is RAID 5 which is not strictly a copy - more an amalgamation over the three disks (+1 hot spare). Given the option I would change/upgrade to RAID 10 for the read performance gain at least. Thanks again, Mark -- For information on Newquay, Cornwall, and the surrounding area: http://www.Newquay-Plus.co.uk -- The Mailing List for the Devon & Cornwall LUG Mail majordomo@xxxxxxxxxxxx with "unsubscribe list" in the message body to unsubscribe.