Radoslaw Skorupka wrote: >To complement and clarify: when using physical tapes (* >see below) your RPO and RTO may be 36 hours or zero.
No, your RPO certainly won't be zero. A backup is a (hopefully useful) representation of data as it existed historically, at some particular past moment(s) in time. It takes some amount of time to run a backup -- let's call that "minutes or longer" for working purposes. Backups run at periodic intervals -- let's call that "hourly or less often" for working purposes. Your backups, without something else, facilitate a best case RPO that's as long/big as the maximum (worst case) time elapsed since the start of your last good backup. That practically always(*) means a RPO of "a couple hours or more." A long/big RPO usually holds RTO back too, but there are a few rare exceptions. On the other hand, it's quite possible to have a long/big RTO with a RPO of zero. (*) Why not "always"? Exotic, contrived exceptions might be possible, such as custom software that synchronizes writes directly to local and remote tape. - - - - - - - - - - Timothy Sipples I.T. Architect Executive Digital Asset & Other Industry Solutions IBM Z & LinuxONE - - - - - - - - - - E-Mail: sipp...@sg.ibm.com Mobile/SMS: +65 8526 7454 or +1 213 222 6397 or +372 5322 0545 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
