Thanks for all the answers... very informative and now I am confident that what the client is asking is too much.
The application is a custom Ad Server (think adSense, iAd, etc) for mobiles we implemented in Japan. And as some know the mobile market in Japan is huge. We have three clients and between them we get 300,000,000 (300 million) hits per month. The image data changes several times a day but the database and log files change hundreds of times per second. Each record/line in the DB and logs represents lots of money for advertisers and publishers that cannot be lost. Our system is hosted in a cloud and they handle virtual machine snapshots (they say) but I cannot tell how effective or good these are. For example I understand these snapshots do not guarantee that the DB is in a stable because they cannot flush the DB memory during the snapshot and the same may be true for logs. As many said this 15 min requirement is too much for any backup solution and instead I will go with high availability options like redundant DBs (slaves) and remote logging (rsyslog). thanks for all the answers, very helpful.... regards, Horacio
