since last week My Full Backup Increased dramatically .before last week the time is about 3 hour and now the time is about 6 hour.in addition some query take long time to run. (not all the query).I thought the problem is relate to disk I/o. and I try to copy/past some files from one hard drive to another and it is done very quickly.(3 giga byte in 4-5 sec).and all the query work with temp table slow down. is it relate to I/o or what..?
i found the solution.the network admin defrag Disk that cause Database fragmentation.by defrag databases the problem is gone