Reading the root cause it is totally acceptable as a flaw caused by OS improvements (Redhat IBM microsoft) out of control of SAS. Improvements sometimes has backfiring effects as in this case. Does me remember on a topic / discusion wioht Paul Dorfman. The statement: "A tape unit is faster than a hard disk drive". Doe sounds weird and both of us are convinced by experience it is true.  Why? - The condition is a serial approach for both as needs with backups.   - The tape is optimized for that without any locks enques or whatever caching being optimized for that. - The Dasd unit shoudl be able to be multi-user. Many of those coming for possible requests and prioritizing for those. As that is needing the introdcution for enqueing locking etc complexity in routines. Adding a log of cpu memory resources for the same action as tape. It is that overhead thats is the iomportant difference.   Going for the caching with write at (OS) the gain is having the signal writing is finished (just as in old days moving physcial actuator spinnign - ramac). But the real fact isit has to be done yet. Do not unplug your machine in har way it will lost what is already done....   Not a real problem as whn it happens you have to go back in some time and restart. Just make your coding habits to folllow avoidance of these kind of effects. When you don not understand your system your system will outsmart you. Mostly not in a positive result. ... View more