On Monday 20 December 2004 17:32, Spam wrote: > What happen with the performance when these barriers are active? It's faster than with disk writecache off. I didn't benchmark barriers=flush and writecache on.
> > Is it only during power failure the data in the write cache is lost? No. See http://support.microsoft.com/kb/153296/EN-US/ > > Also, does anyone know if the data in the disk write cache is > written out if the system crashes/freezes. Power failure is not a > very common occurrence, but crashes are much more so. The cache should stay intact as long the harddisk is supplied with power. > > Is it possible to detect if filesystem was unmounted due to power > failure or due to a kernel crash? Kernel panics don't tend to reset the machine but output a dump to the console /syslog via network and halt the machine. If you have a UPS supplier supporting linux you will receive a power failure notification event to take proper action. For example: http://www2.apcupsd.com/ -- lg, Chris
