Re: disk write barriers

2005-07-07 Thread Matthias Buelow
rom what I understand from some googling, disk write barriers are specially crafted i/o requests (within the vfs/driver infrastructure) that are acted on by block drivers as following: all requests before a barrier request will be completed before any request that follows the barrier is executed. Th

Re: disk write barriers

2005-07-07 Thread Lowell Gilbert
Matthias Buelow <[EMAIL PROTECTED]> writes: > Now my question is: Does FreeBSD also implements these barriers, or an > equivalent mechanism, as claimed on the above URL? Do you have a background in OS design? It affects the answer, because you seem to be referring to access barriers and disk cac

disk write barriers

2005-07-06 Thread Matthias Buelow
Hi folks, I'd like to know something about the (possible) existence of disk write-barriers in FreeBSD. I often read the advice that one should disable write-back caching on modern disks in order to make softupdates actually work. Unfortunately, disabling the write-back cache on typical ATA