How to disable hard disk write cache?

[Matthias Andree]

Am 21.09.2014 um 10:42 schrieb Xin Li:
> On 9/21/14 4:34 PM, Matthias Andree wrote:
>> Am 16.09.2014 um 16:09 schrieb Xin Li:
> 
>>> Modern SATA/SAS/SCSI devices usually comes with the capability
>>> of tagged commands, allowing the OS to know when a write buffer
>>> is on stable storage.  With this, file systems can easily
>>> implement the right semantics and recover from e.g. a power
>>> outage, etc.
> 
>> Yes, they *can easily implement* that, but which file systems in
>> FreeBSD *actually do* that?
> 
> Both UFS (with Soft Updates, which is what it's all about; I haven't
> checked the Journalled Soft Updates case) and ZFS do that for ages.

Thank you.  Is this in any of the 9.3 manpages so I could look that up
rather than ask questions on the lists? :-)