How to disable hard disk write cache?

[Xin Li]

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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.

Cheers,
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