> So hdparam -W 0 /dev/sdx doesn't work or it makes no difference? 

I wrote "We found the raw throughput in fio benchmarks to be very different for 
write-cache enabled and disabled, exactly as explained in the performance 
article.", so yes, it makes a huge difference.

> Also I am not sure I understand why it should happen before OSD have been 
> started. 
> At least in my experience hdparam does it to hardware regardless.

I'm not sure I understand this question. Ideally it happens at boot time and if 
this doesn't work, at least sometimes before the OSD is started. Why and how 
else would one want this to happen?

Best regards,

Frank Schilder
AIT Risø Campus
Bygning 109, rum S14
ceph-users mailing list

Reply via email to