hdparm error: Was Re: [Beowulf] Help for terrible NFS write performance

[Gus Correa]

Prentice Bisbal wrote:
> Joe Landman wrote:
>> So do most people.  If your node crashes, do you get data loss?  If your
>> server crashes, will you get data loss?  I am guessing that if you do an
>>
>>     hdparm -W /dev/sd*
> 
> Just following this thread. When I try that command, I get an error:
> 
>  hdparm -W /dev/sd*
> -W: missing value (0/1)
> 
> /dev/sda:
> 
> 
> /dev/sdg:
> 
> --
> Prentice
> 

Somehow it works on Fedora 10, but not on CentOS 4 and 5.

# uname -r
2.6.27.25-170.2.72.fc10.i686
# hdparm -W /dev/sda

/dev/sda:
  write-caching =  1 (on)

**

# uname -r
2.6.18-92.1.22.el5
# hdparm -W /dev/sda
-W: missing value (0/1)

/dev/sda:

**

The hdparm man page says:

"Some options may work correctly only with the latest kernels."

Gus Correa