hdparm problem

[jd1008]

On 03/20/2015 01:36 PM, Joe Zeff wrote:
> On 03/20/2015 12:25 PM, jd1008 wrote:
>> Man page says only choices are
>>    u
>> and
>>   m
>>
>> Does not mention a - preceding either one.
>
> Look at the usage you quoted, and I snipped.  It lists -m, but not 
> simply m.  In fact, I don't know off-hand of a command that allows you 
> to specify an option without either a single or double dash in front 
> of it.
What you say is weird!!

Here is that segment of the man page:

        --user-master USER
               Specifies  which password (user/master) to select.  
Defaults to user password.  Only useful in combina‐
               tion with --security-unlock, --security-set-pass, 
--security-disable, --security-erase  or --security-
               erase-enhanced.
                       u       user password
                       m       master password


I do not see any hyphens preceding m or u

Also -m has a totally different usage effect:

        -m     Get/set sector count for multiple sector I/O on the 
drive.  A setting of 0 disables this feature.  Mul‐
               tiple sector mode (aka IDE Block Mode), is a feature of 
most modern IDE  hard  drives,  permitting  the
               transfer  of  multiple sectors per I/O interrupt, rather 
than the usual one sector per interrupt.  When
               this feature is enabled, it typically reduces operating 
system overhead for disk  I/O  by  30-50%.   On
               many systems, it also provides increased data throughput 
of anywhere from 5% to 50%.  Some drives, how‐
               ever (most notably the WD Caviar series), seem to run 
slower with multiple mode enabled.  Your  mileage
               may  vary.   Most drives support the minimum settings of 
2, 4, 8, or 16 (sectors).  Larger settings may
               also be possible, depending on the drive.  A setting of 
16 or 32 seems optimal on many systems.   West‐
               ern  Digital recommends lower settings of 4 to 8 on many 
of their drives, due tiny (32kB) drive buffers
               and non-optimized buffering algorithms.  The -i option 
can be used to find  the  maximum  setting  sup‐
               ported by an installed drive (look for MaxMultSect in the 
output).  Some drives claim to support multi‐
               ple mode, but lose data at some settings. Under rare 
circumstances, such failures can result  in  mas‐
               sive filesystem corruption.

Maybe you are using some other version???
My hdparm is
# rpm -q hdparm
hdparm-9.45-1.fc21.x86_64