[kochi_hw_club] hard disk myths part 3
- From: Sameer Thahir <sameerthahir@xxxxxxxxx>
- To: kochi_hw_club@xxxxxxxxxxxxx
- Date: Mon, 12 Jul 2004 11:17:57 -0700 (PDT)
dear hardware club members,
heres the last of the hard disk myth series
sorr piyush for not answering ur query, ill
do it soon
/////////////////////////////////////////////
Myth 11:The head actuators are powered by a motor that
can fail due to excessive use
Truth:Current head actuators are actually not powered
by any motor .
Yes ,in the past head actuators were powered by a
stepper motor.But current head actuators use the
voice coil mechanism which uses electro magnetic
force to move the heads. So if the head actuators are
not powered by any mechanical motor,how can "its
motor" fail?
....................................
Myth 12:Frequent parking of the read/write heads will
make the head actuator's motor fail earlier
Truth:See Myth 11 regarding the actuator's motor.
In addition ,please note that head parking in current
hard disks occurs automatically whenever
power is cut or when the hard disk powers down .It is
not an active process
The head actuators actually have springs to keep them
in place.When there is power ,the actuators are
moved against the spring tension.When power is cut the
actuators automatically retract .Therefore even if
head actuators were powered by a motor,Head parking
will never cause that motor to fail
........................................
Myth 13:The hard disk only spins up when it needs to
read or write data .It spins down when it is idle
Truth:Actually the platters are kept spinning all the
time,unless you have set it to spin down to save power
after some idle time
...............................................
Myth 14:It is better to spin down the hard disk
whenever you can to reduce stress on the spindle motor
Truth:Normally the platters are spun up at start up
and kept spinning after that .The spinning up process
is the most taxing part on the hard disk's spindle
motor .Maintaining the spindle
speed requires a lot less effort
If the platters have spun down and you need to
read/write something on the platters ,you will need to
spin up the platters to full speed before you can read
or write.
Therefore,it is better to keep the hard disk spinning
for better performance and to reduce stress on the
spindle motor
...........................
Myth 15:Sudden power cuts can cause bad sectors!
Truth:Bad sectors are not caused by shutting off your
computer suddenly
It used to be in the case in the old,OLD days when you
had to park the hard disk heads before you turned off
your computer .These days ,the voice coil actuators
will automatically park the read/write heads
whenever power to the hard disk is cut off.
Therefore ,there is no risk of any head crashes that
can create bad sectors.
...............................
Myth 16:Some bad sectors are "virtual" bad sectors
that can be repaired by formatting the hard disk .
Truth:There are also no such things as virtual bad
sectors and physical badsectors
A bad sector is a sector that cannot be written to or
read from properly.It can be due to an eroded media or
direct physical damage to the media. It cannot be
repaired
by any software and formatting will not restore it.
...................................
Myth 17:There is nothing to worry about bad sectors
because you can "erase" them by formatting the hard
disk.
Truth:True,low level formatting can replace bad
sectors with good sectors on the spare tracks that are
part of every hard disk.
However ,performance suffers because the heads have to
seek to the spare tracks.In addition ,there are only a
limited number of spare sectors available on any hard
disk.
Finally bad sectors are a sign that something is wrong
with the hard disk .Even if it was due to a single
head crash ,that traumatic event would have created
debris within the platter compartment and a damaged
head.The debris can gradually cause scratches and
erosions on other parts of the platter while a damaged
head will not be aerodynamically stable and will be
more likely to crash in the future.
In other words ,if you have critical data,it would be
a smart thing to back up your data and replace the
hard disk when you detecting bad sectors.The hard
disk may go on for a long time without more bad
sectors appearing but the risk of it dying is real and
should not be ignored.
.......................................
Myth 18:You must format your hard disk every <insert
duration of choice>to improve performance.
Truth:This is yet another common fallacy.Formatting
your hard disk regularly will NOT improve your hard
disk's performance.
If you notice a significant degradation in your hard
disk's performance after several months ,this is
because the data in the hard disk has become so
fragmented that the read/write heads have to seek all
over the hard disk while reading or writing data .
Try defragmenting your hard disk ,instead of simply
formatting it.
....................
Myth 19:The hard disk can only be installed in the
horizontal position
Truth:Hard disks can be installed in any
position-horizontal,vertical,even upside down!.
..............................
Myth 20:If you want to use a hard disk in the
vertical position ,you must first reformat it in the
vertical position.
Truth:Hard disks will work in any position .You do
NOT need to reformat it before using it in vertical
position or even upside down .
.............................
THE AUTHOR IS 4TH YEAR GRADUATE STUDENT OF COMPUTER
SCIENCE.)
__________________________________
Do you Yahoo!?
New and Improved Yahoo! Mail - Send 10MB messages!
http://promotions.yahoo.com/new_mail
Other related posts:
- » [kochi_hw_club] hard disk myths part 3
