This issue has been extensively covered in the press recently and, as
should be blindingly obvious by now, is, by and large, nonsense.

First of all, let me make this absolutely clear - you should pay ZERO
attention to the number reported by smartctl for Load_Cycle_Count. It is
probably not a raw counter showing the number of times your drive heads
have unparked. If you don't believe me, look at this output from my
Thinkpad X40:

193 Load_Cycle_Count        0x0032   070   070   000    Old_age   Always
-       3037783573354

That number is over 3 *trillion*, which, for a 14 month old laptop is
physically impossible, it would have to be unparking the heads 80,000
times *a second*. Again, this is physically impossible.

What you should be paying attention to are the THRESH, VALUE and WORST
columns. This is an Old_age SMART value, so the VALUE starts at 100 and
counts down to 0. When it crosses THRESH it means your drive
manufacturer believes your drive has reached the end of its probable
lifespan.

So, in my above example, the THRESH, VALUE and WORST columns are 70, 70
and 0 respectively. In this case VALUE and WORST will always be the same
because it's simply counting down over time and in this case, I have
used about 30% of the expected lifespan of my drive, which, at 14 months
and it being a rubbishy 1.8" laptop drive, seems entirely reasonable.

My value will be lower than a stock install would because I've had
laptop_mode enabled for at least a year, so the heads are unparking
quite aggressively.

So, to be absolutely, entirely clear about this, Ubuntu is not killing
my hard disk, no matter what Slashdot and misinformed blog posts claim.

To everyone who has commented on this bug with wild claims about how
much their Load_Cycle_Count value is increasing, go back to smartctl's
output and check the VALUE and THRESH columns and I am entirely
confident you will find that your drive is well within expected
lifespan.

The reason is because the RAW_VALUE column is entirely manufacturer
specific. A few drives will actually report a counter of the number of
times they've unparked the heads, but many/most report something that we
have no idea about the meaning of. It's not a meaningful number. SMART
is not designed to report meaningful numbers like that, it is designed
to provide an indication of health that is interpreted by the firmware
on the drive itself, this is what the VALUE, THRESH and WORST columns
are for. Use them.

-- 
High frequency of load/unload cycles on some hard disks may shorten lifetime
https://bugs.launchpad.net/bugs/59695
You received this bug notification because you are a member of Ubuntu
Bugs, which is the bug contact for Ubuntu.

-- 
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to