[mythtv-users] Re: A warning about Samsung HDDs

[Brady]

I am not so sure about modern drives. They changed the way that they
handle spindle connections after I stopped killing drives for a
living. However I can tell you this: it is very common for a drive
that has been spinning for long periods to simply not spin back up.
The motor can continue spinning the drive but doesn't have enough
power to start it spinning again. This is why a reboot of an entire
cluster often means four or five systems keeling over due to bad
fans/hard drives.

Most drives will last a long time if left on. However, this is a bad
things to rely on as the dive may just up and barf one reboot.

Usually I find that spun down drives die far less often when paired
with a cheap power supply. If your power supply isn't top notch then
spin down your drive and reduce the risk of power problems. If you
have top notch drives then keep them spinning so you can reduce the
wear during start/stop. By high quality I am not just talking about
"$100 or more" I am talking about a nice regulated supply that has
tight tolerances.

Mostly I go by a simple rule: A drive should only spin up/down about
once per day.


On 11/1/05, Tony Lill <ajlill at ajlc.waterloo.on.ca> wrote:
> Dewey Smolka <dsmolka at gmail.com> writes:
>
> > As someone who has professionally destroyed hard drives (most of us
> > here are only practiced amateurs), what kind of recommendations/ best
> > practices can you offer to ensure maximum HDD life? What are some
> > warning signs we should look for, other than 'my drive has come to a
> > literal screeching halt'? SMART is nifty, but in my experience has
> > only warned me of problems after I knew there were problems. What can
> > I do to detect a drive failure before it occurs, and to get my data
> > off before the drive becomes unreadable?
>
> First, a question. What's the current philosophy on spinning down
> drives? Is it better or worse for longevity that keeping them spinning
> and idle? I've got my recordings spread across a bunch of drives, 5
> are exclusively used by myth, with a spin-down time of about 20
> minutes. Given the typical myth usage, these can stay spun down for hours.
>
> Now for some answers.
>
> I've had 2 out of 3 Samsung harddrives die on me last year, both
> within about 6 months of being installed. These were slow deaths, and
> I got a lot of read and write errors logged, and so was able to
> recover most of my data before they completely packed it in. This
> permanently put me off using LVM without RAID or mirroring to back it
> up.
>
> First thing is that you should monitor the logs in /var/log. Use
> logcheck or logwatch, which should both be standard packages on most
> recent OS's, and actually READ the mail they send. Any harddrive
> messages like read or write errors, dma errors, ide resets should send
> up a red flag.
>
> If you are smart and not using LVM, then if the filesystem is still
> healthy enough to mount, you can just use tar or cpio or cp -R to get
> your stuff off the drive and on to a replacement.
>
> If not, then dd_rescue is your best friend. It's designed to try and
> extract as much data off of a broken drive as possible, and copy it
> block by block to a new drive. Knoppix has dd_rescue on it, so unless
> you have a spare machine to do the recover on, you'll need a copy of
> that on a CD, just in case. Actually, everyone should have a copy of
> Knoppix, just in case.
>
> You need to get a new drive at least as big as the old one, and
> partition is so each slice you want to recover is at least as big as
> the old slices. Be careful if you buy the "same" size drive from a
> different manufacturer. You can wind up a a few Mb short, in which
> case you're boned if you're using LVM. If you're not getting exactly
> the same replacement drive, go for a bigger one.
>
> Put the broken and replacement drive in the same machine, and use
> dd_rescue to copy the data, and when it's done, fsck the results. If
> you're lucky, you'll have a working filesystem without too many
> missing or corrupt files. If not, well, you've been making regular
> backups of everything important, right?
>
> If your replacement drive is much larger than the original, you can
> make the partitions much larger, and use your filessytem tools to
> extend the filesystems into the new space.
>
> If you are using LVM, your only option is dd_rescue, since what's on
> the disk is just part of the filesystem data, and has no independent
> existence. You need to replace it as exactly as possible.
>
> If you created the PV on the whole disk instead of a partition, I
> don't know if you can add any extra space on the replacement disk to
> the PV, so if you get a larger disk, the extra space may be wasted. If
> you used a partition, you can always add a new partition to your LVM
> after you're done.
>
> Once you finished with using dd_rescue to recover what data you can,
> you need to replace the broken drive with the new drive, bring the
> logical volume up, and then run fsck, and pray.
> --
> Tony Lill,                         Tony.Lill at AJLC.Waterloo.ON.CA
> President, A. J. Lill Consultants        fax/data (519) 650 3571
> 539 Grand Valley Dr., Cambridge, Ont. N3H 2S2     (519) 241 2461
> --------------- http://www.ajlc.waterloo.on.ca/ ----------------
> "Welcome to All Things UNIX, where if it's not UNIX, it's CRAP!"
>
>
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