Re: Slow disks.

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From: Greg Freemyer
Date: Sunday, December 26, 2010 - 4:17 pm

On Sun, Dec 26, 2010 at 4:40 PM, Rogier Wolff <R.E.Wolff@bitwizard.nl> wrote:

It sounds like you have 3 or 4 separate issues that are each costing
you a factor of 3 or so of pain.

3 * 3 * 3 *3 = 81  ( I don't recall how bad your overall problem was).

I can remember:

Raid 5 - poor choice for 4KB random writes - a factor of 2-4
Misaligned 4KB physical sectors - a factor of 2+
Excessive Head Parking  (You show 100K plus head parks in your smart
data) - (who knows.  It takes a while to un-park the heads and your
heads are parking way too often.)

I think you said it was a 8TB, I know its a pain, but I'd rebuild.  I
don't know how reliable various large drives are currently.  in
2008/2009 they seemed to be horrible and the advice was to use drives
from different vendors, etc so you would be less likely to have a
batch of drives go bad all at once.

Good Luck
Greg
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Messages in current thread:
Slow disks. , Rogier Wolff, (Mon Dec 20, 7:15 am)
Re: Slow disks., Bruno Prémont, (Mon Dec 20, 11:06 am)
Re: Slow disks., Greg Freemyer, (Mon Dec 20, 11:32 am)
Re: Slow disks., Jeff Moyer, (Mon Dec 20, 12:09 pm)
Re: Slow disks., Rogier Wolff, (Wed Dec 22, 3:43 am)
Re: Slow disks., Greg Freemyer, (Wed Dec 22, 8:59 am)
Re: Slow disks., Jeff Moyer, (Wed Dec 22, 9:27 am)
Re: Slow disks., David Rees, (Wed Dec 22, 1:52 pm)
Re: Slow disks., Rogier Wolff, (Wed Dec 22, 3:44 pm)
Re: Slow disks., Rogier Wolff, (Wed Dec 22, 3:46 pm)
Re: Slow disks., David Rees, (Wed Dec 22, 4:13 pm)
Re: Slow disks., Jeff Moyer, (Thu Dec 23, 7:40 am)
Re: Slow disks., Rogier Wolff, (Thu Dec 23, 10:01 am)
Re: Slow disks., Jaap Crezee, (Thu Dec 23, 10:05 am)
Re: Slow disks., Jeff Moyer, (Thu Dec 23, 10:47 am)
Re: Slow disks., Greg Freemyer, (Thu Dec 23, 11:51 am)
Re: Slow disks., Jaap Crezee, (Thu Dec 23, 12:10 pm)
Re: Slow disks., Greg Freemyer, (Thu Dec 23, 3:09 pm)
Re: Slow disks., Rogier Wolff, (Fri Dec 24, 3:45 am)
Re: Slow disks., Rogier Wolff, (Fri Dec 24, 4:40 am)
Re: Slow disks., Krzysztof Halasa, (Fri Dec 24, 6:01 am)
Re: Slow disks., Michael Tokarev, (Fri Dec 24, 8:24 am)
Re: Slow disks., Krzysztof Halasa, (Fri Dec 24, 1:58 pm)
Re: Slow disks., Rogier Wolff, (Sat Dec 25, 5:14 am)
Re: Slow disks., Mikael Abrahamsson, (Sat Dec 25, 5:19 am)
Re: Slow disks., Jaap Crezee, (Sat Dec 25, 11:12 am)
Re: Slow disks., Michael Tokarev, (Sat Dec 25, 2:28 pm)
Re: Slow disks., Rogier Wolff, (Sun Dec 26, 2:40 pm)
Re: Slow disks., Niels, (Sun Dec 26, 3:07 pm)
Re: Slow disks., Greg Freemyer, (Sun Dec 26, 4:05 pm)
Re: Slow disks., Greg Freemyer, (Sun Dec 26, 4:17 pm)
Re: Slow disks., Mark Knecht, (Sun Dec 26, 4:38 pm)
Re: Slow disks., Rogier Wolff, (Sun Dec 26, 4:49 pm)
Re: Slow disks., Rogier Wolff, (Sun Dec 26, 5:27 pm)
Re: Slow disks., Rogier Wolff, (Sun Dec 26, 5:34 pm)
Re: Slow disks., Mark Knecht, (Sun Dec 26, 8:12 pm)
Re: Slow disks., Tejun Heo, (Mon Dec 27, 3:56 am)
Re: Slow disks., Krzysztof Halasa, (Mon Dec 27, 11:20 am)