From: Nifty Fedora Mitch <niftyfedora@niftyegg.com>
To: Goswin von Brederlow <goswin-v-b@web.de>
Cc: John Robinson <john.robinson@anonymous.org.uk>,
Linux RAID <linux-raid@vger.kernel.org>
Subject: Re: Awful RAID5 random read performance
Date: Thu, 4 Jun 2009 15:40:54 -0700 [thread overview]
Message-ID: <20090604224054.GA17121@compegg.wr.niftyegg.com> (raw)
In-Reply-To: <878wk9q7qp.fsf@frosties.localdomain>
On Thu, Jun 04, 2009 at 12:21:02AM +0200, Goswin von Brederlow wrote:
.....mi
>
> Anyone know what the size of a track is on modern disks? How many
> sectors/track do they have?
The number will differ from the inside to the outside of the
disk. The number of zones will differ from drive to drive too....
Some diagnostic software will either know this or
have vendor specific ways to get it live from the disk.
Data sheets now report average... At one time vendors
made a big deal on this...
http://www.impediment.com/seagate/s2000/spec_318436lcv.shtml
Sectors/Track (avg) 426
Bytes/Track (avg) 218,112
If you take numbers like:
Track Density (TPI) 18,145 tracks/inch
Recording Density (BPI, max) 328,272 bits/inch
and dust off some geometry you might discover
how many more bits are possible on the outside
tracks vs the inside tracks and then take those
bits and estimate the number of additional blocks.
An estimate may all you get because spares and
other uses for bits will be hidden.
--
T o m M i t c h e l l
Found me a new hat, now what?
next prev parent reply other threads:[~2009-06-04 22:40 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-30 21:46 Awful RAID5 random read performance Maurice Hilarius
2009-05-31 6:25 ` Michael Tokarev
2009-05-31 7:47 ` Thomas Fjellstrom
2009-05-31 12:29 ` John Robinson
2009-05-31 15:41 ` Leslie Rhorer
2009-05-31 16:56 ` Thomas Fjellstrom
2009-05-31 18:26 ` Keld Jørn Simonsen
2009-06-02 18:54 ` Bill Davidsen
2009-06-02 19:47 ` Keld Jørn Simonsen
2009-06-02 23:13 ` John Robinson
2009-06-03 18:38 ` Bill Davidsen
2009-06-03 19:57 ` John Robinson
2009-06-03 22:21 ` Goswin von Brederlow
2009-06-04 11:23 ` Keld Jørn Simonsen
2009-06-04 22:40 ` Nifty Fedora Mitch [this message]
2009-06-06 23:06 ` Bill Davidsen
2009-06-01 1:19 ` Carlos Carvalho
2009-06-01 4:57 ` Leslie Rhorer
2009-06-01 5:39 ` Thomas Fjellstrom
2009-06-01 12:43 ` Maurice Hilarius
2009-06-02 14:57 ` Wil Reichert
2009-06-02 15:14 ` Maurice Hilarius
2009-06-02 19:47 ` Bill Davidsen
2009-06-01 11:41 ` Goswin von Brederlow
2009-06-03 1:57 ` Leslie Rhorer
2009-05-31 17:19 ` Goswin von Brederlow
2009-06-01 12:01 ` John Robinson
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