[CentOS-docs] Possible typo in "HowTos/Disk_Optimization"

Fri May 29 16:25:57 UTC 2009
S.Tindall <tindall.satwth at brandxmail.com>

On Fri, 2009-05-29 at 10:09 -0400, Phil Schaffner wrote:
> Alan Bartlett wrote:
> ...
> > Pedantically and ignoring the RAID aspect, just looking at the
> > equations scientifically, I would say that only the first one is wrong
> > as (64K / 4K) = 16, not 16K. It should be expressed as (64 / 4)K =
> > 16K.
> > 
> > The other two lines do read correctly but, in the spirit of
> > conformity, I would suggest (3 * 16)K = 48K and (16 + 16)K = 32K,
> > respectively.
> > 
> > Perhaps the original author would care to comment and adjust where necessary?
> > 
> > Alan.
> 
> Direct link is http://wiki.centos.org/HowTos/Disk_Optimization to save 
> others from hunting through the top HowTos page.
> 
> My pedantic sensibilities would render the equations as:
> 
> (64K / 4K) = 16
> (3 * 16) = 48
> 
> The first would be consistent with the usage in item 9 in
> 
> http://tldp.org/HOWTO/Software-RAID-0.4x-HOWTO-8.html
> 
> and "man mke2fs":
> 
>      stride=stripe-size
>        Configure the filesystem for a RAID array with stripe-size
>        filesystem blocks per stripe.
> 
> but the above points up another error on the Wiki page.  There is no "-E 
> stripe-width" parameter to mkfs.ext3/mke2fs.  I'd naively think it 
> should be "-E stride=48", but the conclusion is still that the original 
> author needs to respond, or failing that somebody else needs to fix the 
> errors.
> 
> Phil

Yes, that is a correct construct.

It should look like:

# mkfs.ext3 -E stride=8 /dev/...

...where stride = stripe/4K = 32K/4K = 8 in this raid10 example.


Steve