[Discuss] lvm snapshot cloning

[dsr at tao.merseine.nu (Dan Ritter)]

On Wed, Oct 26, 2011 at 03:18:06PM -0400, Edward Ned Harvey wrote:
> > From: markw at mohawksoft.com [mailto:markw at mohawksoft.com]
> >
> > If you can get more than 160MB/s (sustained) on anything other than exotic
> > hardware, I'd be surprised. 1Gbit/sec per disk sustained is currently not
> > possible with COTS hardware that is available.
> > 
> > Transfer rate is not "sustained," and "peak" is not "sustained." Yes, if
> > can can manage to read/write to disk cache, you can get cool performance,
> > but if you are doing backups, you will blow out cache quite quickly.
> 
> Go measure it before you say anymore.  Because I've spent a lot of time in
> the last 4 years benchmarking disks.  I can say the typical sequential
> throughput, read or write, for nearly all disks (7.2krpm sata up to 15krpm
> sas) is 1.0 Gbit/sec.  Sustained sequential read/write.  For let's say, the
> entire disk.  Or at least tens of GB.
> 
> Even laptops (7.2krpm sata dell) are able to sustain this speed.

Erm. 

1 Gb/s * 1024 M/G * 1B/8b = 128MB/s

Anything which can do
160 is clearly capable of doing 128.

You two are arguing in different directions.

-dsr-