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SubjectRe: [ANNOUNCE] Ramback: faster than a speeding bullet
On Wednesday 12 March 2008 05:01, wrote:
> wrote on 10/03/2008 06:46:16:
> > Every little factor of 25 performance increase really helps.
> >
> > Ramback is a new virtual device with the ability to back a ramdisk
> > by a real disk, obtaining the performance level of a ramdisk but with
> > the data durability of a hard disk. To work this magic, ramback needs
> > a little help from a UPS. In a typical test, ramback reduced a 25
> > second file operation[1] to under one second including sync. Even
> > greater gains are possible for seek-intensive applications.
> What about doing a similar thing as a device mapper target? Have a look a
> dm-cache, I know that development of that has stopped but it doesn't mean
> it couldn't be ressurected. It has an advantage that it is generic (any
> two block devices will do) and you don't need to populate the "cache" on
> start-up - it happens automatically through cache misses.

It is a device mapper target (though there is no real advantage in that
other than having a handy plug-in api). It does handle any two block
devices, and it does populate on cache miss. But also has daemon-driven
population, since it never makes sense to leave the backing disk idle
then have to incur read latency because of that later.



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