Re: Solaris ZFS on Linux

From: Wil Reichert
Date: Wed Aug 02 2006 - 22:19:38 EST


On 8/2/06, Krzysztof Halasa <khc@xxxxxxxxx> wrote:
Kyle Moffett <mrmacman_g4@xxxxxxx> writes:

> IMHO the best alternative for a situation like that is a storage
> controller with a battery-backed cache and a hunk of flash NVRAM for
> when the power shuts off (just in case you run out of battery), as
> well as a separate 1GB battery-backed PCI ramdisk for an external
> journal device (likewise equipped with flash NVRAM). It doesn't take
> much power at all to write a gig of stuff to a small flash chip
> (Think about your digital camera which runs off a couple AA's), so
> with a fair-sized on-board battery pack you could easily transfer its
> data to NVRAM and still have power left to back up data in RAM for 12
> hours or so. That way bootup is fast (no reading 1GB of data from
> NVRAM) but there's no risk of data loss.

Not sure - reading flash is fast, but writing is quite slow.
A digital camera can consume a set of 2 or 4 2500 mAh AA cells
for a fraction of 1 GB (of course, only a part of power goes
to flash).

Seeks are fast, throughput is terrible, power is minimal:

http://techreport.com/reviews/2006q3/supertalent-flashide/index.x?pg=1

Wil
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