Matt Thomas matt@3am-software.com

> Also, when initializing the buffer cache (actually, when opening a disk 
> partition any pending write in the NVRAM are written to the disk before 
> allowing the open to finish.  This is needed so that fsck (since it bypasses the buffer 
> cache) will always get a true image of the filesystem.
>
> The above techniques still have merit even today.  I've been talking to a 
> friend which does hardware design about designing a PCI board that could have 
> 1-2GB of NVRAM (which you can DMA to/from system memory to the
> NVRAM).  Imagine a board that could "act" as your disk with full PCI 
> bandwidth I/O rates. :)

Prestoserve was VME add-on board for Sun3s.  Remember at that time CPU
ran quite slowly, disk capacity and its speed were joke, and 10Mbps yellow cable
was a messy unreliable _shared_ (single carrier signal) media.   Adding
Prestoserve VME card to Sun3 desk side cage brought instant and striking
pleasure for NFS client users.  Prestoserve also made possible no data lossage
upon system crash which was not uncommon in field.

Year 2003 expects 200GB ~ 300GB disk drives on sale.  They will have
20MB ~30MB disk cache inside drivers.   I'm uncertain Prestoserve-like
device can make sense although some sort of "semiconductor-assist" for
block I/O of operating systems might worth of research.

Toru Nishimura/ALKYL Technology