FreeBSD on SSD

[Wojciech Puchar]

> The read-cache idea is very sound, mainly because by using it this way Seagate would not have to create a special set of
> instructions for installing and using the HDD.

I don't think that this drive cache is smart enough to really cache needed 
things and not flush that cache with useless data too often.

i personally would prefer that drive to show up as 8GB disk and 750 GB 
disk.

It would be easy to fit most of /usr in 8GB with even large set of 
software installed.

when out of space then use softlinks and move not very used things (eg. 
documentation, non-yours locales, examples, some linarly accessed big 
files etc.) to disk.

> My final question would be :
> 
> Seeing as the HDD only has a SATA connector, this would mean that the SSD part already has a memory control device that regulates
> access to that sector, whether it is a plain read-cache or not. This would imply that FreeBSD could communicate with the HDD
> normally, through the SATA connector, just like any regular HDD.

indeed.

Such a drive is a good idea, but complete lack of documentation (how it 
operate) is not.

You have to guess how this SSD-cache works because it is not documented.

the other thing is erasing data. You want to sell that drive and clear 
your data by

dd if=/dev/zero of=/dev/disk bs=1m

but does it clear SSD cache? i don't think so. Someone sophisticated 
enough would perform raw read of cache chips and get cached data, which 
can actually be the most important part (things you work on often).