External journal on flash drive

[Mika Liljeberg]

Hi,

I'd like to use a flash drive as a journal device, with the purpose of
keeping the main disk drive spun down as long as possible. I have a
couple of questions:

1) Does the journaling code spread write accesses to the journal device
evenly, as I hope, or are there blocks that are particularly "hot"?
I.e., do I have to worry about the flash device dying quickly because of
frequent erase/rewrite cycles to a small number of blocks?

2) Currently, the main drive seems to spin up within 60 seconds after a
write access. I would like the checkpointing to occur only when the
journal device is getting full. How can I tune this?

Thanks,

	MikaL