Tim, Great stuff. I'm going to respond in smaller chunks, to keep subtopics in their own subthreads.
Tim Foster wrote:
You might be interested in reading Eric's post at: http://blogs.sun.com/erickustarz/entry/zfs_on_a_laptop It has more things we might want to keep in mind: * set "copies" > 1 for the root filesystem (and anything the user cares about on a single-disk installation, obviously decided automatically as a function of total available disk-space, user-override allowed of course) * set compression = on
Nice! Given the size of today's laptop disks, I don't think it's at all unreasonable for copies to be (at least) 2 for all blocks, particularly with compression enabled by default too (though as you mention, it should be easy to turn it off if desired (and should be automatically turned off if free space is below a certain threshold). How does the system respond if it finds a bad block? Ideally, it puts a copy somewhere else and keeps going, though if it runs into this enough times, the user should be warned (since it probably indicates impending catastrophic failure). Anywhere I can find numbers for 1. typical space savings; and 2. typical performance degradation when compression is on, so I have a better idea of the tradeoff?
A commenter to Eric's post asks about potential impacts to battery-life these may have - I've absolutely no idea, but if someone wants to send me a new laptop and a stopwatch, I'll check it out.
I would think the battery impact of reading the block from the disk would far outweigh the battery impact of decompressing its contents, but that's just a guess. -ian -- Ian Murdock 650-331-9324 http://ianmurdock.com/ "Don't look back--something might be gaining on you." --Satchel Paige _______________________________________________ indiana-discuss mailing list [email protected] http://opensolaris.org/mailman/listinfo/indiana-discuss
