On Sat, Sep 26, 2015 at 10:08 AM, James <[email protected]> wrote: > Florian Gamböck <ml <at> floga.de> writes: >> Now, before I try some crazy stunts like bind-mounting $D and $ED on >> "preinst" >> and cleaning up in "postinst", I wanted to know if some of you guys did >> similar experiments and/or have some advice that you could share with me. > > I have been following 'bcache' as an interesting addition to complex > compiling scenarios. I'm not certain how it will help your 'wild ideas', > but it is worth a look, imho [1]
Honestly, I'm hard-pressed to think of situations where you're better off with anything other than either tmpfs or whatever filesystem your /usr happens to be on. However, if you do want to build on something like bcachefs and you're using an ssd you might just want to use a pure log-based filesystem like f2fs. You can afford to go far more experimental for temp space. I haven't studied the design of bcachefs closely, so I'm not sure how it would compare for this use. I know it has made a bunch of noise lately, though honestly I'm not impressed with some of the hype (not something I blame the authors for - more the groupies). One thing that both zfs and bcachefs seem to be doing (not that I'm in an expert in either) is taking a multi-tiered approach to storage. That is, writes can go into a durable log on a separate device and then be consolidated onto more long-term storage. I suspect that this might help with some of the fragmentation issues that you run into with COW. Then again, I don't know how its performance would compare to just dumping everything right to a single tier like btrfs and then just periodically having some kind of smart defragmenter that just cleans up the stuff that really needs it. -- Rich
