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How does flashcache compare to dm-cache / bcache, integrated into linux kernels 3.9 and 3.10? The text mentions that it works as a device mapper module, so doe
by McGlockenshire 13y ago
How does flashcache compare to dm-cache / bcache, integrated into linux kernels 3.9 and 3.10?
The text mentions that it works as a device mapper module, so does it actually work with dm-cache?
The readme on github suggests that it targets older kernel versions, most of which look like versions that ship in RHEL & Ubuntu LTS.
- viraptor 13y agoThe best thing is that you don't have to prepare the original partitions in any specific way, like with bcache. You just add new partion and say - this is a cache for volume /dev/.... and it works. I don't know about performance differences - haven't used bcache that much. The versions in readme are slightly out of date. Maybe that's what facebook uses internally, but the driver seems to work perfectly with higher versions. I submitted some patches to update function signatures in 3.9, but that was only to get rid of compilation warnings - everything else still works.
- nwmcsween 13y agobcache should be faster, it's at a lower level, That said there are differences mainly the block size and distribution algorithm but could be easily 'fixed' given patches and benchmarks.