On Oct 14, 2013, at 2:08 AM, Florian Weimer <fweimer@xxxxxxxxxx> wrote: > On 10/10/2013 12:02 AM, Rolf Fokkens wrote: > >> The Fedora SSD Cache is this sunday October 13th 2013. This Fedora Test >> Day will focus on bcache based SSD Caching in Fedora 20. >> >> https://fedoraproject.org/wiki/Test_Day:2013-10-13_SSD_Cache >> >> If you're interested in trying out the new bcache SSD caching >> functionality step by step instructions are available for: > > Is there a write-up somewhere documenting what strategies are implemented by bcache to keep the SSD and the hard disk contents in sync even in the event of a sudden power loss? I'd check lkml. The conversations go back a few years. But I think it's good to know that getting your data to stable storage means getting it to either the SSD (cache) or HDD (backing device). The migration from cache to backing is COW, so even if that were interrupted it doesn't obliterate the file system. Even for clean shutdowns the cache is dirty, and bcache therefore doesn't really distinguish between clean and unclean shutdowns - so the recovery code is always being exercised. Because of COW and how much faster SSD's commit, overall I'd expect less potential for fs corruption in the face of unclean shutdowns, compared to a non-cached hard drive… assuming there are no bugs that make this supposition wrong. Chris Murphy -- devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
