Re: [ANNOUNCE] bcachefs!

Killian De Volder
2015-07-22T07:19:31Z

On 21-07-15 20:37, David Mohr wrote:

> one quick question about the roadmap at this point: As far as I understand bcachefs basically integrates bcache features directly in the filesystem.
> So does this deprecate bcache itself in your opinion? Bcache is obviously still useful for other FS, but I just want to know how things will get maintained in the future.

If they remove bcache from the kernel a lot of peaple are going to have serious troubles, as it's not easy to remove.
But to quote the developer:
"no don't worry. it's not going to be deleted from upstream"

> I wanted to suggest / possibly start implementing bcache support for the debian installer - obviously that only makes sense if I can expect it to be in the mainline kernel for the foreseeable future :-).

I can also make a quote on this question:
"the btree code is also hugely improved over what's in mainline, i'd like to get the improvements backported but i think it's just way way too much work"
"bcache will be deprecated when a stable bcachefs is upstream (but it's going to be awhile before the on disk format is stable again)"

More info on what bcachefs actually is:
You initialize some fast storage as a caching-device. These store a btree-journal-change (or whatever is actually used internally) key-value storage system on disk.
Next you can use this btree-caching-device to put a file system on top OR use it to store the cache data for a caching-block-device.
(Not sure if you can combine a caching device and a backing device into the same FS, but you will probably be able to.)

--
Killian De Volder