use bcache with /dev/zram as caching device

use bcache with /dev/zram as caching device

[Ansgar Jazdzewski]

hi,

we like to use bcache with a ramdrive as cache but during the
configuration i received some errors possibly be timing related.

some one of you tryed to have a ram device as chache? before you ask:
we like to try to speed up a elasticsearch cluster so a server fail is
not an issue.

Best,
Ansgar

Re: use bcache with /dev/zram as caching device

[Denis Bychkov]

Do you mean you don't care about the state of the file system after a
reboot? Do you rebuild it from scratch each time on restart? Even so,
bcache was designed around SSD media behavior, there are some notions
non-applicable to zram drives, like buckets. They might introduce some
inefficiencies, but should not affect the semantics. Could show the
errors you receive.
Also, could it be zram-related? Did you try RAM block devices instead?
What IO scheduler do you use on zram? Could you try noop and see what
happens?

On Fri, Aug 28, 2015 at 1:47 AM, Ansgar Jazdzewski
<a.jazdzewski@googlemail.com> wrote:
> hi,
>
> we like to use bcache with a ramdrive as cache but during the
> configuration i received some errors possibly be timing related.
>
> some one of you tryed to have a ram device as chache? before you ask:
> we like to try to speed up a elasticsearch cluster so a server fail is
> not an issue.
>
> Best,
> Ansgar
> --
> To unsubscribe from this list: send the line "unsubscribe linux-bcache" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html



-- 

Denis