* difference between qemu cache settings and ceph.conf rbd cache settings?
@ 2012-06-19 6:37 Stefan Priebe - Profihost AG
2012-06-19 6:42 ` Josh Durgin
0 siblings, 1 reply; 3+ messages in thread
From: Stefan Priebe - Profihost AG @ 2012-06-19 6:37 UTC (permalink / raw)
To: ceph-devel
Hello list,
i've now patched my qemu to include the qemu cache settings for rbd.
Now i can change my drive caching mode. But there are also these
settings for global section in ceph.conf.
rbd_cache = true
rbd_cache_size = 33554432
rbd_cache_max_age = 2.0
How do they influence or replace each other?
thanks
Stefan
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: difference between qemu cache settings and ceph.conf rbd cache settings?
2012-06-19 6:37 difference between qemu cache settings and ceph.conf rbd cache settings? Stefan Priebe - Profihost AG
@ 2012-06-19 6:42 ` Josh Durgin
2012-06-19 6:44 ` Stefan Priebe - Profihost AG
0 siblings, 1 reply; 3+ messages in thread
From: Josh Durgin @ 2012-06-19 6:42 UTC (permalink / raw)
To: Stefan Priebe - Profihost AG; +Cc: ceph-devel
On 06/18/2012 11:37 PM, Stefan Priebe - Profihost AG wrote:
> Hello list,
>
> i've now patched my qemu to include the qemu cache settings for rbd.
>
> Now i can change my drive caching mode. But there are also these
> settings for global section in ceph.conf.
>
> rbd_cache = true
> rbd_cache_size = 33554432
> rbd_cache_max_age = 2.0
>
> How do they influence or replace each other?
>
> thanks
> Stefan
In qemu, the cache settings map to:
writeback:
rbd_cache = true
writethrough:
rbd_cache = true
rbd_cache_max_dirty = 0
none:
rbd_cache = false
qemu's settings are overridden by any custom settings you have in a
config file or on the qemu command line.
Josh
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: difference between qemu cache settings and ceph.conf rbd cache settings?
2012-06-19 6:42 ` Josh Durgin
@ 2012-06-19 6:44 ` Stefan Priebe - Profihost AG
0 siblings, 0 replies; 3+ messages in thread
From: Stefan Priebe - Profihost AG @ 2012-06-19 6:44 UTC (permalink / raw)
To: Josh Durgin; +Cc: ceph-devel
Am 19.06.2012 08:42, schrieb Josh Durgin:
> In qemu, the cache settings map to:
>
> writeback:
> rbd_cache = true
>
> writethrough:
> rbd_cache = true
> rbd_cache_max_dirty = 0
>
> none:
> rbd_cache = false
>
> qemu's settings are overridden by any custom settings you have in a
> config file or on the qemu command line.
Thanks!
Stefan
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2012-06-19 6:44 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2012-06-19 6:37 difference between qemu cache settings and ceph.conf rbd cache settings? Stefan Priebe - Profihost AG
2012-06-19 6:42 ` Josh Durgin
2012-06-19 6:44 ` Stefan Priebe - Profihost AG
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