I've never used nbd-rbd, I would use rbd-fuse. It's version should match your cluster's running version as it's a package compiled with each ceph release.
On Fri, Jun 23, 2017 at 3:58 PM Massimiliano Cuttini <max@xxxxxxxxxxxxx> wrote:
Ok,
so if I understand correctly your opinion: if you cannot choiche the kernel then you'll sacrifice immediatly the kernel-rbd.
I was at the same opinion but i'm still harvesting opinion.
Can you tell me if by using nbd-rbd I'm not losing any features?
I just cannot understand if nbd is a sort of "virtualized driver" that use ceph under a less-featured-standardized driver or if kernel and nbd differ only (assuming it's compared with last kernel) just for speed reason.
Thanks Turner for any further info!
Max
Il 23/06/2017 18:21, David Turner ha scritto:
If you have no control over what kernel the clients are going to use, then I wouldn't even consider using the kernel driver for the clients. For me, I would do anything to maintain the ability to use the object map which would require the 4.9 kernel to use with the kernel driver. Because of this and similar improvements to ceph that the kernel is requiring newer and newer versions to utilize, I've become a strong proponent of utilizing the fuse, rgw, and librados/librbd client options to keep my clients in feature parity with my cluster's ceph version.
On Fri, Jun 23, 2017 at 11:50 AM Massimiliano Cuttini <max@xxxxxxxxxxxxx> wrote:
Not all server are real centOS servers.
Some of them are dedicated distribution locked at 7.2 with locked kernel
fixed at 3.10.
Which as far as I can understand need CRUSH_TUNABLES2 and not even 3!
http://cephnotes.ksperis.com/blog/2014/01/21/feature-set-mismatch-error-on-ceph-kernel-client
So what are you suggest to sacrifice?
Kernel-RBD or CRUSH_TUNABLE > 2?
Il 23/06/2017 14:51, Jason Dillaman ha scritto:
> CentOS 7.3's krbd supports Jewel tunables (CRUSH_TUNABLES5) and does
> not support NBD since that driver is disabled out-of-the-box. As an
> alternative for NBD, the goal is to also offer LIO/TCMU starting with
> Luminous and the next point release of CentOS (or a vanilla >=4.12-ish
> kernel).
>
> On Fri, Jun 23, 2017 at 5:31 AM, Massimiliano Cuttini <max@xxxxxxxxxxxxx> wrote:
>> Dear all,
>>
>> running all server and clients a centOS release with a kernel 3.10.* I'm
>> facing this choiche:
>>
>> sacrifice TUNABLES and downgrade all the cluster to
>> CEPH_FEATURE_CRUSH_TUNABLES3 (which should be the right profile for jewel on
>> old kernel 3.10)
>> sacrifice KERNEL RBD and map Ceph by NBD
>>
>> Which one should I sacrifice? And why?
>> Let me know your througth, pro & cons.
>>
>>
>> Thanks,
>> Max
>>
>>
>>
>> _______________________________________________
>> ceph-users mailing list
>> ceph-users@xxxxxxxxxxxxxx
>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
>>
>
>
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