What is your use case?  That matters the most.

On Fri, Jun 23, 2017 at 4:31 PM David Turner <[email protected]> wrote:

> 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 <[email protected]>
> 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 <[email protected]>
>> 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 <
>>> [email protected]> 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
>>> >> [email protected]
>>> >> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
>>> >>
>>> >
>>> >
>>>
>>> _______________________________________________
>>> ceph-users mailing list
>>> [email protected]
>>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
>>>
>>
>>
_______________________________________________
ceph-users mailing list
[email protected]
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com

Reply via email to