Sorry, it seemed that I missed this. You can test it via ./ceph_test_librbd_fsx and running "fsxtest" in vm with librbd backend On Fri, Sep 26, 2014 at 4:07 PM, Stefan Priebe - Profihost AG <s.priebe at profihost.ag> wrote: > Hi, > Am 26.09.2014 um 10:02 schrieb Haomai Wang: >> If user enable fiemap feature in osd side, there exists three ways to make >> read/write sprase: >> >> 1. normal sparse read/write op >> 2. clone op >> 3. recover op >> >> If any op doesn't support sparse way, it will destroy the advantage of this >> way and write zero hole to sparse file. Now clone op can support sparse write, >> this commit(https://github.com/ceph/ceph/pull/2137) implement sparse >> read/write for recover op. >> >> The main advantage is if rbd usage, it will hugely reduce the actual >> capacity usage and will make clone/recovery faster! > > OK thanks - but how can i check whether fiemap works on 3.10.55? > > Greets, > Stefan > > >> On Fri, Sep 26, 2014 at 3:53 PM, Stefan Priebe - Profihost AG >> <s.priebe at profihost.ag> wrote: >>> Am 26.09.2014 um 09:36 schrieb Haomai Wang: >>>> Sorry, the bug last mail reported exists in centos 6.5. >>>> >>>> I'm not sure which kernel version solve this bug and 3.12 kernel is >>>> safe with fiemap on XFS >>> >>> What's the advantage of fiemap? I've a vanilla 3.10.55 kernel. >>> >>> Stefan >>> >>>> On Fri, Sep 26, 2014 at 3:33 PM, Haomai Wang <haomaiwang at gmail.com> wrote: >>>>> On Fri, Sep 26, 2014 at 3:04 PM, Stefan Priebe - Profihost AG >>>>> <s.priebe at profihost.ag> wrote: >>>>>> Hi, >>>>>> >>>>>> as the documentation is very unspecific on this option i'm not sure >>>>>> whether we should enable or disable this one on dumpling. >>>>> >>>>> It all depends on your kernel version. For example, as I remember >>>>> there exists known XFS fiemap bug which will return false extent map. >>>>> >>>>> So you must ensure your kernel version with your local filesystem has >>>>> the right fiemap impl. >>>>> >>>>>> >>>>>> Greets, >>>>>> Stefan >>>>>> _______________________________________________ >>>>>> ceph-users mailing list >>>>>> ceph-users at lists.ceph.com >>>>>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >>>>> >>>>> >>>>> >>>>> -- >>>>> Best Regards, >>>>> >>>>> Wheat >>>> >>>> >>>> >> >> >> -- Best Regards, Wheat
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