Re: 答复: how to see file object-mappings for cephfuse client

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On Mon, Dec 7, 2015 at 1:52 PM, Wuxiangwei <wuxiangwei@xxxxxxx> wrote:
> Thanks Yan, what if we wanna see some more specific or detailed information? E.g. with cephfs we may run 'cephfs /mnt/a.txt show_location --offset' to find the location of a given offset.
>

When using default layout, object size is 4M, (offset / 4194304) is
subfix of object name. For example. offset 0 is located in object
<inode number in hex>.00000000, offset 4194304 is located in object
<inode number in hex>.0000001.

For fancy layout, please read
http://docs.ceph.com/docs/master/dev/file-striping/

> -----------------------
> Wu Xiangwei
> Tel : 0571-86760875
> 2014 UIS 2, TEAM BORE
>
>
> -----邮件原件-----
> 发件人: Yan, Zheng [mailto:ukernel@xxxxxxxxx]
> 发送时间: 2015年12月7日 11:22
> 收件人: wuxiangwei 09660 (RD)
> 抄送: ceph-devel@xxxxxxxxxxxxxxx; ceph-users@xxxxxxxxxxxxxx
> 主题: Re: how to see file object-mappings for cephfuse client
>
> On Mon, Dec 7, 2015 at 10:51 AM, Wuxiangwei <wuxiangwei@xxxxxxx> wrote:
>> Hi, Everyone
>>
>> Recently I'm trying to figure out how to use ceph-fuse. If we mount cephfs as the kernel client, there is a 'cephfs' command tool (though it seems to be 'deprecated') with 'map' and 'show_location' commands to show the RADOS objects belonging to a given file. However, it doesn't work well for ceph-fuse, neither can I find a similar tool to see the mappings. Any suggestions?
>> Thank you!
>
> Rados objects  for a give inode is in form <inode number in hex>.xxxxxxxx.
>
> To get a file's layout, you can use getfattr -n ceph.file.layout <file name>
>
> To find a given object is stored on which OSDs, you can use command, ceph osd map <cephfs data pool> <object name>
>
>>
>>
>> -----------------------
>> Wu Xiangwei
>> Tel : 0571-86760875
>> 2014 UIS 2, TEAM BORE
>>
>> --
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