Re: testing the /dev/cciss/c0d0 device names

[Ilya Dryomov]

On Sat, Dec 5, 2015 at 7:36 PM, Loic Dachary  wrote:
> Hi Ilya,
>
> ceph-disk has special handling for device names like /dev/cciss/c0d1 [1] and 
> it was partially broken when support for device mapper was introduced. 
> Ideally there would be a way to test that support when running the ceph-disk 
> suite [2]. Do you know of a way to do that without having the hardware for 
> which this driver is designed ?
>
> Maybe this convention (/dev/cciss/c0d0 being mapped to /sys/block/cciss!c0d0 
> is not unique to this driver and I could use another to validate the name 
> conversion from X/Y to X!Y and vice versa is handled as it should ?

No, it's not unique.  driver core does strreplace(s, '/', '!') at
register time to work around such block devices.  The list includes
DAC960, aoeblk, cciss, cpqarray, sx8 and probably more, but I don't
think anything widespread uses this naming scheme.  IIRC dm actually
won't let you name a device with anything that contains a slash.

If you really wanted you could set up aoeblk I guess, but a simple unit
test should be be more than enough ;)

Thanks,

Ilya
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how to see file object-mappings for cephfuse client

[Wuxiangwei]

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!


---
Wu Xiangwei
Tel : 0571-86760875
2014 UIS 2, TEAM BORE

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

[Yan, Zheng]

On Mon, Dec 7, 2015 at 10:51 AM, Wuxiangwei  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 ..

To get a file's layout, you can use getfattr -n ceph.file.layout 

To find a given object is stored on which OSDs, you can use command,
ceph osd map  

>
>
> ---
> Wu Xiangwei
> Tel : 0571-86760875
> 2014 UIS 2, TEAM BORE
>
> --
> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
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答复: how to see file object-mappings for cephfuse client

[Wuxiangwei]

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.

---
Wu Xiangwei
Tel : 0571-86760875
2014 UIS 2, TEAM BORE


-邮件原件-
发件人: Yan, Zheng [mailto:uker...@gmail.com] 
发送时间: 2015年12月7日 11:22
收件人: wuxiangwei 09660 (RD)
抄送: ceph-devel@vger.kernel.org; ceph-us...@lists.ceph.com
主题: Re: how to see file object-mappings for cephfuse client

On Mon, Dec 7, 2015 at 10:51 AM, Wuxiangwei  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 ..

To get a file's layout, you can use getfattr -n ceph.file.layout 

To find a given object is stored on which OSDs, you can use command, ceph osd 
map  

>
>
> ---
> Wu Xiangwei
> Tel : 0571-86760875
> 2014 UIS 2, TEAM BORE
>
> --
> To unsubscribe from this list: send the line "unsubscribe ceph-devel" 
> in the body of a message to majord...@vger.kernel.org More majordomo 
> info at  http://vger.kernel.org/majordomo-info.html