Re: Ho to identify location of Primary Copy Of Obj ?

[Dan Mick <dan.mick@inktank.com>]

Ah, yeah, that assumption would be a problem.

So, Hemant, does
	ceph osd dump <poolname> <objectname>

show you information that makes sense?

On 09/26/2012 08:21 AM, Sage Weil wrote:
> On Wed, 26 Sep 2012, hemant surale wrote:
>> Hi Dan ,
>>       I have set replication factor to 3 of pool 'newbyh' . Then when i
>> tried to execute cmds told by you I got that it reported like
>>
>> ----------------------------------------------------
>> root@third-virtual-machine:~# osdmaptool --test-map-object Obj1 osdmap
>> osdmaptool: osdmap file 'osdmap'
>>   object 'Obj1' -> 0.c3c4 -> [0,1]
>> -----------------------------------------------------
>>
>> I even checked manually the dirs at every node . it shows proper data
>> available within osd0,osd1 & osd2 . ( i hve 3 node cluster using VM
>> Ceph v0.36 )
>>
>> So my questions is why in above execution it shows that Obj1 is at
>> [0,1] .. it should report all nodes like [0,1,2] .
>
> The --test-map-object is currently somewhat useless because it assumes
> pool 0 ('data'), and your object is probably in a different pool.
>
> sage
>
>>
>>
>>
>> -
>> Hemant Surale.
>>
>> On Wed, Sep 26, 2012 at 2:04 AM, Dan Mick <dan.mick@inktank.com> wrote:
>>> Hemant:
>>>
>>> Yes, you can.  Use ceph osd getmap -o <file> to get the OSD map, and then
>>> use osdmaptool --find-object-map <objectname> <file> to output the
>>> PG the object hashes to and the list of OSDs that PG maps to (primary
>>> first):
>>>
>>> $ ceph osd getmap -o osdmap
>>> got osdmap epoch 59
>>> $ osdmaptool --test-map-object dmick.rbd osdmap
>>> osdmaptool: osdmap file 'osdmap'
>>>   object 'dmick.rbd' -> 0.69c8 -> [3,1]
>>>
>>> shows dmick.rbd mapping to pg 0.69c8, which in turn maps to OSDs 3 and 1, 3
>>> being the primary.
>>>
>>>
>>> On 09/25/2012 02:30 AM, hemant surale wrote:
>>>>
>>>> Hi Community,
>>>>             Is it possible to identify where exactly primary copy of obj
>>>> is stored ? I am using crushmaps to use specific osds for data
>>>> placement but i want to knw the primary capoy location. Or I need to
>>>> replace pseudo random function by some deterministic function to guide
>>>> ceph to utilize specific osd?
>>>>
>>>>
>>>> Regards,
>>>> Hemant Surale.
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>>>
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