thank you very much, Karan, for your explanation.
Regards
Pragya Jain
On Tuesday, 15 July 2014 1:53 PM, Karan Singh <karan.si...@csc.fi> wrote:
>
>
>Hi Pragya
>
>
>Let me try to answer these.
>
>
>1# The decisions is based on your use case ( performance , reliability ) .If
>you need high performance out of your cluster , the deployer will create a
>pool on SSD and assign this pool to applications which require higher I/O. For
>Ex : if you integrate openstack with Ceph , you can instruct openstack
>configuration files to write data to a specific ceph pool.
>(http://ceph.com/docs/master/rbd/rbd-openstack/#configuring-glance) ,
>similarly you can instruct CephFS and RadosGW with pool to use for data
>storage.
>
>
>2# Usually the end user (client to ceph cluster) does not bother about where
>the data is getting stored , which pool its using , and what is the real
>physical locate of data. End user will demand for specific performance ,
>reliability and availability. It is the job of Ceph admin to fulfil their
>storage requirements, out of Ceph functionalities of SSD , Erausre codes ,
>replication level etc.
>
>
>
>
>Block Device :- End user will instruct the application ( Qemu / KVM ,
>OpenStack etc ) , which pool it should for data storage. rbd is the default
>pool for block device.
>CephFS :- End user will mount this pool as filesystem and can use further.
>Default pool are data and metadata .
> RadosGW :- End user will storage objects using S3 or Swift API.
>
>
>
>
>
>- Karan Singh -
>
>On 15 Jul 2014, at 07:42, pragya jain <prag_2...@yahoo.co.in> wrote:
>
>thank you very much, Craig, for your clear explanation against my questions.
>>
>>
>>Now I am very clear about the concept of pools in ceph.
>>
>>
>>But I have two small questions:
>>1. How does the deployer decide that a particular type of information will be
>>stored in a particular pool? Are there any settings at the time of creation
>>of pool that a deployer should make to ensure that which type of data will be
>>stored in which pool?
>>
>>
>>2. How does an end-user specify that his/her data will be stored in which
>>pool? how can an end-user come to know which pools are stored on SSDs or on
>>HDDs, what are the properties of a particular pool?
>>
>>
>>Thanks again, Please help to clear these confusions also.
>>
>>
>>Regards
>>Pragya Jain
>>
>>
>>
>>On Sunday, 13 July 2014 5:04 AM, Craig Lewis <cle...@centraldesktop.com>
>>wrote:
>>
>>
>>>
>>>
>>>I'll answer out of order.
>>>
>>>
>>>#2: rdb is used for RDB images. data and metadata are used by CephFS.
>>>RadosGW's default pools will be created the first time radosgw starts up.
>>>If you aren't using RDB or CephFS, you can ignore those pools.
>>>
>>>
>>>#1: RadosGW will use several pools to segregate it's data. There are a
>>>couple pools for store user/subuser information, as well as pools for
>>>storing the actual data. I'm using federation, and I have a total of 18
>>>pools that RadosGW is using in some form. Pools are a way to logically
>>>separate your data, and pools can also have different replication/storage
>>>settings. For example, I could say that the .rgw.buckets.index pool needs
>>>4x replication and is only stored on SSDs, while .rgw.bucket is 3x
>>>replication on HDDs.
>>>
>>>
>>>#3: In addition to #1, you can setup different pools to actually store user
>>>data in RadosGW. For example, an end user may have some very important data
>>>that you want replicated 4 times, and some other data that needs to be
>>>stored on SSDs for low latency. Using CRUSH, you would create the some
>>>rados pools with those specs. Then you'd setup some placement targets in
>>>RadosGW that use those pools. A user that cares will specify a placement
>>>target when they create a bucket. That way they can decide what the storage
>>>requirements are. If they don't care, then they can just use the default.
>>>
>>>
>>>Does that help?
>>>
>>>
>>>
>>>
>>>
>>>On Thu, Jul 10, 2014 at 11:34 PM, pragya jain <prag_2...@yahoo.co.in> wrote:
>>>
>>>hi all,
>>>>
>>>>
>>>>I have some very basic questions about pools in ceph.
>>>>
>>>>
>>>>According to ceph documentation, as we deploy a ceph cluster with radosgw
>>>>instance over it, ceph creates pool by default to store the data or the
>>>>deployer can also create pools according to the requirement.
>>>>
>>>>
>>>>Now, my question is:
>>>>1. what is the relevance of multiple pools in a cluster?
>>>>i.e. why should a deployer create multiple pools in a cluster? what should
>>>>be the benefits of creating multiple pools?
>>>>
>>>>
>>>>2. according to the docs, the default pools are data, metadata, and rbd.
>>>>what is the difference among these three types of pools?
>>>>
>>>>
>>>>3. when a system deployer has deployed a ceph cluster with radosgw
>>>>interface and start providing services to the end-user, such as, end-user
>>>>can create their account on the ceph cluster and can store/retrieve their
>>>>data to/from the cluster, then Is the end user has any concern about the
>>>>pools created in the cluster?
>>>>
>>>>
>>>>Please somebody help me to clear these confusions.
>>>>
>>>>
>>>>regards
>>>>Pragya Jain
>>>>_______________________________________________
>>>>ceph-users mailing list
>>>>ceph-users@lists.ceph.com
>>>>http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
>>>>
>>>>
>>>
>>>
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>>ceph-users@lists.ceph.com
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>>
>
>
>
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