[Kimchi-devel] [RFC] Create logical pool from existing VG

[Aline Manera]

On 15/10/2015 14:35, Suresh Babu Angadi wrote:
>
>
> On 10/15/2015 10:30 PM, Jose Ricardo Ziviani wrote:
>>
>>
>> On 15-10-2015 13:12, Aline Manera wrote:
>>>
>>>
>>> On 15/10/2015 12:00, Jose Ricardo Ziviani wrote:
>>>>
>>>>
>>>> On 15-10-2015 11:56, Aline Manera wrote:
>>>>>
>>>>>
>>>>> On 15/10/2015 11:45, Jose Ricardo Ziviani wrote:
>>>>>> Hello,
>>>>>>
>>>>>> I'm about to write a new feature to Kimchi. It will allow users to
>>>>>> define any existing volume group as a storage pool, where guests 
>>>>>> will
>>>>>> be able to create logical volumes into it. NOTE: VGs already in 
>>>>>> use as
>>>>>> storage pool won't be listed.
>>>>>>
>>>>>> I read Pooja's "[RFC] Proposal to manage Physical Volumes on 
>>>>>> Ginger",
>>>>>> and now I think all LVM code should be implemented in WOK so both
>>>>>> plugins (Kimchi/Ginger) could take advantages from that.
>>>>>>
> I believe the idea was to have "wok" as base framework without having 
> any functionality implemented.

Yeap! Wok is only a basic web server! And it should not have those kind 
of features.

>>>>>> API:
>>>>>>
>>>>>> Collection: /plugins/kimchi/host/vgs
>>>>>> Method: GET
>>>>>> Returns: list of vgnames:
>>>>>> [vgname1, vgname2]
>>>>>>
>>>>>
>>>>> ACK
>>>>>
>>>>>> Resource: /plugins/kimchi/host/vg/vgname
>>>>>> Method: GET
>>>>>> Returns: dict
>>>>>> { vgname, size, free_size, [PV partition list, like: sda4, sdb3], 
>>>>>> [LV
>>>>>> name list, like: lv_root] }
>>>>>>
>>>>>
>>>>> ACK
>>>>>
>>>>>> Resource: /plugins/kimchi/storagepools/vgname
>>>>>> Method: POST
>>>>>> data: { vgname, storagepool_name, type=logical }
>>>>>
>>>>> I am little bit confused with this API. Usually the POST is done in a
>>>>> Collection so, something like:
>>>>>
>>>>> POST /plugins/kimchi/storagepools {name: pool_name, type: logical,
>>>>> vgname: vg_name}
>>>>>
>>>>> Is that what you are proposing?
>>>>
>>>> yes! updating:
>>>>
>>>> Collection: /plugins/kimchi/storagepools
>>>> Method: POST
>>>> data: {name: pool_name, type: logical, vgname: vg_name}
>>>>
>>>>>
>>>>>>
>>>>>> The frontend, I think we could have a table indicating all available
>>>>>> devices available for a logical storage pool, for example:
>>>>>>
>>>>>>
>>>>>> Define a New Storage Pool
>>>>>> 1. Storage Pool Name
>>>>>> +-----------------------------------------+
>>>>>> | mypool                                  |
>>>>>> +-----------------------------------------+
>>>>>> The name used to identify the storage pools, and it should not be
>>>>>> empty.
>>>>>>
>>>>>> 2. Storage Pool Type
>>>>>> +-----------+
>>>>>> | LOGICAL   |
>>>>>> +-----------+
>>>>>>
>>>>>> 3. Device path
>>>>>> +-------+-------+---------------+---------------+
>>>>>> |       |device | size        | free size    |
>>>>>> +-------+-------+---------------+---------------+
>>>>>> | ()     | sdb    | 50 GiB    | 50 GiB    |
>>>>>> +-------+-------+---------------+---------------+
>>>>>> | ()     | sdc    | 10 GiB    | 8 GiB        |
>>>>>> +-------+-------+---------------+---------------+
>>>>>> | ()    | vg_a    | 20 GiB    | 18 GiB    |
>>>>>> +-------+-------+---------------+---------------+
>>>>>>
>>>>>> +--------+
>>>>>> | Create |
>>>>>> +--------+
>>>>>
>>>>> May user select multiple VGs to create a logical pool? Or is it 
>>>>> restrict
>>>>> to one by one, one VG, one logical pool?
>>>>> Depending on that, we need to redesign the UI
>>>>
>>>> Nope, my initial idea is to have 1 device to 1 storage pool. That's is
>>>> because users can group many partitions (PVs) into one VG.
>>>
>>> So I suggest to have separated options: one to create a logical pool
>>> from raw disks and other one to create a logical pool from an 
>>> existing VG.
>>
>>
>> I see, so we will have:
>>
>> 2. Storage Pool Type
>> +--------------------------+
>> | (snip)
>> | LOGICAL                  |
>> | LOGICAL FROM EXISTING VG |
>> | (snip)                   |
>> +--------------------------+
>>
>> and, suppose 'LOGICAL FROM EXISTING VG' is selected
>>
>> +-------+---------------+---------------+---------------+
>> |    | device    | size        | free size    |
>> +-------+---------------+---------------+---------------+
>> |  ()   | vg_a          | 20 GiB    | 18 GiB    |
>> |  ()   | vg_b        | 10 GiB    | 5 GiB        |
>> +-------+---------------+---------------+---------------+
>>
>> Any other pool type will keep unchanged.
>>
>> Note: I intend to not list VGs without free space available. What do 
>> you think?
>>>
>>>>
>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> Kimchi-devel mailing list
>>>>>> Kimchi-devel at ovirt.org
>>>>>> http://lists.ovirt.org/mailman/listinfo/kimchi-devel
>>>>>>
>>>>>
>>>>
>>>
>>
>