Unable to update OSD journal size

[Maria Yousaf]

Brief Description
-----------------
Unable to update size of journal on an OSD using CLI or horizon.

Severity
--------
Major

Steps to Reproduce
------------------
1. Run the following:
[wrsroot@controller-0 ~(keystone_admin)]$ system host-stor-list storage-3
+--------------------------------------+----------+-------+--------------+--------------------------------------+------------------------------------------------------ -----------------+--------------+------------------+-----------+
| uuid | function | osdid | capabilities | idisk_uuid | journal_path | journal_node | journal_size_gib | tier_name |
+--------------------------------------+----------+-------+--------------+--------------------------------------+------------------------------------------------------ -----------------+--------------+------------------+-----------+
| 46945964-a455-4b1f-bafb-ea3619837bb4 | osd | 2 | {} | 1a34f97a-faad-4016-924a-8cad4a022ac2 | /dev/disk/by-path/pci-0000:03:00.0-sas-0x5001e67d3cb4 d000-lun-0-part2 | /dev/sda2 | 1 | storage |
+--------------------------------------+----------+-------+--------------+--------------------------------------+------------------------------------------------------ -----------------+--------------+------------------+-----------+

2. [wrsroot@controller-0 ~(keystone_admin)]$ system host-stor-update --journal-location 46945964-a455-4b1f-bafb-ea3619837bb4 --journal-size 2 46945964-a455-4b1f-bafb-ea36 19837bb4
Invalid update: Size of collocated journal is fixed.

Also note that units are wrong in the help text:

[wrsroot@controller-0 ~(keystone_admin)]$ system host-stor-update
usage: system host-stor-update [--journal-location [<journal_location>]]
                               [--journal-size [<size of the journal MiB>]]
                               <osd stor uuid>
system host-stor-update: error: too few arguments

Command actually takes gib rather than mib.

If the user tries the same action using horizon:
1. Lock storage node
2. The Edit button is greyed out

Lastly, when initially adding a new OSD, the journal size is fixed at 1024 MiB.

Expected Behavior
------------------
1. User should be able to update size of journal via CLI or Horizon
2. Help text should be correct
3. User should be able to add a new OSD with the desired journal size
4. Units should be displayed consistently (MiB vs GiB)

Actual Behavior
----------------
Updating journal size is rejected

Reproducibility
---------------
100%

System Configuration
--------------------
Storage

Branch/Pull Time/Commit
-----------------------
StarlingX master as of 2018-10-09_01-52-01

[Ghada Khalil (gkhalil)]

Targeting stx.2019.03 - specific to updating journal sizes (default size works). Therefore, not required for stx.2018.10

[yong hu (yhu6)]

According to the output of "system host-stor-list storage-3", on storage-3, there is only one OSD function, NO dedicated "journal" function exists. And *by design*: If no journal function is configured on the host, then the Journal is set to Collocated with OSD, and the Journal Size is set to a default value. These settings cannot be changed.

In addition, if storage node has the 3rd disk partition, this command line can be used to add a "journal" function by:
#system host-stor-add host_name journal device_uuid

and then update journal size (in MB) by following command, in which journal_function_uuid is different from osd_uuid:
# system host-stor-update osd_uuid --journal-location journal_function_uuid [--journal-size size]

Therefore, host-stor-update is functional for adjusting journal size, with the pre-condition that there is a "journal" function in storage node.
================================================================================================

Last, "Units should be displayed consistently (MiB vs GiB)" is meaningful and valid, and there should be an enhancement to the command line, to make "system host-stor-update" is aligned with "system host-stor-add" and others, all to use GiB for <size of the journal>.