Comment 0 for bug 1776888

I tested the latest bluestore code, it is the patch of Mr Tonezhang:

https://review.openstack.org/#/c/566810/
https://review.openstack.org/#/c/566801/9

1.

In my tests, I encountered a problem that osd bootstrap failed when executing this command:

ceph-osd -i "${OSD_ID}" --mkfs -k "${OSD_DIR}"/keyring --osd-uuid "${OSD_UUID}"

the los as follows:

```
++ partprobe
++ ln -sf /dev/disk/by-partlabel/KOLLA_CEPH_DATA_BS_B_2 /var/lib/ceph/osd/ceph-2/block
++ '[' -n '' ']'
++ '[' -n '' ']'
++ ceph-osd -i 2 --mkfs -k /var/lib/ceph/osd/ceph-2/keyring --osd-uuid b5703869-87d1-4ab8-be11-ab24db2870cc
```

So I add "-d" parameter to debug the problem:
ceph-osd -i -d "${OSD_ID}" --mkfs -k "${OSD_DIR}"/keyring --osd-uuid "${OSD_UUID}"

```
++ ceph-osd -d -i 0 --mkfs -k /var/lib/ceph/osd/ceph-0/keyring --osd-uuid e14d5061-ae41-4c16-bf3c-2e9c5973cb54
2018-06-13 17:29:53.216034 7f808b6a0d80 0 ceph version 12.2.5 (cad919881333ac92274171586c827e01f554a70a) luminous (stable), process (unknown), pid 78
2018-06-13 17:29:53.243358 7f808b6a0d80 0 stack NetworkStack max thread limit is 24, switching to this now. Higher thread values are unnecessary and currently unsupported.
2018-06-13 17:29:53.248479 7f808b6a0d80 1 bluestore(/var/lib/ceph/osd/ceph-0) mkfs path /var/lib/ceph/osd/ceph-0
2018-06-13 17:29:53.248676 7f808b6a0d80 -1 bluestore(/var/lib/ceph/osd/ceph-0/block) _read_bdev_label failed to open /var/lib/ceph/osd/ceph-0/block: (2) No such file or directory
2018-06-13 17:29:53.248714 7f808b6a0d80 -1 bluestore(/var/lib/ceph/osd/ceph-0/block) _read_bdev_label failed to open /var/lib/ceph/osd/ceph-0/block: (2) No such file or directory
2018-06-13 17:29:53.249134 7f808b6a0d80 -1 bluestore(/var/lib/ceph/osd/ceph-0) _read_fsid unparsable uuid
2018-06-13 17:29:53.249141 7f808b6a0d80 1 bluestore(/var/lib/ceph/osd/ceph-0) mkfs using provided fsid e14d5061-ae41-4c16-bf3c-2e9c5973cb54
2018-06-13 17:29:53.249361 7f808b6a0d80 1 bdev create path /var/lib/ceph/osd/ceph-0/block type kernel
2018-06-13 17:29:53.249372 7f808b6a0d80 1 bdev(0x563ef1b19600 /var/lib/ceph/osd/ceph-0/block) open path /var/lib/ceph/osd/ceph-0/block
2018-06-13 17:29:53.249400 7f808b6a0d80 -1 bdev(0x563ef1b19600 /var/lib/ceph/osd/ceph-0/block) open open got: (2) No such file or directory
2018-06-13 17:29:53.249654 7f808b6a0d80 -1 bluestore(/var/lib/ceph/osd/ceph-0) mkfs failed, (2) No such file or directory
2018-06-13 17:29:53.249662 7f808b6a0d80 -1 OSD::mkfs: ObjectStore::mkfs failed with error (2) No such file or directory
2018-06-13 17:29:53.249950 7f808b6a0d80 -1 ** ERROR: error creating empty object store in /var/lib/ceph/osd/ceph-0: (2) No such file or directory
```
After my testing, I found that after executing this command:

```
sgdisk "--change-name=2:KOLLA_CEPH_DATA_BS_B_${OSD_ID}" "--typecode=2:${CEPH_OSD_TYPE_CODE}" -- "${OSD_BS_BLOCK_DEV}"
```
It took 3 seconds to generate the by-partlabel folder and partlabel on my centos virtual machine, but the partuuid was generated immediately without delay.

So I think using partuuid is better than partlabel, when initializing ceph.

In the ceph-deploy tool, the command to initialize osd is 'ceph-disk preapre', which also uses partuuid.

2.

In the current find_disks.py logic, both bluestore and filestore return all disk information, including osd partition, journal partition, block partition, wal partition and db partition.
```
"bs_db_device": "",
"bs_db_label": "",
"bs_db_partition_num": "",
"bs_wal_device": "",
"bs_wal_label": "",
"bs_wal_partition_num": "",
"device": "/dev/xvdb",
"external_journal": false,
"fs_label": "",
"fs_uuid": "cd711f44-2fa8-41c8-8f74-b43e96758edd",
"journal": "",
"journal_device": "",
"journal_num": 0,
"partition": "/dev/xvdb",
"partition_label": "KOLLA_CEPH_OSD_BOOTSTRAP_BS",
"partition_num": "1"
```
There is a bit of confusion here. In fact, in the filestore, there are only osd partition and journal partition. In the bluestore, there are osd data partition, block partition, wal partition and db partition.

I think we should distinguish between the bluestore and filestore disk information.

3.

The osd partition lable after successful initialization is as follows:

```
KOLLA_CEPH_BSDATA_1
KOLLA_CEPH_DATA_BS_B_1
KOLLA_CEPH_DATA_BS_D_1
KOLLA_CEPH_DATA_BS_W_1

```
The prefix is different so we can't find the disk as the filestore's logic.

So I think a good way to name it like this:

```
KOLLA_CEPH_DATA_BS_1
KOLLA_CEPH_DATA_BS_1_B
KOLLA_CEPH_DATA_BS_1_D
KOLLA_CEPH_DATA_BS_1_W
```
Regular naming can reduce some code.