找到volume的掛載位置
1、 查看虛機的host和instance_id：
[root@node1 kolla]# nova show 875176b8-5c30-4114-b1f7-33a457c2c933
2、在node1蜻牢，用virsh工具查看磁盤掛載位置：
(nova-compute)[root@node1 /]# virsh dumpxml instance-00000012
得到掛載位置：
/dev/disk/by-path/ip-172.24.3.180:3260-iscsi-iqn.1992-08.com.netapp:sn.2d72abb030d511e7875800a098ac0ce9:vs.24-lun-1
寫磁盤
1煮嫌、 用xxd工具（安裝vim即可使用）檢查磁盤內(nèi)容，二進制轉(zhuǎn)十六進制：
[root@localhost ]# xxd --help
Usage:
xxd [options] [infile [outfile]]
or
xxd -r [-s [-]offset] [-c cols] [-ps] [infile [outfile]]
Options:
-a toggle autoskip: A single '*' replaces nul-lines. Default off.
-b binary digit dump (incompatible with -p,-i,-r). Default hex.
-c cols format <cols> octets per line. Default 16 (-i: 12, -ps: 30).
-E show characters in EBCDIC. Default ASCII.
-g number of octets per group in normal output. Default 2. 每個goup的字節(jié)數(shù)，默認為2刷钢，可設(shè)置伴澄。
-h print this summary.
-i output in C include file style. ：輸出為c包含文件的風(fēng)格荆针，數(shù)組方式存在祭犯。
-l len stop after <len> octets. ：轉(zhuǎn)換到len個字節(jié)后停止轉(zhuǎn)換沃粗。
-ps output in postscript plain hexdump style.
-r reverse operation: convert (or patch) hexdump into binary.
-r -s off revert with <off> added to file positions found in hexdump.
-s [+][-]seek start at <seek> bytes abs. (or +: rel.) infile offset.
-u use upper case hex letters. ： 字節(jié)大寫方式
-v show version: "xxd V1.10 27oct98 by Juergen Weigert".
2、 用dd指令把2M的塊寫滿：
[ubuntu@localhost by-path]$ sudo dd if=/dev/urandom of=../../sde bs=1024 count=2
2+0 records in
2+0 records out
2048 bytes (2.0 kB) copied, 0.00195619 s, 1.0 MB/s
檢查：
(cinder-backup)[root@node1 by-path]# xxd -g 1 -i -u -l 100 ../../sde
unsigned char ______sdcn[] = {
0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00,
0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00,
0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00,
0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00,
0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00,
0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00,
0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00,
0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00, 0X00,
0X00, 0X00, 0X00, 0X00
};
已經(jīng)寫入數(shù)據(jù):
[ubuntu@localhost by-path]$ sudo xxd -g 1 -i -u -l 100 ../../sde
unsigned char ______sde[] = {
0XE5, 0XB2, 0X21, 0X81, 0XD0, 0X55, 0X22, 0XBA, 0X36, 0X2A, 0XA5, 0XF1,
0X12, 0X00, 0XB1, 0X81, 0X62, 0X60, 0X94, 0XE6, 0X05, 0XAC, 0X28, 0XF9,
0XC4, 0X1B, 0XB7, 0X6F, 0X6E, 0X1D, 0XF7, 0XA8, 0XE3, 0X5B, 0X0C, 0XD2,
0X6B, 0X50, 0X47, 0X60, 0XC8, 0X35, 0X37, 0X9A, 0X52, 0XC9, 0X4C, 0XE4,
0X46, 0X9B, 0X72, 0X51, 0XC1, 0XE7, 0X03, 0XED, 0X5C, 0XA7, 0X4D, 0X49,
0X90, 0XAC, 0X3D, 0X8E, 0XE9, 0X9E, 0XCD, 0X0A, 0X63, 0X77, 0X39, 0X52,
0X11, 0XBD, 0XE9, 0XC7, 0XC3, 0X74, 0X04, 0X37, 0X27, 0X8B, 0X85, 0XD8,
0X77, 0X6B, 0X6F, 0XE1, 0X96, 0XBC, 0X2D, 0XD6, 0XC2, 0X19, 0XFB, 0XC9,
0XDA, 0X55, 0X0E, 0XF3
};
unsigned int ______sde_len = 100;
截取程序里讀取磁盤的內(nèi)容
cinder\backup\chunkeddriver.py
增加方法：
def wangyue_write_file(self, usage, content, backup_id):
base_path = '/var/lib/cinder/wangyue/'
if not os.path.exists(base_path):
os.mkdir(base_path)
file_name = base_path + usage + backup_id + '.txt'
with open(file_name, 'a') as f:
f.write(content)
f.write('\n')
修改方法cinder.backup.chunkeddriver.ChunkedBackupDriver#backup：
<!--省略-->
wangyue_time = 1
while True:
backup = objects.Backup.get_by_id(self.context, backup.id)
if backup.status in (fields.BackupStatus.DELETING,
fields.BackupStatus.DELETED):
is_backup_canceled = True
# To avoid the chunk left when deletion complete, need to
# clean up the object of chunk again.
self.delete(backup)
LOG.debug('Cancel the backup process of %s.', backup.id)
break
data_offset = volume_file.tell()
data = volume_file.read(self.chunk_size_bytes)
if wangyue_time == 1:
self.wangyue_write_file('backup_', data[0:10000], backup.id)
wangyue_time = 0
截取磁盤的前10000字節(jié)存在文件backup_${backup_id} 文件：
可以看到都是0x00激挪，磁盤是空的宛篇！
需要驗證下是不是Iscsi掛載有問題
讓程序延遲斷開Iscsi連接
從代碼 cinder\backup\manager.py#_run_backup 知道偷卧，創(chuàng)建備份的過程是：
- 對源卷volume創(chuàng)建Iscsi連接
- 對卷備份
- 關(guān)閉連接
我們在備份之后，加個延時斷連：
def _run_backup(self, context, backup, volume):
backup_service = self.service.get_backup_driver(context)
properties = utils.brick_get_connector_properties()
try:
backup_device = self.volume_rpcapi.get_backup_device(context,
backup,
volume)
attach_info = self._attach_device(context,
backup_device.device_obj,
properties,
backup_device.is_snapshot)
try:
device_path = attach_info['device']['path']
if isinstance(device_path, six.string_types):
if backup_device.secure_enabled:
with open(device_path) as device_file:
backup_service.backup(backup, device_file)
else:
with utils.temporary_chown(device_path):
with open(device_path) as device_file:
backup_service.backup(backup, device_file)
# device_path is already file-like so no need to open it
else:
backup_service.backup(backup, device_path)
LOG.debug('==========waite 6 mins, begin===========')
import time
time.sleep(360)
LOG.debug('==========waite 6 mins, end===========')
這樣，在中斷的時間內(nèi)，我們可以驗證下Iscsi是否掛載成功：
1掌逛、netapp 管理平臺檢查lun是否已經(jīng)連接上
2动知、根據(jù)cinder-backup.log盒粮，知道原卷臨時掛載在/dev/disk/by-path/ip-172.24.3.180:3260-iscsi-iqn.1992-08.com.netapp:sn.2d72abb030d511e7875800a098ac0ce9:vs.24-lun-0目錄妒穴， xxd檢查發(fā)現(xiàn)內(nèi)容都是X00, 0X00, 0X00, 0X00，說明是個空卷，不是原卷真正的內(nèi)容。
node1 2017-07-13 16:16:05.050 6 DEBUG os_brick.initiator.connectors.iscsi [req-54e3c2dd-46f6-4e3d-894f-211af2fde587 1a236a63e6864cf5a5b26d4b816f719b 406cd353135e44f0ade98f53d92d5d8b - default default] Found iSCSI node [u'/dev/disk/by-path/ip-172.24.3.180:3260-iscsi-iqn.1992-08.com.netapp:sn.2d72abb030d511e7875800a098ac0ce9:vs.24-lun-0'] (after 1 rescans) connect_volume /var/lib/kolla/venv/lib/python2.7/site-packages/os_brick/initiator/connectors/iscsi.py:452
3啸箫、那我們試著在隨便某臺主機手動掛載卷（root權(quán)限）：
（1） 發(fā)現(xiàn)目標
[root@node1 ~]# iscsiadm -m discovery -t st -p 172.24.3.180
172.24.3.180:3260,1057 iqn.1992-08.com.netapp:sn.2d72abb030d511e7875800a098ac0ce9:vs.24
172.24.3.181:3260,1058 iqn.1992-08.com.netapp:sn.2d72abb030d511e7875800a098ac0ce9:vs.24
（2） 獲得本機iqn
[root@node1 ~]# cat /etc/iscsi/initiatorname.iscsi
InitiatorName=iqn.1994-05.com.redhat:cad0246c576
（3） netapp管理界面，把iqn添加到lun啟動程序里召川，下拉框內(nèi)選擇，然后點擊“添加啟動程序”逗威，保存退出
（4） login Iscsi
[root@node1 ~]# iscsiadm -m node -p 172.24.3.180 -l
Logging in to [iface: default, target: iqn.1992-08.com.netapp:sn.2d72abb030d511e7875800a098ac0ce9:vs.24, portal: 172.24.3.180,3260] (multiple)
Login to [iface: default, target: iqn.1992-08.com.netapp:sn.2d72abb030d511e7875800a098ac0ce9:vs.24, portal: 172.24.3.180,3260] successful.
（5） 檢查內(nèi)容不是空
那就奇怪了，怎么程序掛載的卷和我們手動掛載的卷，內(nèi)容不一樣呢？期奔？
用inspect指令檢查容器配置
docker inspect cinder_volume
docker inspect cinder_backup
做對比
發(fā)現(xiàn)cinder_backup少了Iscsi_info谊娇，是不是缺少這個就無法正常使用Iscsi赠堵，導(dǎo)致Iscsi卷掛載讀取內(nèi)容為空？
檢查kolla-ansible的配置文件 /usr/share/kolla-ansible/ansible/roles/cinder/defaults/main.yml
改成：
重新部署 kolla-ansible reconfigure -i ~/multinode -t cinder
再測試備份還原就正常了Ｄ湃！！
