[sheepdog] Redundancy policy via iSCSI

[hujianyang]

Hi Hitoshi,

Sorry for disturb.

I'm testing redundancy policy of sheepdog via iSCSI. I think
if I create a 1G v-disk, the total space cost of this device
should be 3*1G under a 3 copies policy. But after tests, I
find the cost of this device is only 1G. Seems no additional
copy is created.

I don't know what happened. I'd like to should my configurations
and wish you could take some time to help me. Many thanks!


linux-rme9:/mnt # dog cluster info
Cluster status: running, auto-recovery enabled

Cluster created at Tue Feb  3 23:07:13 2015

Epoch Time           Version [Host:Port:V-Nodes,,,]
2015-02-03 23:07:13      1 [130.1.0.147:7000:128, 130.1.0.148:7000:128, 130.1.0.149:7000:128]
linux-rme9:/mnt # dog node list
  Id   Host:Port         V-Nodes       Zone
   0   130.1.0.147:7000    	128          0
   1   130.1.0.148:7000    	128          0
   2   130.1.0.149:7000    	128          0
linux-rme9:/mnt # dog vdi list
  Name        Id    Size    Used  Shared    Creation time   VDI id  Copies  Tag   Block Size Shift
  Hu0          0  1.0 GB  1.0 GB  0.0 MB 2015-02-03 23:12   6e7762      3                22
linux-rme9:/mnt # dog node info
Id	Size	Used	Avail	Use%
 0	261 GB	368 MB	260 GB	  0%
 1	261 GB	336 MB	261 GB	  0%
 2	261 GB	320 MB	261 GB	  0%
Total	783 GB	1.0 GB	782 GB	  0%

Total virtual image size	1.0 GB

linux-rme9:/mnt # tgtadm --op show --mode target
Target 1: iqn.2015.01.org.sheepdog
    System information:
        Driver: iscsi
        State: ready
    I_T nexus information:
        I_T nexus: 3
            Initiator: iqn.1996-04.de.suse:01:23a8f73738e7 alias: Fs-Server
            Connection: 0
                IP Address: 130.1.0.10
    LUN information:
        LUN: 0
            Type: controller
            SCSI ID: IET     00010000
            SCSI SN: beaf10
            Size: 0 MB, Block size: 1
            Online: Yes
            Removable media: No
            Prevent removal: No
            Readonly: No
            SWP: No
            Thin-provisioning: No
            Backing store type: null
            Backing store path: None
            Backing store flags:
        LUN: 1
            Type: disk
            SCSI ID: IET     00010001
            SCSI SN: beaf11
            Size: 1074 MB, Block size: 512
            Online: Yes
            Removable media: No
            Prevent removal: No
            Readonly: No
            SWP: No
            Thin-provisioning: No
            Backing store type: sheepdog
            Backing store path: tcp:130.1.0.147:7000:Hu0
            Backing store flags:
    Account information:
    ACL information:
        ALL


Client:
 # iscsiadm -m node --targetname iqn.2015.01.org.sheepdog --portal 130.1.0.147:3260 --rescan
Rescanning session [sid: 4, target: iqn.2015.01.org.sheepdog, portal: 130.1.0.147,3260]
 # dd if=/dev/random of=/dev/sdg bs=2M
dd: writing `/dev/sdg': No space left on device
0+13611539 records in
0+13611538 records out
1073741824 bytes (1.1 GB) copied, 956.511 s, 1.1 MB/s

Thanks!
Hu