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Issue with storage and Centos Atomic Host

asked 2016-08-04 09:04:56 +0000

Damien gravatar image

Hi all,

I am not an expert in LVM volumes but I am trying to follow the "Setting Up Storage" article. I am using Centos Atomic Host on VMWare. I have installed the OS with no specific configuration. If I have a look at the docker configuration :

 Containers: 0
 Running: 0
 Paused: 0
 Stopped: 0
Images: 0
Server Version: 1.10.3
Storage Driver: devicemapper
 Pool Name: cah-docker--pool
 Pool Blocksize: 524.3 kB
 Base Device Size: 10.74 GB
 Backing Filesystem: xfs
 Data file:
 Metadata file:
 Data Space Used: 20.45 MB
 Data Space Total: 25.18 GB
 Data Space Available: 25.16 GB
 Metadata Space Used: 53.25 kB
 Metadata Space Total: 71.3 MB
 Metadata Space Available: 71.25 MB
 Udev Sync Supported: true
 Deferred Removal Enabled: true
 Deferred Deletion Enabled: true
 Deferred Deleted Device Count: 0
 Library Version: 1.02.107-RHEL7 (2016-06-09)
Execution Driver: native-0.2
Logging Driver: journald
 Volume: local
 Network: host bridge null
Kernel Version: 3.10.0-327.22.2.el7.x86_64
Operating System: CentOS Linux 7 (Core)
OSType: linux
Architecture: x86_64
Number of Docker Hooks: 2
CPUs: 1
Total Memory: 1.797 GiB
Name: atomic-test
WARNING: bridge-nf-call-iptables is disabled
WARNING: bridge-nf-call-ip6tables is disabled
Registries: docker.io (secure)

Then of course, I want to attach a new disk and increase the capacity of the host to store docker images.

-bash-4.2# fdisk -l

    -bash-4.2# fdisk -l

Disk /dev/sda: 68.7 GB, 68719476736 bytes, 134217728 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x0003fc26

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048      616447      307200   83  Linux
/dev/sda2          616448   134217727    66800640   8e  Linux LVM

Disk /dev/sdb: 34.4 GB, 34359738368 bytes, 67108864 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Seems good to me. Then I add the new disk in the docker-storage-setup:


And execute the script:

-bash-4.2# docker-storage-setup
Checking that no-one is using this disk right now ...

Disk /dev/sdb: 32768 cylinders, 64 heads, 32 sectors/track
sfdisk:  /dev/sdb: unrecognized partition table type

Old situation:
sfdisk: No partitions found

New situation:
Units: sectors of 512 bytes, counting from 0

   Device Boot    Start       End   #sectors  Id  System
/dev/sdb1          2048  67108863   67106816  8e  Linux LVM
/dev/sdb2             0         -          0   0  Empty
/dev/sdb3             0         -          0   0  Empty
/dev/sdb4             0         -          0   0  Empty
Warning: no primary partition is marked bootable (active)
This does not matter for LILO, but the DOS MBR will not boot this disk.
Successfully wrote the new partition table

Re-reading the partition table ...

If you created or changed a DOS partition, /dev/foo7, say, then use dd(1)
to zero the first 512 bytes:  dd if=/dev/zero ...
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answered 2016-08-11 10:52:18 +0000

Thabend0r gravatar image

I had the same experience.. when you add a new device to the docker storage pool, docker won't actually use the space until it needs more extends ( thin pool)

but there is one line in the docker info that will show you if the space has been added. look for the line "Base Device Size" This will show you the space available in your docker storage pool



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Thanks a lot Paul for your explanation !

Damien ( 2016-08-16 06:52:57 +0000 )edit

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Asked: 2016-08-04 09:04:56 +0000

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Last updated: Aug 11 '16