issue with mounting an EBS volume

From: sebastian rooks <no email>
Date: Thu, 14 Jul 2011 18:28:36 +0200

Hi Justin,

First of all, thank you for StarCluster.

I am trying to set up a custom hvm AMI based on Ubuntu Natty. I
managed to get to the point where I get a cluster running with SGE and
OpenMPI.
But I have got an issue with mounting an EBS volume before sharing it as NFS.
The cluster definition is:

  [cluster computecluster]
  # change this to the name of one of the keypair sections defined above
  KEYNAME = starcluster_1
  # number of ec2 instances to launch
  CLUSTER_SIZE = 2
  # create the following user on the cluster
  CLUSTER_USER = sgeadmin
  # optionally specify shell (defaults to bash)
  CLUSTER_SHELL = bash
  # AMI for cluster nodes.
  NODE_IMAGE_ID = ami-af11d5c6
  # instance type for all cluster nodes
  NODE_INSTANCE_TYPE = cc1.4xlarge
  # list of volumes to attach to the master node (OPTIONAL)
  # these volumes, if any, will be NFS shared to the worker nodes
  VOLUMES = computehome

  [volume computehome]
  VOLUME_ID = vol-e9a69582
  MOUNT_PATH = /home

When launching the cluster, an error message is printed:

  ...
>>> Setting up the cluster...
>>> Attaching volume vol-e9a69582 to master node on /dev/sdz ...
>>> Configuring hostnames...
  2/2 ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
100%
  *** WARNING - Cannot find device /dev/sdz for volume {'device':
'/dev/sdz', '__name__': 'volume computehome', 'partition': None,
'mount_path': '/home', 'volume_id': 'vol-e9a69582'}
  *** WARNING - Not mounting vol-e9a69582 on /home
  *** WARNING - This usually means there was a problemattaching the
EBS volume to the master node
>>> Creating cluster user: sgeadmin (uid: 1001, gid: 1001)
  2/2 |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| 100%
  ...

And indeed the volume appears to not be on /dev/sdz but on /dev/xvdz:
  root_at_master:~# fdisk -l

  Disk /dev/sda: 8589 MB, 8589934592 bytes
  255 heads, 63 sectors/track, 1044 cylinders
  Units = cylinders of 16065 * 512 = 8225280 bytes
  Sector size (logical/physical): 512 bytes / 512 bytes
  I/O size (minimum/optimal): 512 bytes / 512 bytes
  Disk identifier: 0x00000000

     Device Boot Start End Blocks Id System
  /dev/sda1 * 2 1044 8377897+ 83 Linux

  Disk /dev/xvdz: 21.5 GB, 21474836480 bytes
  255 heads, 63 sectors/track, 2610 cylinders
  Units = cylinders of 16065 * 512 = 8225280 bytes
  Sector size (logical/physical): 512 bytes / 512 bytes
  I/O size (minimum/optimal): 512 bytes / 512 bytes
  Disk identifier: 0x00000000

      Device Boot Start End Blocks Id System
  /dev/xvdz1 1 2610 20964793+ 83 Linux

But when I check on AWS management console it says the volume is
attached to /dev/sdz.

What am I doing wrong ?

Regards,

  Seb
Received on Thu Jul 14 2011 - 12:28:37 EDT