Hi,

I have 4 instances running OK, but when I want to run the 5th, I get the error showed below.

If I run euca-describe-availability-zones verbose I get this (so, I have more resources to use):

AVAILABILITYZONE FUSEIM 192.168.4.135
AVAILABILITYZONE |- vm types free / max cpu ram disk
AVAILABILITYZONE |- m1.small 0008 / 0016 1 128 2
AVAILABILITYZONE |- c1.medium 0008 / 0016 1 256 5
AVAILABILITYZONE |- m1.large 0004 / 0008 2 512 10
AVAILABILITYZONE |- m1.xlarge 0004 / 0008 2 1024 20
AVAILABILITYZONE |- c1.xlarge 0002 / 0004 4 2048 20

I'm 3 machines (1 cc and 2 nc). My conf file is:

#
# Eucalyptus configuration.
# This variable points to where eucalyptus has been installed.
EUCALYPTUS="/"
# This is the username that you would like eucalyptus to run as
EUCA_USER="eucalyptus"
DISABLE_ISCSI="N"
DISABLE_DNS="Y"
ENABLE_WS_SECURITY="Y"
CLOUD_OPTS=""
LOGLEVEL="DEBUG"

####
# These following are Cluster Controller configuration options.
####
# This is the port the Cluster Controller will be listening on.
CC_PORT="8774"

# This option configures the Cluster Controller's scheduling policy.
# Currently, this option can be set to GREEDY (first node that is
# found that can run the VM will be chosen), ROUNDROBIN (nodes are
# selected one after another until one is found that can run the VM),
# or POWERSAVE (nodes are put to sleep when they are not running VMs,
# and reawakened when new resources are required. VMs will be placed
# on the first awake machine, followed by machines that are asleep).
SCHEDPOLICY="ROUNDROBIN"

# Powersave options. POWER_IDLETHRESH is the number of seconds that a
# node can remain idle (i.e. no running VMs) before a powerdown is
# attempted. POWER_WAKETHRESH is the number of seconds that
# Eucalyptus should wait after attempting a node wake-up before it
# will consider the node actually down (and not waking up).
POWER_IDLETHRESH="300"
POWER_WAKETHRESH="300"

# The list of Node Controllers the Cluster Controller will communicate with.
#
# If you are running Rocks, you can run "rocks list host" to
# find out the list of machines available to you (in our case we are
# interested in the VM Container kind).
NODES=" 192.168.4.136 192.168.4.137"

# The name of the Node Controller service. Change this if you want
# to plug in your own Node Controller service.
NC_SERVICE="axis2/services/EucalyptusNC"

####
# The following are Node Controller configuration options.
####
NC_PORT="8775"
HYPERVISOR="xen"
USE_VIRTIO_DISK="0"
USE_VIRTIO_ROOT="0"
USE_VIRTIO_NET="0"
MAX_CORES="8"

####
# The following are options for image storage on the Node Controller
####
INSTANCE_PATH="/usr/local/eucalyptus/"

####
# The following are networking options
####
VNET_PUBINTERFACE="eth0"
VNET_PRIVINTERFACE="eth0"
VNET_DHCPDAEMON="/usr/sbin/dhcpd"
VNET_MODE="SYSTEM"

I have enough disk space and enough resources. Even though I can run up to 4 instances.

Please help me.

The running instances are:
RESERVATION r-502F08C9 liriarte default
INSTANCE i-386E0699 emi-5C6E2760 192.168.4.104 192.168.4.104 running liriarte 0 m1.xlarge 2012-01-10T18:00:59.956Z FUSEIM eki-8DB416EF eri-880616CE
RESERVATION r-44B307D3 liriarte default
INSTANCE i-473807EE emi-5C6E2760 192.168.4.112 192.168.4.112 running liriarte 0 m1.xlarge 2012-01-03T12:14:30.914Z FUSEIM eki-8DB416EF eri-880616CE
RESERVATION r-41BE0868 liriarte default
INSTANCE i-3BB00757 emi-5C6E2760 192.168.4.165 192.168.4.165 running liriarte 0 m1.xlarge 2012-01-03T12:05:27.572Z FUSEIM eki-8DB416EF eri-880616CE
RESERVATION r-48A209CC liriarte default
INSTANCE i-362B079F emi-5C6E2760 192.168.4.114 192.168.4.114 running liriarte 0 m1.xlarge 2012-01-03T18:38:40.785Z FUSEIM eki-8DB416EF eri-880616CE

ERROR:
[Tue Jan 17 12:51:05 2012][004231][EUCAERROR ] libvirt: POST operation failed: xend_post: error from xen daemon: (xend.err 'Device 2049 (vbd) could not be connected. /etc/xen/scripts/block failed; error detected.') (code=11)
[Tue Jan 17 12:51:05 2012][004231][EUCADEBUG ] doDescribeResource() invoked
[Tue Jan 17 12:51:06 2012][004231][EUCADEBUG ] doDescribeInstances() invoked
[Tue Jan 17 12:51:06 2012][004231][EUCADEBUG ] doDescribeInstances(): instanceId=i-3BB00757 publicIp=192.168.4.165 privateIp=192.168.4.165 mac=d0:0d:3B:B0:07:57 vlan=-1 networkIndex=-1
[Tue Jan 17 12:51:06 2012][004231][EUCADEBUG ] doDescribeInstances(): instanceId=i-473807EE publicIp=192.168.4.112 privateIp=192.168.4.112 mac=d0:0d:47:38:07:EE vlan=-1 networkIndex=-1
[Tue Jan 17 12:51:06 2012][004231][EUCADEBUG ] doDescribeInstances(): instanceId=i-348A06AE publicIp=0.0.0.0 privateIp=0.0.0.0 mac=d0:0d:34:8A:06:AE vlan=-1 networkIndex=-1
[Tue Jan 17 12:51:06 2012][004231][EUCAERROR ] libvirt: POST operation failed: xend_post: error from xen daemon: (xend.err 'Device 2049 (vbd) could not be connected. /etc/xen/scripts/block failed; error detected.') (code=11)
[Tue Jan 17 12:51:08 2012][004231][EUCAERROR ] libvirt: POST operation failed: xend_post: error from xen daemon: (xend.err 'Device 2049 (vbd) could not be connected. /etc/xen/scripts/block failed; error detected.') (code=11)
[Tue Jan 17 12:51:09 2012][004231][EUCAERROR ] libvirt: POST operation failed: xend_post: error from xen daemon: (xend.err 'Device 2051 (vbd) could not be connected. /etc/xen/scripts/block failed; error detected.') (code=11)
[Tue Jan 17 12:51:10 2012][004231][EUCAERROR ] libvirt: POST operation failed: xend_post: error from xen daemon: (xend.err 'Device 2051 (vbd) could not be connected. /etc/xen/scripts/block failed; error detected.') (code=11)
[Tue Jan 17 12:51:10 2012][004231][EUCAFATAL ] hypervisor failed to start domain
[Tue Jan 17 12:51:10 2012][004231][EUCADEBUG ] state change for instance i-348A06AE: Staging -> Shutoff (Extant)
[Tue Jan 17 12:51:10 2012][004231][EUCAERROR ] libvirt: Domain not found: xenUnifiedDomainLookupByName (code=42)
[Tue Jan 17 12:51:10 2012][004231][EUCAINFO ] cleaning up state for instance i-348A06AE