Linux : rsync

DRYRUN="--dry-run"
#DRYRUN=""

/usr/bin/rsync -v -e ssh $DRYRUN -a -H --exclude archive --exclude "lost+found" --exclude config --exclude log --rsync-path=/usr/bin/rsync --delete /source_DIR DESTINATION_SERVER:/DEST_DIR

OVM : MTU downgrade problem

https://oss.oracle.com/pipermail/oraclevm-errata/2015-February/000275.html

[4.3.0-55.el6.1] - Before connecting the emulated network interface (vif.x.y-emu) to a bridge, change the emu MTU to equal the MTU of the bridge to prevent the bridge from downgrading its own MTU to equal the emu MTU.

R : install ggplot2 package on Windows 8

Install Rtools for Windows : https://cran.r-project.org/bin/windows/Rtools/

Without RTools, we cannot compile the package.

In the R console , run :

install.packages("ggplot2", type="source",dependencies = TRUE)

R : stringsAsFactors

https://www.zoology.ubc.ca/~schluter/R/data/

stringsAsFactors = FALSE tells R to keep character variables as they are rather than convert to factors

OpenStack : Nova Error : NoValidHost

Problem:

On Controller node , File /var/log/nova/nova-conductor.log

2015-10-23 18:20:30.836 1572 ERROR nova.scheduler.utils [req-20b92c63-df02-4c16-941e-5b7c0b68aa96 b476579221d74f1eb0474fb5d970dead eec1d66ee98a46458c98f2c84607c229 - - -] [instance: d39eb1ab-14f8-4bc7-8029-3c5fb92cdf95] Error from last host: fedora-68 (node fedora-68): [u'Traceback (most recent call last):\n', u'  File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 2235, in _do_build_and_run_instance\n    filter_properties)\n', u'  File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 2381, in _build_and_run_instance\n    instance_uuid=instance.uuid, reason=six.text_type(e))\n', u"RescheduledException: Build of instance d39eb1ab-14f8-4bc7-8029-3c5fb92cdf95 was re-scheduled: Connection to glance host IP:9292 failed: Error finding address for http://IP:9292/v1/images/3f65b449-a945-4247-bcc2-e33d94a07cb6: ('Connection aborted.', error(113, 'EHOSTUNREACH'))\n"]
2015-10-23 18:20:32.368 1572 WARNING nova.scheduler.utils [req-20b92c63-df02-4c16-941e-5b7c0b68aa96 b476579221d74f1eb0474fb5d970dead eec1d66ee98a46458c98f2c84607c229 - - -] Failed to compute_task_build_instances: No valid host was found. There are not enough hosts available.
Traceback (most recent call last):

  File "/usr/lib/python2.7/site-packages/oslo_messaging/rpc/server.py", line 142, in inner
    return func(*args, **kwargs)

  File "/usr/lib/python2.7/site-packages/nova/scheduler/manager.py", line 86, in select_destinations
    filter_properties)

  File "/usr/lib/python2.7/site-packages/nova/scheduler/filter_scheduler.py", line 80, in select_destinations
    raise exception.NoValidHost(reason=reason)

NoValidHost: No valid host was found. There are not enough hosts available.

Solution : Check firewall for Controller node

Big Data : Spark

http://www.computing.co.uk/ctg/analysis/2432898/what-is-spark-six-reasons-why-cios-should-find-out-and-one-why-they-shouldnt

Oracle and VMware Support

VMware: http://www.vmware.com/support/policies/oracle-support.html


Oracle: https://support.oracle.com/epmos/faces/DocumentDisplay?id=249212.1

 Oracle has not certified any of its products on VMware virtualized environments. Oracle Support will assist customers running Oracle products on VMware in the following manner: Oracle will only provide support for issues that either are known to occur on the native OS, or can be demonstrated not to be as a result of running on VMware. If a problem is a known Oracle issue, Oracle support will recommend the appropriate solution on the native OS. If that solution does not work in the VMware virtualized environment, the customer will be referred to VMware for support. When the customer can demonstrate that the Oracle solution does not work when running on the native OS, Oracle will resume support, including logging a bug with Oracle Development for investigation if required. If the problem is determined not to be a known Oracle issue, we will refer the customer to VMware for support. When the customer can demonstrate that the issue occurs when running on the native OS, Oracle will resume support, including logging a bug with Oracle Development for investigation if required. NOTE: Oracle has not certified any of its products on VMware. For Oracle RAC, Oracle will only accept Service Requests as described in this note on Oracle RAC 11.2.0.2 and later releases.