device-eth0-does-not-seem-to-be-present,delaying initialization

Error:  "device-eth0-does-not-seem-to-be-present"



Cause
when I cloned one of my Linux virtual machine. So the cloned machine was not able to detect the NIC and every time I tried to restart the network it was throwing this error


Solution

The MAC id details for the NIC card is stored in the below mentioned file which is automatically created every time the machine boots.

                     /etc/udev/rules.d/70-persistent-net.rules

If you open this file the contents would be like this


Delete this file

           rm -f /etc/udev/rules.d/70-persistent-net.rules

Reboot the machine i.e  init 6

Now we can see difference in MAC id and NIC card name


Copy the new MAC id and NIC card name to your ifcfg-eth0 file

vi /etc/sysconfig/network-scripts/ifcfg-eth0



Restart the Network service using :  service network restart

check for IP details using " ifconfig"


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  • OpenStack Swift, also known as OpenStack Object Storage, is an open source object storage system that is licensed under the Apache 2.0 license and runs on standard server hardware.
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 Swift Components:
 =================

 1.Proxy Server
Tie together the Swift architecture
Request routing
Exposes the public API

 2.Ring
Maps names to entities (accounts, containers, objects) on disk.
Stores data based on zones, devices, partitions, and replicas
Weights can be used to balance the distribution of partitions
Used by the Proxy Server for many background processes
 3.Object Server
Blob storage server
metadata kept in xattrs
data in binary format
Object location based on name & timestamp hash

Swift & Large Object Storage:
==============================

Default 5GB limit on the size of an uploaded object
Segmentation makes download size of a single object is virtually unlimited
Segments large object are uploaded and a special manifest file is created when downloaded, all segments are concatenated as a single object.
Greater upload speed
Possible parallel uploads of segments.

Swift Components:
=================

Replication
       Keep the system consistent, handle failures

Updaters
       Process failed or queued updates

Auditors
      Verify integrity of objects, containers, and accounts

Container Server:
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Account Server:
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Limitation:
===========
Search is limited to queries based on the object's name and to a single bucket. No metadata or content-based search capabilities are provided.