Providing a reliable operating system for clients of a net-booted environment

A network computer (NC) client comprising:

• a bootstrapping means for booting from a boot image provided by an NC server, the boot image including information identifying the location of one or more user system volumes on the NC server, and locally executing the boot image and mounting the one or more system volumes, the one or more user system volumes containing operating system software;
• and
• a redirecting means, responsive to an attempt to modify the contents of the one or more user system volumes, for causing information identifying a modification associated with the attempt to be recorded on the NC server separate from the one or more user system volumes in a shadow system volume associated with the NC client;
• wherein
• the one or more system volumes are presented as a split operating system including a core operating system volume that can be read but not written by the NC client and the user operating system volume that can be read and/or written by the NC client, wherein the associated storage area comprises the shadow volume corresponding to the user operating system volume, and wherein causing information identifying a modification associated with the attempt to be recorded comprises tracking modifications to the user operating system volume in the shadow volume.

A method comprising:

• a network computer (NC) client booting from a boot image provided by an NC server, the boot image including information identifying the location of one or more user system volumes on the NC server, the NC client locally executing the boot image and mounting the one or more system volumes, the one or more user system volumes containing operating system software;
• and
• in response to a write request from a file system of the NC client that contains a modification to the one or more user system volumes, a block device driver of the NC client redirecting the write request and causing information identifying the modification to be recorded on the NC server in a shadow system volume associated with the NC client that is separate from the one or more user system volumes;
• wherein
• the one or more system volumes are presented to the NC client as a split operating system including a core operating system volume that can be read but not written by the NC client and the user operating system volume that can be read and/or written by the NC client, wherein the storage area associated with the NC client comprises the shadow volume corresponding to the user operating system volume, and wherein the NC client causing information identifying a modification associated with the attempt to be recorded comprises tracking modifications to the user operating system volume in the shadow volume.

A method comprising:

• a network computer (NC) client booting from a boot image provided by an NC server, the boot image including information identifying the location of one or more user system volumes on the NC server, the NC client locally executing the boot image and mounting the one or more system volumes, the one or more user system volumes containing operating system software that has one or more customizable attributes;
• and
• in response to a change to an attribute of the one or more customizable attributes, the NC client causing information identifying the change to be recorded on the NC server in a shadow system volume associated with the NC client that is separate and distinct from the one or more user system volumes;
• wherein
• the one or more system volumes are presented to the NC client as a split operating system including a core operating system volume that can be read but not written by the NC client and the user operating system volume that can be read and/or written by the NC client, wherein the storage area associated with the NC client comprises the shadow volume corresponding to the user operating system volume, and wherein the NC client causing information identifying a modification associated with the attempt to be recorded comprises tracking modifications to the user system volume in the shadow volume.

A method comprising:

• a network computer (NC) server providing a boot image to an NC client, the boot image including information identifying the location of one or more user system volumes on the NC server, the NC client locally executing the boot image and mounting the one or more system volumes, the one or more user system volumes containing operating system software;
• presenting to the NC client, the one or more system volumes as a split operating system including a core operating system volume that can be read but not written by the NC client and the user operating system volume that can be read and/or written by the NC client, wherein the storage area associated with the NC client comprises the shadow volume corresponding to the user operating system volume, and wherein the NC client causing information identifying a modification associated with the attempt to be recorded comprises tracking modifications to the user operating system volume in the shadow volume;
• and
• in response to a write request from the NC client that contains a modification to the operating system software, the NC server recording information identifying the modification on the NC server in a shadow system volume associated with the NC client that is separate from the one or more user system volumes.

A network computer (NC) server comprising:

• a boot server means for providing a boot image to an NC client, the boot image including information identifying the location of one or more user system volumes on the NC server, so that the NC client can locally execute the boot image and mount the one or more system volumes, the one or more user system volumes containing operating system software;
• a presentation means for presenting to the NC client, the one or more system volumes as a split operating system including a core operating system volume that can be read but not written by the NC client and the user operating system volume that can be read and/or written by the NC client, wherein the storage area associated with the NC client comprises the shadow volume corresponding to the user operating system volume, and wherein the NC client causing information identifying a modification associated with the attempt to be recorded comprises tracking modifications to the user operating system volume in the shadow volume;
• and
• a storage management means for recording information identifying a modification to the operating system software in a shadow system volume associated with the NC client that is separate from the one or more user system volumes, the storage management means operative in response to a write request from the NC client that contains the modification.

A machine-readable medium having stored thereon data representing sequences of instructions, the sequences of instructions which, when executed by a processor, cause the processor to perform the steps comprising:

• providing a boot image to an NC client, the boot image including information identifying the location of one or more user system volumes on the NC server and set so that the NC client may locally execute the boot image and mount the one or more system volumes, the one or more user system volumes containing operating system software;
• presenting to the NC client, the one or more system volumes as a split operating system including a core operating system volume that can be read but not written by the NC client and the user operating system volume that can be read and/or written by the NC client, wherein the storage area associated with the NC client comprises the shadow volume corresponding to the user operating system volume, and wherein the NC client causing information identifying a modification associated with the attempt to be recorded comprises tracking modifications to the user operating system volume in the shadow volume;
• and
• in response to a write request from the NC client that contains a modification to the operating system software, the NC server recording information identifying the modification on the NC server in a shadow system volume associated with the NC client that is separate from the one or more user system volumes.