Methods and apparatus for storing updatable user data using a cluster of application servers

A method for storing updatable user data using a cluster of application servers, at least one of which is a point-in-time (PTC) managing server that does not store updatable user data and at least a plurality of which are non-managing application servers that do store updatable user data, said method comprising:

• maintaining, in the PTC managing server, a local copy of metadata pertaining to user data stored in said non-managing application servers of said cluster in a memory local to said PTC managing server,
• storing updatable user data across a plurality of non-managing application servers in file systems of associated local storage devices;
• maintaining, in each non-managing application server, a local copy of metadata pertaining to user data stored in the file system of the associated local storage device;
• receiving a PTC request from a client;
• and
• creating a PTC of the metadata in the PTC managing server.

An apparatus for storing updatable user data and for providing client access to an application, said apparatus comprising:

• a plurality of application servers interconnected via a network, each said application server having an associated local storage device on which resides a local file system;
• and
• a router/switch configured to route requests received from clients to said application servers via said network;
• wherein each said application server is configured to manage the associated local storage device to store updatable user data and metadata pertaining thereto, and, in response to requests to do so:
• to freeze its local file system,
• to create a point-in-time copy of the metadata of its local file, and
• to unfreeze its local file system;
• and further wherein at least one said application server is configured to be responsive to a point-in-time (PTC) request from a client to signal, via said network, for each application server to freeze its local file system, to create a PTC of the metadata of its local file system, and to unfreeze its local file system.

An apparatus for storing updatable user data and for providing client access to an application, said apparatus comprising:

• a plurality of application servers interconnected via a network, each said application server having an associated local storage device on which resides a local file system;
• and
• a router/switch configured to route requests received from clients to said application servers via said network;
• wherein at least one said application server is a point-in-time copy (PTC) managing server and a plurality of remaining application servers are non-managing servers;
• and further wherein said PTC managing server is configured to retain a local copy of metadata pertaining to user data stored in said non-managing application servers of said cluster in a memory local to said PTC managing server;
• said apparatus is configured to store updatable user data across a plurality of said non-managing application servers in file systems of associated local storage devices;
• said non-managing application servers are configured to manage a local copy of metadata pertaining to user data stored on the file system of the associated local storage device;
• and
• said apparatus is further configured to receive a PTC request from a client and to create a PTC of the metadata in the PTC managing server.