Method for dynamically resizing file systems

Abstract

Methods ( 100 ), systems ( 300 ) and computer program products are disclosed for uninterrupted execution of an application program ( 110 ). The method ( 100 ) comprises: receiving a write operation call to a native file system from an application program ( 110 ) being executed on an operating system; and dynamically allocating ( 120, 122 ) free data blocks to the native file system from at least one other file system in a group of file systems until completion of execution of the application program ( 110 ) thereby completing the write operation call. The group of file systems is configured to allow sharing of free data blocks amongst the group of file systems.

1 . A method for uninterrupted execution of an application program, the method comprising:
 receiving a write operation call to a native file system from an application program being executed on an operating system; and   dynamically allocating free data blocks to said native file system from at least one other file system in a group of file systems until completion of execution of the application program thereby completing the write operation call, wherein the group of file systems is configured to allow sharing of free data blocks amongst the group of file systems.   
     
     
         2 . The method as claimed in  claim 1 , further comprising selecting a set of file systems as the group of file system. 
     
     
         3 . The method as claimed in  claim 2 , further comprising determining if the application program requires additional data blocks for continued execution. 
     
     
         4 . The method as claimed in  claim 1 , further comprising performing the write operation call to the native file system. 
     
     
         5 . The method as claimed in  claim 1 , further comprising providing a virtual file system (VFS) layer of the operating system as an interface for one or more application programs. 
     
     
         6 . The method as claimed in  claim 1 , further comprising borrowing free data blocks from at least one other file system in the group of file systems thereby increasing the size of said native file system. 
     
     
         7 . The method as claimed in  claim 6  further comprising reducing the size of the other file system from which the free data blocks are borrowed. 
     
     
         8 . The method according to  claim 1 , further comprising configuring each file system in the group of file systems to limit the data blocks borrowed from each file system. 
     
     
         9 . The method according to  claim 1 , wherein the native file system is configured to borrow data blocks available from another file system within the group of file system thereby satisfying at least the requirements of completing the write operation call for the executing application program. 
     
     
         10 . The method according to  claim 1 , comprising reducing the size of the native file system by releasing the borrowed data blocks in response to reduced usage of the native file system and increasing the size of the other file system in the group of file systems that yielded the borrowed data blocks, thereby resorting normalcy to the file system. 
     
     
         11 . The method according to  claim 1 , wherein disk space utilized across the group of file systems is constant. 
     
     
         12 . The method according to  claim 1 , comprising checking if the native file system belongs to the group of file systems. 
     
     
         13 . The method according to  claim 12 , further comprising verifying the borrow status of the file system in the group of file systems. 
     
     
         14 . The method according to  claim 13 , comprising:
 checking if the data blocks borrowed from the other file systems in the group of file system is less than the maximum limit of data blocks that can be borrowed; and   examining other free space details of the remaining file systems in the group of file system to determine if there is a file system to borrow from.   
     
     
         15 . The method according to  claim 14 , further comprising selecting the other file system, wherein the other file system comprises additional free data blocks more than required by the file system borrowing the data blocks. 
     
     
         16 . The method according to  claim 1 , wherein the step of dynamically allocating further comprises:
 reducing a size of storage space of the other file system in response to a file system specific call on the other file system;   reducing a size of a logical volume of the other file system to match the reduced size of the other file system using a logical volume specific function called on a volume group;   increasing the logical volume size of said native file system borrowing said free data blocks to utilize the free disk space freed by the logical volume of said other file system; and   updating the status of both said native and other file systems.