Fast Data Initialization

• US 20150089138A1
• Filed: 07/21/2014
• Published: 03/26/2015
• Est. Priority Date: 09/20/2013
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Tao, Zuoyu, Shi, Jia, Umamageswaran, Kothanda, Aya, Selcuk
• Granted Patent: US 9,430,383 B2
• Time in Patent Office: Days
• US Class Current: 711/119
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 12/0804 with main memory updating G06F12/0806 takes precedence
• CPC Class Codes: G06F 12/0806 Multiuser, multiprocessor or multiprocessing cache systems
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache
• CPC Class Codes: G06F 12/0893 Caches characterised by their organisation or structure
• CPC Class Codes: G06F 16/16 File or folder operations, e.g. details of user interfaces specifically adapted to file systems
• CPC Class Codes: G06F 2212/1008 Correctness of operation, e.g. memory ordering
• CPC Class Codes: G06F 2212/1024 Latency reduction
• CPC Class Codes: G06F 2212/225 Hybrid cache memory, e.g. having both volatile and non-volatile portions
• CPC Class Codes: G06F 2212/46 Caching storage objects of specific type in disk cache
• CPC Class Codes: G06F 2212/604 Details relating to cache allocation
• CPC Class Codes: G06F 2212/608 Details relating to cache mapping
• CPC Class Codes: G06F 2212/7207 management of metadata or control data
• CPC Class Codes: G06F 2212/7208 Multiple device management, e.g. distributing data over multiple flash devices
• CPC Class Codes: G06F 3/06 Digital input from, or digital output to, record carriers , e.g. RAID, emulated record carriers or networked record carriers
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0611 in relation to response time
• CPC Class Codes: G06F 3/0631 by allocating resources to storage systems
• CPC Class Codes: G06F 3/0632 by initialisation or re-initialisation of storage systems
• CPC Class Codes: G06F 3/0643 Management of files
• CPC Class Codes: G06F 3/0685 : Hybrid storage combining heterogeneous device types, e.g. hierarchical storage, hybrid arrays
• CPC Class Codes: G06F 3/0689 : Disk arrays, e.g. RAID, JBOD

Abstract

A method and system for fast file initialization is provided. An initialization request to create or extend a file is received. The initialization request comprises or identifies file template metadata. A set of allocation units are allocated, the set of allocation units comprising at least one allocation unit for the file on a primary storage medium without initializing at least a portion of the file on the primary storage medium. The file template metadata is stored in a cache. The cache resides in at least one of volatile memory and persistent flash storage. A second request is received corresponding to a particular allocation unit of the set of allocation units. Particular file template metadata associated with the particular allocation unit is obtained. In response to the second request, at least a portion of a new allocation unit is generated.

Claims

1. A method comprising:

receiving an initialization request to create or extend a file, wherein the initialization request comprises or identifies file template metadata;

allocating a set of allocation units comprising at least one allocation unit for the file on a primary storage medium without initializing at least a portion of the file on the primary storage medium;

storing the file template metadata in at least one of a volatile memory cache and a persistent memory cache;

receiving a second request corresponding to a particular allocation unit of the set of allocation units;

obtaining particular file template metadata associated with the particular allocation unit; and

in response to the second request, generating at least a portion of the particular allocation unit;

wherein the method is performed by one or more computing devices.

2. The method of claim 1, wherein generating at least a portion of the particular allocation unit comprises generating at least a portion of a pre-write allocation unit based at least in part on the file template metadata.

3. The method of claim 1,

wherein the second request is a write request to the particular allocation unit;

and

wherein generating at least a portion of the particular allocation unit is based at least in part on the write request.

4. The method of claim 3,

wherein generating at least a portion of the particular allocation unit comprises generating at least one block of the particular allocation unit and updating tracking data corresponding to blocks of the particular allocation unit.

5. The method of claim 1, further comprising:

caching a plurality of write requests to a selected allocation unit of the set of allocation units; and

generating the selected allocation unit based at least in part on the cached plurality of write requests.

6. The method of claim 1, further comprising:

storing the at least one new allocation unit in persistent cache storage associated with the primary storage medium.

7. The method of claim 6, further comprising:

receiving a third request corresponding to a block of a second allocation unit;

determining, based on tracking data for the second allocation unit, whether the block is stored in the persistent cache storage;

when the block is stored in the persistent cache storage, accessing the block in flash memory;

when the block is not stored in the persistent cache storage, generating the block based at least in part on the file template metadata corresponding to the second allocation unit.

8. The method of claim 6, further comprising:

writing a particular allocation unit stored in the persistent cache storage to a corresponding allocation unit on the primary storage medium;

terminate storing the particular allocation unit from the persistent cache storage.

9. The method of claim 1, further comprising:

storing, in volatile memory, a mapping from the at least one allocation unit to the file template metadata.

18. The non-transitory computer-readable medium of claim 1, the instructions which, when executed by the one or more processors, further cause the one or more processors to:

store, in volatile memory, a mapping from the at least one new allocation unit to the file template metadata.

10. A non-transitory computer-readable medium storing instructions which, when executed by one or more processors, cause the one or more processors to:

receive an initialization request to create or extend a file, wherein the initialization request comprises or identifies file template metadata;

allocate a set of allocation units comprising at least one allocation unit for the file on a primary storage medium without initializing at least a portion of the file on the primary storage medium;

store the file template metadata in at least one of a volatile memory cache and a persistent memory cache;

receive a second request corresponding to a particular allocation unit of the set of allocation units;

obtain particular file template metadata associated with the particular allocation unit; and

in response to the second request, generating at least a portion of the particular allocation unit.

11. The non-transitory computer-readable medium of claim 10, wherein generating at least a portion of the particular allocation unit comprises generating at least a portion of a pre-write allocation unit based at least in part on the file template metadata.

12. The non-transitory computer-readable medium of claim 10,

wherein the second request is a write request to the particular allocation unit;

and

wherein generating at least a portion of the particular allocation unit is based at least in part on the write request.

13. The non-transitory computer-readable medium of claim 12,

wherein generating at least a portion of the particular allocation unit comprises generating at least one block of the particular allocation unit and updating tracking data corresponding to blocks of the particular allocation unit.

14. The non-transitory computer-readable medium of claim 10, the instructions which, when executed by the one or more processors, further cause the one or more processors to:

cache a plurality of write requests to a selected allocation unit of the set of allocation units; and

generate the selected allocation unit based at least in part on the cached plurality of write requests.

15. The non-transitory computer-readable medium of claim 10, the instructions which, when executed by the one or more processors, further cause the one or more processors to:

store the at least one new allocation unit in persistent cache storage associated with the primary storage medium.

16. The non-transitory computer-readable medium of claim 15, the instructions which, when executed by the one or more processors, further cause the one or more processors to:

receive a third request corresponding to a block of a second allocation unit;

determine, based on tracking data for the second allocation unit, whether the block is stored in the persistent cache storage;

when the block is stored in the persistent cache storage, access the block in flash memory;

when the block is not stored in persistent cache storage, generate the block based at least in part on the file template metadata corresponding to the one second allocation unit.

17. The non-transitory computer-readable medium of claim 15, the instructions which, when executed by the one or more processors, further cause the one or more processors to:

write a particular allocation unit stored in the persistent cache storage to a corresponding allocation unit on the primary storage medium;

terminate storing the particular allocation unit from the persistent cache storage.

19. A system comprising:

a plurality of primary storage devices comprising a plurality of allocation units;

a plurality of persistent cache devices;

volatile memory;

one or more processors configured to;

receive an initialization request to create or extend a file, wherein the initialization request is associated with file template metadata;

allocate a set of allocation units of the plurality of allocation units for the file without initializing the file on the primary storage medium;

store the file template metadata in the volatile memory;

receive a read request corresponding a first allocation unit of the set of allocation units;

in response to the read request, generate at least one block of the particular allocation unit based on the file template metadata.

20. The system of claim 19, wherein the one or more processors are further configured to:

receive a write request corresponding to a second block of a second allocation unit;

store the second block of the second allocation unit in a persistent cache device corresponding to a primary storage device that contains the second allocation unit.