System and method for providing write-once-read-many (WORM) storage
Techniques for providing write-once-read-many (WORM) storage are described herein. According to one embodiment, a range of values is received to set an attribute of a file, where the received range of values is outside of an ordinary range of the attribute in accordance with a file system associated with the file. In addition, a management action is received to be associated with the received range of values of the attribute, where the management action is unrelated to an ordinary action associated with the attribute of the file in accordance with the file system. In response, the received management action is associated with the received range of values of the attribute. Other methods and apparatuses are also described.
1. A computer-implemented method for managing files, comprising:
associating a range of values with a time attribute of a file, wherein the range of values is outside of an ordinary range of the time attribute in accordance with a file system associated with the file, wherein the time attribute is a standard file attribute of the file system;
associating a management action with the range of values of the time attribute, wherein the management action includes an action that is unrelated to an ordinary action associated with the time attribute of the file in accordance with the file system, where in the ordinary action includes setting a time value of the time attribute;
in response to a request subsequently received from a client via a standard call of the file system to set the time attribute of the file to a predetermined value, determining whether the predetermined value is within the range of values and is outside of the ordinary range of the time attribute of the file; and
performing the management action if the predetermined value is within the range of values and is outside of the ordinary range of the attribute of the file, including designating the file as a write-once-read-many (WORM) file, and setting a WORM retention period of the WORM file based on the predetermined value,
wherein the designating the file and setting the WORM retention period are performed in response to the request as a single request from the client.
2. The method of claim 1 , wherein the time attribute of the file is defined in a standard metadata data structure associated with the file.
3. The method of claim 2 , further comprising performing the ordinary action associated with the time attribute of the file if the predetermined value is within the ordinary range of the time attribute in accordance with a file system associated with the file.
4. The method of claim 2 , wherein the time attribute of the file is not modified if the predetermined value is within the range of values.
5. The method of claim 2 , further comprising performing the ordinary action associated with the time attribute of the file in addition to the management action.
6. The method of claim 2 , wherein the range of values includes a minimum time and a maximum time.
7. The method of claim 6 , further comprising setting a separate attribute associated with the file to indicate that the file is a WORM file without modifying the time time attribute of the file.
8. The method of claim 6 , wherein the time attribute of the file is one of an access time (atime) attribute, a status change time (ctime) attribute, and a modified time (mtime) attribute compatible with the file system associated with the file.
9. The method of claim 6 , wherein determining whether the predetermined value is within the range of values and is outside of the ordinary range of the time attribute of the file comprises
determining whether the predetermined value is greater than a current time plus the minimum time and less than the current time plus the maximum time,
wherein the file is designated as the WORM file and the WORM retention period for the file is set based on the predetermined value if the predetermined value is greater than the current time plus the minimum time and less than the current time plus the maximum time.
10. The method of claim 9 , wherein setting the WORM retention period comprises storing the predetermined value as a WORM retention date in a separate attribute for the file.
11. The method of claim 9 , further comprising:
in response to a request for modifying the file, determining whether the file is designated as a WORM file; and
rejecting the request if the file is designated as a WORM file.
12. The method of claim 11 , wherein determining whether the file is designated as a WORM file comprises:
determining a WORM retention date of the file based on the WORM retention period, and
comparing the current time with the WORM retention date of the file, wherein the file is a WORM file if the current time is less than the WORM retention date of the file.
13. The method of claim 9 , further comprising:
in response to a second request to set the time attribute of the file to a second predetermined value, determining a WORM retention date of the file based on the WORM retention period, determining whether the second predetermined value is greater than the WORM retention date of the file and less than the current time plus the maximum time; and
updating the WORM retention date to the second predetermined value if the second predetermined value is greater than the WORM retention date of the file and less than the current time plus the maximum time.
14. A system for managing files, comprising:
a processor; and
a memory for storing instructions, which when executed from the memory, cause the processor to
associate a range of values with a time attribute of a file, wherein the range of values is outside of an ordinary range of the time attribute in accordance with a file system associated with the file, wherein the time attribute of the file is a standard file attribute of the file system,
associate a management action with the range of values of the time attribute, wherein the management action includes an action that is unrelated to an ordinary action associated with the time attribute of the file in accordance with the file system, where in the ordinary action includes setting a time value of the time attribute;
in response to a request subsequently received from a client via a standard call of the file system to set the time attribute of the file to a predetermined value, determine whether the predetermined value is within the range of values and is outside of the ordinary range of the time attribute of the file, and
perform the management action if the predetermined value is within the range of values and outside of the ordinary range of the time attribute of the file, including designating the file as a write-once-read-many (WORM) file, and
setting a WORM retention period of the WORM file based on the predetermined value,
wherein the designating the file and setting the WORM retention period are performed in response to the request as a single request from the client.
15. A machine-readable storage medium having instructions stored therein, which when executed by a processor, cause the processor to perform a method for managing files, the method comprising:
associating a range of values with a time attribute of a file, wherein the range of values is outside of an ordinary range of the time attribute in accordance with a file system associated with the file, wherein the time attribute of the file is a standard file attribute of the file system,
associating a management action with the range of values of the time attribute, wherein the management action includes an action that is unrelated to an ordinary action associated with the time attribute of the file in accordance with the file system,
in response to a request subsequently received from a client via a standard call of the file system to set the time attribute of the file to a predetermined value, determining whether the predetermined value is within the range of values and is outside of the ordinary range of the time attribute of the file, and
performing the management action if the predetermined value is within the range of values and outside of the ordinary range of the time attribute of the file, including designating the file as a write-once-read-many (WORM) file, and setting a WORM retention period of the WORM file based on the predetermined value,
wherein the designating the file and setting the WORM retention period are performed in response to the request as a single request from the client.
16. A machine-readable storage medium having instructions stored therein, which when executed by a processor, cause the processor to perform a method for managing files, the method comprising:
associating a range of values with a time attribute of a file, wherein the range of values is outside of an ordinary range of the time attribute in accordance with a file system associated with the file, wherein the time attribute of the file is a standard file attribute of the file system,
associating a management action with the range of values of the time attribute, wherein the management action includes an action that is unrelated to an ordinary action associated with the time attribute of the file in accordance with the file system, where in the ordinary action includes setting a time value of the time attribute;
in response to a request subsequently received from a client via a standard call of the file system to set the time attribute of the file to a predetermined value, determining whether the predetermined value is within the range of values and is outside of the ordinary range of the time attribute of the file, and
performing the management action if the predetermined value is within the range of values and outside of the ordinary range of the time attribute of the file, including designating the file as a write-once-read-many (WORM) file, and setting a WORM retention period of the WORM file based on the predetermined value,
wherein the designating the file and setting the WORM retention period are performed in response to the request as a single request from the client.
17. The method of claim 16 , further comprising:
storing the first predetermined value as a WORM retention date in a separate attribute of the file if the first predetermined value is greater than the current time plus the minimum WORM retention time and less than the current time plus the maximum WORM retention time.
18. The method of claim 17 , further comprising:
in response to a second request to set the time attribute of the file to a second predetermined value, determining the WORM retention date of the file based on the WORM retention period, determining whether the second predetermined value is greater than the WORM retention date and less than the current time plus the maximum WORM retention time; and
updating the WORM retention date to the second predetermined value if the second predetermined value is greater than the WORM retention date and less than the current time plus the maximum WORM retention time.