Dynamic disk redistribution
View Patent ↗Methods and systems are disclosed to perform dynamic disk data redistribution in a database environment. The methods and systems disclosed herein provide for the transparent redistribution of data across multiple physical disks of a database while maintaining accessibility to the database. Methods and systems are also disclosed for handling requests to perform database operations on data that is in the process of being redistributed.
1. A method for performing a dynamic disk redistribution while maintaining a user's ability to access to a database, the method comprising:
initializing a temporary file;
copying a live database file from a memory device to the temporary file, wherein the temporary file comprises redistributed data;
swapping the live database file with the temporary file, wherein swapping the live database file with the temporary file comprises distributing data from the temporary file evenly over one or more physical disks that make up the database;
purging the live database file being copied; and
wherein the redirection method further includes:
receiving a next I/O operation during the dynamic disk redistribution;
determining if the next I/O operation relates to redistributed data:
upon determining that the next I/O operation does not relate to the redistributed data, performing the next I/O operation;
upon determining that the next I/O operation relates to the redistributed data:
determining if a target of the next I/O operation resides in the temporary file:
upon determining that the target does not reside in the temporary file, performing the next I/O operation on the live database file;
upon determining that the next I/O operation relates to the redistributed data, performing the next I/O operation on the temporary file and the live database file.
2. The method of claim 1 , wherein the temporary file has all of the physical attributes of the live database file.
3. The method of claim 1 , wherein the I/O operation comprises one of:
a write operation;
a create operation; and
a delete operation.
4. The method of claim 1 , further comprising temporarily suspending I/O operations when swapping the live database file with the temporary file.
5. A computer storage medium encoding computer executable instructions that, when executed by at least on processor, perform a method of dynamic disk redistribution, the method comprising: receiving a redistribute command; initializing a temporary file;
copying live database file to the temporary file, wherein the temporary file comprises redistributed data;
writing the temporary file to the database, wherein writing the temporary file comprises distributing data, from the temporary file evenly over one or more physical disks that make up a database;
purging the live database file being copied; and
wherein the redirection method further includes:
receiving a next I/O operation during the dynamic disk redistribution;
determining if the next I/O operation relates to redistributed data:
upon determining that the next I/O operation does not relate to the redistributed data, performing the next I/O operation;
upon determining that the next I/O operation relates to the redistributed data:
determining if a target of the next I/O operation resides in the temporary file:
upon determining that the target does not reside in the temporary file, performing the next I/O operation on the live database file;
upon determining that the next I/O operation relates to the redistributed data, performing the next I/O operation on the temporary file and the live database file.
6. The method of claim 5 , wherein the I/O operation comprises one of:
a write operation;
a create operation; and
a delete operation.
7. A system for performing a dynamic disk redistribution while maintaining a user's ability to access to a database, the system comprising:
at least one processing unit; and
memory storing computer executable instructions that, when executed by the at least one processing unit, perform a method of:
receiving a redistribute command;
initializing a temporary file;
copying live database file to the temporary file, wherein the temporary file comprises redistributed data;
receiving an I/O operation;
determining if a target of the I/O operation is located in the temporary file;
upon determining that the target of the I/O operation is located in the temporary file, performing the I/O operation on the temporary file and the live database file;
purging the live database file being copied; and
wherein the redirection method further includes:
receiving a next I/O operation during the dynamic disk redistribution;
determining if the next I/O operation relates to redistributed data:
upon determining that the next I/O operation does not relate to the redistributed data, performing the next I/O operation;
upon determining that the next I/O operation relates to the redistributed data:
determining if a target of the next I/O operation resides in the temporary file:
upon determining that the target does not reside in the temporary file, performing the next I/O operation on the live database file;
upon determining that the next I/O operation relates to the redistributed data, performing the next I/O operation on the temporary file and the live database file.
8. The system of claim 7 , wherein the I/O operation comprises one of: a write operation; a create operation; and a delete operation.
9. The system of claim 7 , wherein the redistributed data comprises a plurality of files.