Checkpoint recovery using a B-tree intent log with syncpoints
US8745005B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 2006 |
| Grant date | Jun 3, 2014 |
| Priority date | — |
| Expiry date | Sep 29, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/1471
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A networked data storage system includes a primary volume and a pointer-based virtual secondary volume. The secondary volume has B-tree checkpoints of the state of a primary filesystem of the primary volume. Intermediate syncpoints are declared between checkpoint checkpoints. The syncpoints are logical locations on the secondary volume where the B-tree is known to be in a consistent state. The frequency of syncpoints may be set by an administrator in units of blocks, i.e., a syncpoint to be taken every n blocks. Before performing a B-tree split, entire images of the leaves and parent node involved in the split are written to an intent log in a relatively fast transaction that may comprise a single I/O operation to contiguous memory. Movement of data between leaf nodes and changes to the parent nodes as a result of the split operation proceed asynchronously. In the event of a reboot before the split operation is complete, the intent log is used to complete the split transaction from the most recent syncpoint. When a new syncpoint is declared, the intent log and dirty leaves are flushed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.