| 摘要 |
A snapshot expansion system and a method, applicable to a logical volume manager, are provided. A snapshot space is allocated in a volume group space of a logical volume (LV) to create a snapshot. When a data write request is sent to the LV, the total capacity of the snapshot is compared with the current stored data volume of the snapshot space, thereby obtaining a difference representing the size of the remaining capacity of the snapshot space. Then, whether the difference is smaller than a preset value is detected. When the difference is smaller than the preset value, a capacity space is measured off in the volume group space to expand the capacity of the snapshot space through a standard expansion algorithm. The snapshot expansion system and method are capable of ensuring sufficient snapshot space to accommodate backup data, thereby ensuring availability of the snapshot.
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