The snapshot capability of the Qumulo file system preserves the state of a file system directory at a point in time.
An incremental scan operation uses the REST APIs provided by Qumulo for snapshot creation and change file tracking to optimize the scan time. To determine which files changed, a Change File Tracking operation is performed between the previous backup snapshot and the current backup snapshot.
In addition, the Qumulo scan and backup operations read data off the snapshots to shift load from the production data shares. To offload production data shares, two snapshots are created and retained, one for the current backup operation and the other for the previous backup operation.
Data Set for CIFS Shares and NFS Exports
File count: 100 million
File size: Mixed file size
The following table compares performance metrics between regular scans and Qumulo file system scans of CIFS share and NFS export snapshots, of new files and modified files.
CIFS
Backup type | Items | Regular scan time | Qumulo CFT scan time |
|---|---|---|---|
Full | Not applicable | 02:31:00 | 02:39:00 |
Incremental | 1 million, modified files | 00:58:00 | 00:30:00 |
Incremental | 1 million, new files under a new folder | 01:20:00 | 00:03:40 |
NFS
Backup type | Items | Regular scan time | Qumulo CFT scan time |
|---|---|---|---|
Full | Not applicable | 05:04:00 | 03:07:00 |
Incremental | 1 million, modified files | 07:02:00 | 00:37:00 |
Incremental | 1 million, new files under 1000 new folders | 07:13:00 | 00:15:00 |