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2.
Check the schedules you want to set. They can be set by monthly, weekly, daily, or hourly.
Check the
Auto Mapping
box to map a LUN automatically when the snapshot is taken.
And the LUN is allowed to access by the
Allowed Hosts
column.
3.
Click the
OK
to apply.
INFORMATION:
Daily snapshot will be taken at 00:00 daily.
Weekly snapshot will be taken every Sunday at 00:00.
Monthly snapshot will be taken every first day of the month at 00:00.
12.1.5.
Snapshot Notices
Snapshot function applies copy-on-write technique on volume and provides a quick and
efficient backup methodology. When taking a snapshot, it does not copy any data at first
time until a request of data modification comes in. The snapshot copies the original data to
snapshot space and then overwrites the original data with new changes. With this technique,
snapshot only copies the changed data instead of copying whole data. It will save a lot of
disk space.
Data Consistent Snapshot
Before using snapshot, users should understand why sometimes the data becomes
corrupted after rollback of snapshot. Please refer to the following diagram.
When the data is modified from the host computer, the data will pass through file system
and memory of the host (write cache). Then the host will flush the data from memory to
physical disks, no matter the disk is local disk (IDE or SATA), DAS (SCSI or SAS), or SAN
(fibre or iSCSI). From the viewpoint of the storage device, it cannot control the behavior of
the host side. It sometimes happens that when a snapshot is taken, some data is still in
memory and did not flush to disk. Then the snapshot may have an incomplete image of the
original data. The problem does not belong to the storage device. To avoid this data
inconsistency issue between a snapshot and original data, the user has to make the
operating system flushes the data from memory of the host (write cache) into disk before
taking snapshot.
Summary of Contents for XCubeSAN XS5224D
Page 71: ...SANOS User Interface 49 nnnnn RPM Power Supply Local PSU n status Reset to Default Yes No...
Page 99: ...System Settings 77 Figure 6 14 System Information...
Page 315: ...Monitoring 293 Figure 13 5 Hardware Monitoring...
Page 327: ...Support and Other Resources 305 Figure 15 1 Download Service Package in the SANOS UI...
Page 331: ...Support and Other Resources 309...