LaCie 131018 - StorView Snapshot - Mac, User Manual

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StorView RAID Module
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By default the “Show arrays used by this logical drive” is not selected. This is to deter the user from
selecting an array that comprise the logical drive’s arrays, as it is not the recommended choice. The
preferred method is to choose an array not associated with the logical drive. When the check box is
selected in addition to the other disk arrays, the arrays for this logical drive are shown as well and can be
selected.
6 Enter the size of the Overwrite Data Area in GBs.
It is highly recommended to consider future usage in order to determine the proper size to use based on
the number of expected snapshots. Capacity planning is vitally important. If the Overwrite Data Area
(ODA) size is exceeded, all snapshots associated with the logical drive become invalid.
7 From the drop-down menu, choose the desired stripe size (or write buffer size) for the Overwrite Data
Area (ODA). The choices are: 64KB, 128KB, 256KB, 512KB, or 1MB.
It is recommended that you choose a stripe size based on your application’s need. If you are making small
changes, such as with a database, then you will want the smallest stripe size. If you are making large
changes, such as with video application, then you will want a much larger stripe size.
Note The stripe sizes available in the drop-down menu will change dynamically based on the size of the ODA
entered. For example if you specify an ODA greater than 549 GBs, the selection for 64 Kb will not be
displayed. If you enter an ODA size greater than 1 terabyte, then both 64 Kb and 128 Kb stripe sizes will
not be displayed in the drop-down menu.
8 Click the ENABLE button.
9 You will see a confirmation window. Click the CLOSE button.
11.3 Taking a Snapshot
This process will take a point-in-time image of the selected logical drive. Snapshot’s are automatically
named, starting with “Snap 00” and will increment for each additional snapshot (Snap 01, Snap 02, etc.)
for that logical drive. You can view them from the Snapshot Information window.
Important You must ensure that applications writing to the logical drive are synchronized with the snapshot.
This can be performed in a variety of ways depending on the applications using the logical drive
where the snapshot is being initiated. Buffers may need to be flushed for a consistent point-in-
time image of the files on the logical drive.
1 From the Main screen select the logical drive to which you wish to take a snapshot.
Table 11–1 Overwrite Data Area (ODA) Stripe Sizes
Stripe Size Maximum Overwrite Data Area Size (ODA Size)
64 Kbytes 549 GBs
128 Kbytes 1 Terabyte
256 Kbytes 2 Terabytes
512 Kbytes 4 Terabytes
1 Mbyte 8 Terabytes