WWR2 : About “capacity” and other key concepts : How Safeguarded Copy (SFC) affects capacity calculations : Adding a Safeguarded Copy backup
Adding a Safeguarded Copy backup
In the following example, we add a System 9200 system to a project and schedule Safeguarded Copy backups for the Pools that we define.
 
Note: By adding Safeguarded Copy backups to your design, you can compute the estimated cost of a Safeguarded Copy configuration for the pool.
a. Choose Storage in the left navigation pane. The system options are displayed to the right.
b. For this example, we click the System 9200 tile to add it to the project. The Systems > Systems tab for that system is displayed.
 
Note: The default settings for the Systems tab and the Adapters tab are OK for this example.
2. Click the Capacity tab, and click Add Pool. The Add Pool dialog box is displayed. Here, again, the default settings are OK for this example, except for the final option in the Add Pool dialog box. Click Submit.
3. Click Add Array for the Pool that you added in step 2. The Add Array dialog box is displayed. The default settings are OK for this example. Click Submit.
4. Click the three dots to the far-right of the pool that you added in step 2 and select Safeguarded Copy.
Figure 80 Safeguarded Copy option
The Add Safeguarded Copy dialog box is displayed.
Figure 81 Add Safeguarded Copy dialog box
5. Make the selections that represent the attributes of the system that you are designing. These selections are used to estimate the cost of Safeguarded Copy.
The following guidelines apply to specific fields:
 – Configure Safeguarded Copy for the pool: Turn this off if you want to disable the Safeguarded volume configuration in this pool without losing your previously entered attribute values. You can then re-enable Safeguarded volumes for this pool at a later time.
 
Note: The results of the Safeguarded Copy estimations are displayed at the top of the dialog, in a scrollable text area. Initially, the displayed results assume a minimal configuration. When you change the configuration attributes in the lower part of the dialog, the results are automatically updated. It is important to remember that the results are only estimates and can only be as accurate as the specified attributes.
 – Estimated Cost of Safeguarded backups and recovery volumes in this pool: Storage Modeller calculates the estimated cost in TiB and TB for both effective and usable capacity. It also considers the number of VDisks that will be consumed by the configuration. Note that Safeguarded source volumes are not considered a cost, so are not included.
 – Remaining Resources
Storage Modeller calculates the remaining resources in the pool and the system, after applying the estimated cost of the Safeguarded copy configuration.
 • The remaining capacity is available for any unprotected volumes in the pool.
 • The remaining VDisks are available for any unprotected volumes in this or other pools.
Note that multiple VDisks are consumed depending on the volume type; 1 per base volume, 2 per mirrored or GM-CV volume, and 4 per HyperSwap volume.
 – Potential loss due to malware:
Storage Modeller makes an educated guess as to which additional cost might be incurred if malware infects the host systems and encrypts the volumes. It is impossible to predict the effect that any given malware might have on the host or its storage. So, for the purpose of this estimation, Storage Modeller makes the following assumptions:
 • The malware operates by encrypting all data on the OS drives. Encryption is assumed to occur at the drive level, rather than the file-system level.
 • The malware makes only a single pass for encryption. It does not continually encrypt and re-encrypt the data.
The Storage Modeller itemizes this malware loss by source and by backup volumes. Source volumes will lose any benefit of data reduction. Backup volumes will cost an additional capacity equal to 100% of the source volumes, essentially a change rate of 100% for one backup per schedule.
It is important to note that Storage Modeller can estimate the potential malware loss ONLY for the Safeguarded volumes of each pool. The actual malware loss will be higher if the malware also affects other, unprotected volumes in the pool.
The user must decide whether to incorporate such potential malware losses into the system design, or whether to treat this as an exceptional condition that cannot or should not be planned for.
 – Type of Safeguarded Volumes in Pool: IBM Storage Virtualize does not currently allow Mirrored volumes to be configured as Safeguarded, though this limitation could change in the future.
 – Average Change Rate (in Effective capacity): Whenever you modify the Copy schedule (frequency) setting for Safeguarded Copy, you must reassess your entry for this field.
 
Note: The average change rate is highly dependent on the copy schedule.
6. Click Submit on the Add Safeguarded Copy dialog box. The Add Pool dialog box is displayed.
7. Click Submit on the Add Pool dialog box.
The new Pool is listed in the Capacity tab. The new Pool reflects the attributes that you specified for both the Add Pool dialog box and the Add Safeguarded Copy dialog box.
8. (Optional) Work with the shield icon that is displayed to the left of the new pool’s name:
 – Hover your mouse over the icon. You see the estimated cost of Safeguarded Copy for the pool.
 – Click on the shield icon to open the Add Safeguarded Copy dialog box again and review your settings.
Summary: Your action in these steps accounts for the cost of a Safeguarded Copy configuration in a pool that you create. This cost is an estimate only, and depends on the accuracy of the given attributes, especially the Average Change Rate. The performance impact of the configuration is not considered, because performance modelling of Copy devices is not yet supported in Storage Modeller.