Use the following matrix to calculate the number of target devices required for performing SnapProtect operations.
| Agent | Target Device Requirements (Business Continuance Volumes/ Shadow Image Volumes) | NOTES |
| full backup | incremental backup | differential backup | ||
| DB2 | [Number of devices where data resides] + [Number of devices where the online log resides] + [Number of devices where the 'LOCAL_DB_DIRECTORY' resides] + [Number of devices where the 'DBPATH' resides] | N/A | N/A | |
| Exchange Database | [Number of devices where data resides] + [Number of devices where the log resides] | [Number of devices where the log resides] | [Number of devices where the log resides] | For example, if your data resides on 2 devices, logs reside on 1 devices. Full backup will require 3(2+1) target devices, Incremental/Differential backup will require 1 target devices. |
| Microsoft SQL Server | [Number of devices where data resides] + [Number of devices where the log resides] | [Number of devices where data resides] + [Number of devices where the log resides] |
For example, if your file system data resides on 3 devices you will
require 3 target devices. SQL log backup does not require any target device. |
|
| Microsoft Windows File System | Number of devices on which the file system data resides | Number of devices on which the file system data resides | Number of devices on which the file system data resides | |
| NAS NDMP | Number of devices on which the file system data resides | |||
| Oracle | [Number of devices where data resides] + [Number of devices where the log resides] | N/A | ||
| Oracle – Data and logs residing on the same devices | 2x[Number of devices where data and logs reside] | N/A | For example, if your data and logs reside on 3 devices, you will require 6 target devices. | |
| Applications running on JFS | [Number of devices where application data resides] + [Number of devices where JFS logs reside] + [No. of devices on which logs reside] | N/A | For example, if your application data resides on 2 devices, logs reside on 1 devices, data and logs share one device, and JFS logs reside on 1 device, you will require 6 (2+1+2+1) target devices | |
| SAP for Oracle - Data and logs | [Number of devices where data resides] + [Devise where the 'sapbackup' directory resides] + [Number of devices where the log resides] + [Device where the 'saparch' directory resides] + 2 x [Device where the 'dbs' directory resides] | N/A | N/A | |
| Unix File System | [Number of devices where data resides] + [Number of devices where the log resides] | |||
| Unix File System on JFS | [Number of devices on which the file system data resides ] + [No. of devices on which file system logs reside] | For example, if your file system data resides on 2 devices and file system log resides on 1 device, you will require 3 target devices. | ||
| VMware | Number of luns on which the datastore for the VM resides | Number of luns on which the datastore for the VM resides | N/A | |
| Microsoft Hyper-V | Number of luns on which vhd and configuration files of VM reside | Number of luns on which vhd and configuration files of VM reside | N/A |
Hardware specific revert operations of VSP volumes may fail if system MODE 80 and MODE 87 options are set to ON in the array. It is recommended to have these modes always OFF for hardware reverts to succeed.
Please note that by default MODE 80 and MODE 87 are set to OFF. After installing the storage array software, all system modes are set to their default values by default. System modes can only be changed by a Hitachi Data Systems representative.
You cannot switch between HDS Snap and HDS Clone on the same disk; even after deleting the existing snaps.
The maximum number of snapshots created for a USP volume is 3.
Yes, you can reuse a deleted Shadow Image by creating the CVHDS_USE_DELETED_SHADOWIMAGE registry key if you encounter one of the following scenarios:
For P-VOL, the first COW pair creation determines the device pool selection. The pool-id specified during the first COW pair is used for all the remaining COW pairs created using the same P_VOL. If you specify another pool-id during the creation it will be ignored and the pool-id specified during the first COW pair creation will be used.
Ensure that enough disk space is available for snapshot operations and the disk space used by snapshots is monitored. The space requirement for snapshots created during SnapProtect backup can vary based on your environment. The space utilization is dependent on the number of snapshots created and the retention period defined for the snapshots.
In order to use a specific initiator for accessing snapshots during SnapProtect backup set the sSNAP_UseINITIATOR registry key to the desired initiator address.