Hitachi MK-97DF8018-00 Monitoring SnapShot

7–2 Monitoring and Maintenance

Hitachi Simple Modular Storage Copy-on-Write SnapShot User’s Guide

Monitoring SnapShot

The SnapShot data pool must have sufficient capacity to handle the

differential data demands placed on it. You must insure that sufficient

capacity is always available for the write workload by closely monitoring the

following:

• Pair status

• Data pool usage

Monitoring Pair Status

To monitor pair status

(Advanced users using CLI, see the Storage Navigator Modular 2 Command

Line Interface (CLI) User’s Guide.)

1. In Navigator 2 GUI, select the desired array, then click the Show &

Configure Array button.

2. From the Replication tree, select the Local Replication icon. The Pairs

screen displays.

3. Locate the pair whose status you want to review in the Pair list, then

review the Status column. Click the Refresh Information button to

make sure the data is current.Statuses and definitions are listed in

Table 7-1.

•

Table 7-1: Pair Statuses

Pair Status Description Action

Simplex Status when the volume has not

have been paired or when the pair

has been deleted. The volume has

no SnapShot association with

another volume.

Paired V-VOL is a mirror image of the P-

VOL. Updates to the P-VOL are

copied to the V-VOL.

Reverse

Synchronizing

P-VOL restoration from V-VOL is in

progress.

Split The snapshot is executed.

Thresholdover Threshold value for the data pool is

exceeded; warning status.

Consider increasing data

pool capacity.

Failure Copying is suspended due to a

hardware failure or data pool

overflow. All V-VOLs become

invalid.

If d at a po ol o ve rfl ow i s t he

cause, increase data pool

capacity.

Contents

Main MK-97DF8018-00 Hitachi Simple Modular Storage Copy-on- Write SnapShot Users Guide ii Preface iv Document Revision Level Safety and Warnings Intended Audience Product Version Release Notes Document Organization Referenced Documents vi Document Conventions Convention for Storage Capacity Values Getting Help Support Contact Information Comments Page Table of Contents 1 SnapShot Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 2 Planning and Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 4 Enabling and Disabling SnapShot. . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 5 Configuring SnapShot. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 Page Page SnapShot Overview 12 Copy-on-Write SnapShot Software Hardware and Software Configuration Figure 1-1: SnapShot functional components How SnapShot Works 14 Volume PairsP-VOLs and V-VOLs Page 16 Data Pools Differential Management LUs (DM-LU) Consistency Group (CTG) SnapShot InterfaceStorage Navigator Modular 2 Planning and Design 22 The Plan and Design Workflow Assessing Business Needs Establishing How Often a Copy Is Made (Copy Frequency) Selecting a Reasonable Time Between Snapshots Establishing How Long a Copy Is Held (Copy Lifespan) Lifespan Based on Backup Requirements 24 Lifespan Based on Business Uses Figure 2-1: V-VOL Frequency, Lifespan Establishing the Number of V-VOLs that Are Required Establishing Data Pool Size Figure 2-2: Write workload and data pool size Measuring Workload Data 26 Figure 2-3: Raw Data Example in MB/sec Figure 2-4: Rolling Averages Calculated Using V-VOL Frequency Figure 2-5: Rolling Averages Graphed Over Raw Averages 28 Rule of Thumb Calculation Table 2-1: Workload Rates when No Measurement Data Pool Key Points Calculating Maximum Capacity 210 Operating System Considerations Identifying P-VOL and V-VOL Cluster Software, Path Switching Software Microsoft Cluster Server (MSCS) Veritas Volume Manager (VxVM) Windows 2000 Windows Server 2003 Linux and LVM Configuration Windows Server 2003/Windows 2000 and Dynamic Disk Page Page Requirements 32 System Requirements Supported Platforms Table 3-2 shows the supported platforms and operating system versions required for SnapShot. Table 3-1: Storage S Minimum Requirements Page 42 Enabling/Disabling SnapShot Page Page Configuring SnapShot 52 Configuration Workflow Assign Volumes for the Data Pool Notes on Adding a Data Pool Set Up the Virtual Volume (V-VOL) (manual method) Page Using SnapShot 62 SnapShot Replication Workflow Back Up Your VolumeCreate a Pair Using the Backup Wizard Create Pair Procedure 64 Update the V-VOL Restore the P-VOL from the V-VOL Restore from Tape 66 Use the V-VOL for Tape Backup, Testing, Reports, Etc. Edit Pairs, Data Pool Delete Pairs, V-VOLs, Data Pools 68 Test the Configuration Monitoring and Maintenance 72 Monitoring SnapShot Monitoring Pair Status Table 7-1: Pair Statuses Monitoring Data Pool Usage Expanding the Data Pool Other Methods for Lowering Data Pool Load Page Troubleshooting 82 Pair Failure Recovering from Pair Failure Due to POOL FULL Recovering from Pair Failure Due to a Hardware Failure Page Page A Operations Using CLI A2 Enabling and Disabling SnapShot Operations for SnapShot Configuration Setting the POOL A4 Setting the V-VOL Performing SnapShot CLI Operations Creating SnapShot Pairs A6 Updating SnapShot Logical Unit Restoring V-VOL to P-VOL Releasing SnapShot Pairs A8 Changing Pair Information Creating Pairs that Belong to a Group Operations Using CLI A9 Sample Back Up Script for Windows This section provides sample script for backing a volume on Windows. Page Page B2 General Specifications Table B-1 lists external specifications for SnapShot. Table B-1: General Specifications Item Specification Maximum Capacity on page 2-9 Table B-1: General Specifications Item Specification Page Glossary1 Glossary Glossary2 A B C Glossary3 Glossary4 Glossary5 D Glossary6 E F Glossary7 G I Glossary8 L Glossary9 M P Glossary10 Glossary11 R Glossary12 S Glossary13 T V W Glossary14 Index-1 Index A B C D Index-2 O P R S Page MK-97DF8018-00