User Manual
Table Of Contents
- Dell PowerVault MD 34XX/38XX Series Storage Arrays Administrator's Guide
- Introduction
- About Your MD Series Storage Array
- Physical Disks, Virtual Disks, And Disk Groups
- Disk Pools
- Thin Virtual Disks
- RAID Levels
- Segment Size
- Virtual Disk Operations
- Disk Group Operations
- RAID Background Operations Priority
- Virtual Disk Migration And Disk Roaming
- Advanced Features
- Multi-Path Software
- Load Balancing
- Monitoring System Performance
- Interpreting Performance Monitor Data
- Viewing Real-time Graphical Performance Monitor Data
- Customizing the Performance Monitor Dashboard
- Specifying Performance Metrics
- Viewing Real-time Textual Performance Monitor
- Saving Real-time Textual Performance Data
- Starting and Stopping Background Performance Monitor
- Viewing Information about the Current Background Performance Monitor Session
- Viewing Current Background Performance Monitor Data
- Saving the Current Background Performance Monitor Data
- Viewing Saved Background Performance Monitor Data
- What are invalid objects in the Performance Monitor?
- Discovering And Managing Your Storage Array
- Out-Of-Band Management
- In-Band Management
- Storage Arrays
- Setting Up Your Storage Array
- Locating Storage Arrays
- Naming Or Renaming Storage Arrays
- Setting A Password
- Adding Or Editing A Comment To An Existing Storage Array
- Removing Storage Arrays
- Enabling Premium Features
- Displaying Failover Alert
- Changing The Cache Settings On The Storage Array
- Changing Expansion Enclosure ID Numbers
- Changing The Enclosure Order
- Configuring Alert Notifications
- Battery Settings
- Setting The Storage Array RAID Controller Module Clocks
- Using iSCSI
- Changing The iSCSI Target Authentication
- Entering Mutual Authentication Permissions
- Creating CHAP Secrets
- Changing The iSCSI Target Identification
- Changing The iSCSI Target Discovery Settings
- Configuring The iSCSI Host Ports
- Advanced iSCSI Host Port Settings
- Viewing Or Ending An iSCSI Session
- Viewing iSCSI Statistics And Setting Baseline Statistics
- Edit, Remove, Or Rename Host Topology
- Event Monitor
- About Your Host
- Disk Groups, Standard Virtual Disks, And Thin Virtual Disks
- Creating Disk Groups And Virtual Disks
- Thin Virtual Disks
- Advantages Of Thin Virtual Disks
- Physical Vs Virtual Capacity On A Thin Virtual Disk
- Thin Virtual Disk Requirements And Limitations
- Thin Volume Attributes
- Thin Virtual Disk States
- Comparison—Types Of Virtual Disks And Copy Services
- Rollback On Thin Virtual Disks
- Initializing A Thin Virtual Disk
- Changing A Thin Virtual Disk To A Standard Virtual Disk
- Choosing An Appropriate Physical Disk Type
- Physical Disk Security With Self Encrypting Disk
- Configuring Hot Spare Physical Disks
- Enclosure Loss Protection
- Drawer Loss Protection
- Host-To-Virtual Disk Mapping
- Creating Host-To-Virtual Disk Mappings
- Modifying And Removing Host-To-Virtual Disk Mapping
- Changing Controller Ownership Of The Virtual Disk
- Removing Host-To-Virtual Disk Mapping
- Changing The RAID Controller Module Ownership Of A Disk Group
- Changing The RAID Level Of A Disk Group
- Removing A Host-To-Virtual Disk Mapping Using Linux DMMP
- Restricted Mappings
- Storage Partitioning
- Disk Group And Virtual Disk Expansion
- Disk Group Migration
- Storage Array Media Scan
- Disk Pools And Disk Pool Virtual Disks
- Difference Between Disk Groups And Disk Pools
- Disk Pool Restrictions
- Creating A Disk Pool Manually
- Automatically Managing The Unconfigured Capacity In Disk Pools
- Locating Physical Disks In A Disk Pool
- Renaming A Disk Pool
- Configuring Alert Notifications For A Disk Pool
- Adding Unassigned Physical Disks To A Disk Pool
- Configuring The Preservation Capacity Of A Disk Pool
- Changing The Modification Priority Of A Disk Pool
- Changing The RAID Controller Module Ownership Of A Disk Pool
- Checking Data Consistency
- Deleting A Disk Pool
- Viewing Storage Array Logical Components And Associated Physical Components
- Secure Disk Pools
- Changing Capacity On Existing Thin Virtual Disks
- Creating A Thin Virtual Disk From A Disk Pool
- Using SSD Cache
- How SSD Cache Works
- Benefits Of SSD Cache
- Choosing SSD Cache Parameters
- SSD Cache Restrictions
- Creating An SSD Cache
- Viewing Physical Components Associated With An SSD Cache
- Locating Physical Disks In An SSD Cache
- Adding Physical Disks To An SSD Cache
- Removing Physical Disks From An SSD Cache
- Suspending Or Resuming SSD Caching
- Changing I/O Type In An SSD Cache
- Renaming An SSD Cache
- Deleting An SSD Cache
- Using The Performance Modeling Tool
- Premium Feature—Snapshot Virtual Disk
- Snapshot Virtual Disk Vs. Snapshot Virtual Disk (Legacy)
- Snapshot Images And Groups
- Snapshot Virtual Disk Read/Write Properties
- Snapshot Groups And Consistency Groups
- Understanding Snapshot Repositories
- Creating Snapshot Images
- Scheduling Snapshot Images
- Performing Snapshot Rollbacks
- Creating A Snapshot Group
- Converting A Snapshot Virtual Disk To Read-Write
- Viewing Associated Physical Components Of An Individual Repository Virtual Disk
- Creating A Consistency Group
- Creating A Snapshot Virtual Disk Of A Snapshot Image
- Snapshot Virtual Disk Limitations
- Creating A Snapshot Virtual Disk
- Creating A Snapshot Virtual Disk Repository
- Changing The Settings Of A Snapshot Virtual Disk
- Disabling A Snapshot Virtual Disk Or Consistency Group Snapshot Virtual Disk
- Re-creating A Snapshot Virtual Disk Or Consistency Group Snapshot Virtual Disk
- Renaming A Snapshot Virtual Disk Or Consistency Group Snapshot Virtual Disk
- Deleting A Snapshot Virtual Disk Or Consistency Group Snapshot Virtual Disk
- Creating A Consistency Group Snapshot Virtual Disk
- Creating A Consistency Group Snapshot Virtual Disk Repository (Manually)
- Disabling A Snapshot Virtual Disk Or Consistency Group Snapshot Virtual Disk
- Re-creating A Snapshot Virtual Disk Or Consistency Group Snapshot Virtual Disk
- Changing The Modification Priority Of An Overall Repository Virtual Disk
- Changing The Media Scan Setting Of An Overall Repository Virtual Disk
- Changing The Pre-read Consistency Check Setting Of An Overall Repository Virtual Disk
- Increasing The Capacity Of An Overall Repository
- Decreasing The Capacity Of The Overall Repository
- Performing A Revive Operation
- Premium Feature—Snapshot Virtual Disks (Legacy)
- Scheduling A Snapshot Virtual Disk
- Creating A Snapshot Virtual Disk Using The Simple Path
- Creating A Snapshot Virtual Disk Using The Advanced Path
- Specifying Snapshot Virtual Disk Names
- Snapshot Repository Capacity
- Re-Creating Snapshot Virtual Disks
- Disabling A Snapshot Virtual Disk
- Re-Creating A Snapshot Virtual Disk
- Premium Feature—Virtual Disk Copy
- Using Virtual Disk Copy With Snapshot Or Snapshot (Legacy) Premium Feature
- Types Of Virtual Disk Copies
- Creating A Virtual Disk Copy For An MSCS Shared Disk
- Virtual Disk Read/Write Permissions
- Virtual Disk Copy Restrictions
- Creating A Virtual Disk Copy
- Preferred RAID Controller Module Ownership
- Failed RAID Controller Module
- Copy Manager
- Copying The Virtual Disk
- Storage Array Performance During Virtual Disk Copy
- Setting Copy Priority
- Stopping A Virtual Disk Copy
- Recopying A Virtual Disk
- Removing Copy Pairs
- Device Mapper Multipath For Linux
- Configuring Asymmetric Logical Unit Access
- Premium Feature—Remote Replication
- About Asynchronous Remote Replication
- Remote Replicated Pairs And Replication Repositories
- Types Of Remote Replication
- Remote Replication Requirements And Restrictions
- Setting Up Remote Replication
- Activating Remote Replication Premium Features
- Deactivating Remote Replication
- Remote Replication Groups
- Replicated Pairs
- Management Firmware Downloads
- Downloading RAID Controller And NVSRAM Packages
- Downloading Both RAID Controller And NVSRAM Firmware
- Downloading Only NVSRAM Firmware
- Downloading Physical Disk Firmware
- Downloading MD3060e Series Expansion Module EMM Firmware
- Self-Monitoring Analysis And Reporting Technology (SMART)
- Media Errors And Unreadable Sectors
- Firmware Inventory
- System Interfaces
- Storage Array Software
- Start-Up Routine
- Device Health Conditions
- Trace Buffers
- Collecting Physical Disk Data
- Event Log
- Recovery Guru
- Storage Array Profile
- Viewing The Physical Associations
- Recovering From An Unresponsive Storage Array Condition
- Locating A Physical Disk
- Locating An Expansion Enclosure
- Capturing The State Information
- SMrepassist Utility
- Unidentified Devices
- Recovering From An Unidentified Storage Array
- Starting Or Restarting The Host Context Agent Software
- Getting Help

10
Premium Feature—Snapshot Virtual Disk
The following types of virtual disk snapshot premium features are supported on the MD storage array:
• Snapshot Virtual Disks using multiple point-in-time (PiT) groups
• Snapshot Virtual Disks (Legacy) using a separate repository for each snapshot
NOTE: This section describes the Snapshot Virtual Disk using PiT groups. If you are using the
Snapshot Virtual Disk (Legacy) premium feature, see Premium Feature—Snapshot Virtual Disks
(Legacy).
A snapshot image is a logical image of the content of an associated base virtual disk created at a specific
point-in-time, often known as a restore point. This type of image is not directly readable or writable to a
host since the snapshot image is used to save data from the base virtual disk only. To allow the host to
access a copy of the data in a snapshot image, you must create a snapshot virtual disk. This snapshot
virtual disk contains its own repository, which is used to save subsequent modifications made by the host
application to the base virtual disk without affecting the referenced snapshot image.
Snapshot Virtual Disk Vs. Snapshot Virtual Disk (Legacy)
Any snapshot virtual disk image is a logical point-in-time image of a virtual disk. However, the Snapshot
Virtual Disk premium feature differs from the Snapshot Virtual Disk (Legacy) premium feature in the
following ways:
• The Snapshot Virtual Disk (Legacy) premium feature uses one data repository for each snapshot. The
non-legacy Snapshot Virtual Disk premium feature uses one data repository for all snapshot images
associated with a base virtual disk. As a result, only one write operation per virtual disk is required (not
multiple sequential write operations).
• Snapshot Virtual Disk adds the concept of a snapshot group. Because there is only one repository for
multiple snapshot images, the repository is associated with the snapshot group instead of with the
snapshot image.
• Unlike a Snapshot Virtual Disk (Legacy), a snapshot image created with the Snapshot Virtual Disk
premium feature is not directly read/write accessible by a host since the snapshot image is used only
to save changed data for a base virtual disk.
• Either Snapshot Virtual Disk or Snapshot Virtual Disk (Legacy) images can be created from a base
virtual disk, but not both.
• A snapshot image created using Snapshot Virtual Disk is created almost instantaneously and initially
uses no disk space.
• Snapshot Virtual Disk images are always created inside snapshot groups; each snapshot image is
associated with only one snapshot group.
Snapshot Images And Groups
Snapshot images can be created manually or automatically by establishing a schedule that defines the
date and time you want the snapshot image created. The following objects can be included in a snapshot
image:
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