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

4. In the Cache Properties area, you can select:
– Enable read caching
– Enable write caching
* Enable write caching without batteries — to permit write caching to continue even if the
RAID controller module batteries are discharged completely, not fully charged, or are not
present.
* Enable write caching with mirroring — to mirror cached data across two redundant RAID
controller modules that have the same cache size.
– Enable dynamic cache read prefetch
CAUTION: Possible loss of data—Selecting the Enable write caching without batteries option
lets write caching continue even when the batteries are discharged completely or are not
fully charged. Typically, write caching is turned off temporarily by the RAID controller
module until the batteries are charged. If you select this option and do not have a universal
power supply for protection, you could lose data. In addition, you could lose data if you do
not have RAID controller module batteries and you select the Enable write caching without
batteries option.
NOTE: When the Optional RAID controller module batteries option is enabled, the Enable write
caching does not appear. The Enable write caching without batteries is still available, but it is
not checked by default.
NOTE: Cache is automatically flushed after the Enable write caching check box is disabled.
5. Click OK.
A message prompts you to confirm the change in the virtual disk modification priority.
6. Click Yes.
7. Click OK.
The Change Virtual Disk Propreties - Progress dialog is displayed.
Changing The Segment Size Of A Virtual Disk
You can change the segment size on a selected virtual disk. During this operation, I/O performance is
affected, but your data remains available.
Follow these guidelines to proceed with changing the segment size:
• You cannot cancel this operation after it starts.
• Do not start this operation unless the disk group is in Optimal status.
• The MD Storage Manager determines the segment size transitions that are allowed. Segment sizes
that are inappropriate transitions from the current segment size are unavailable on the menu. Allowed
transitions usually are double or half of current segment size. For example, if the current virtual disk
segment size is 32 KB, a new virtual disk segment size of either 16 KB or 64 KB is allowed.
NOTE: The operation to change the segment size is slower than other modification operations (for
example, changing RAID levels or adding free capacity to a disk group). This slowness is the result of
how the data is reorganized and the temporary internal backup procedures that occur during the
operation.
The amount of time that a change segment size operation takes depends on:
• The I/O load from the host
• The modification priority of the virtual disk
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