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
A consistency check is similar to a background initialization. The difference is that background
initialization cannot be started or stopped manually, while consistency check can.
NOTE: It is recommended that you run data consistency checks on a redundant array at least once
a month. This allows detection and automatic replacement of unreadable sectors. Finding an
unreadable sector during a rebuild of a failed physical disk is a serious problem, because the system
does not have the redundancy to recover the data.
Media Verification
Another background task performed by the storage array is media verification of all configured physical
disks in a disk group. The storage array uses the Read operation to perform verification on the space
configured in virtual disks and the space reserved for the metadata.
Cycle Time
The media verification operation runs only on selected disk groups, independent of other disk groups.
Cycle time is the time taken to complete verification of the metadata region of the disk group and all
virtual disks in the disk group for which media verification is configured. The next cycle for a disk group
starts automatically when the current cycle completes. You can set the cycle time for a media verification
operation between 1 and 30 days. The storage controller throttles the media verification I/O accesses to
disks based on the cycle time.
The storage array tracks the cycle for each disk group independent of other disk groups on the controller
and creates a checkpoint. If the media verification operation on a disk group is preempted or blocked by
another operation on the disk group, the storage array resumes after the current cycle. If the media
verification process on a disk group is stopped due to a RAID controller module restart, the storage array
resumes the process from the last checkpoint.
Virtual Disk Operations Limit
The maximum number of active, concurrent virtual disk processes per RAID controller module installed in
the storage array is four. This limit is applied to the following virtual disk processes:
• Background initialization
• Foreground initialization
• Consistency check
• Rebuild
• Copy back
If a redundant RAID controller module fails with existing virtual disk processes, the processes on the failed
controller are transferred to the peer controller. A transferred process is placed in a suspended state if
there are four active processes on the peer controller. The suspended processes are resumed on the peer
controller when the number of active processes falls below four.
Disk Group Operations
RAID Level Migration
You can migrate from one RAID level to another depending on your requirements. For example, fault-
tolerant characteristics can be added to a stripe set (RAID 0) by converting it to a RAID 5 set. The MD
Storage Manager provides information about RAID attributes to assist you in selecting the appropriate
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