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Dell PowerVault Modular Disk 3000 Systems Installation Guide
Verifying Storage Array Discovery
Before using the MD3000 storage array for the first time, you must complete a number of initial configuration tasks in the order shown. These tasks can be performed from any system (host or management station) on which you have installed MD Storage Manager software.
|NOTE: Advanced Configuration for MD Storage Manager (Tools® Change Network Configuration® Configure Ethernet Management Ports) should only be attempted with Dell technical assistance.|
|NOTE: You can set the network configuration using a DHCP server.|
|NOTE: You can also launch MD Storage Manager in Linux by entering the following commands at the command prompt:|
|NOTE: It may take several minutes for the discovery process to complete. Closing the Automatic Discovery status window before then stops the discovery process.|
After discovery is complete, a confirmation screen appears. Click Close to close the screen.
|NOTE: Before configuring the storage array, check the status icons on the Summary tab to make sure the enclosures in the storage array are in an Optimal status. For more information on the status icons, see Troubleshooting Tools.|
Table 4-1. Initial Setup Tasks Dialog Box
Rename the storage array.
NOTE: If you need to physically find the device, click Blink the storage array on the Initial Setup Tasks dialog box or click the Tools tab and choose Blink. Lights on the front of the storage array blink intermittently to identify the array. Dell recommends blinking storage arrays to ensure that you are working on the correct enclosure.
To provide a more meaningful name than the software-assigned label of Unnamed
A unique, clear name with no more than 30 characters that may include letters, numbers, and no special characters other than underscore (_), minus (), or pound sign (#)
NOTE: MD Storage Manager does not check for duplicate names. Names are not case sensitive.
Set a storage array password.
To restrict unauthorized access, MD Storage Manager asks for a password before changing the configuration or performing a destructive operation
Case-sensitive password that meets your security standards
Set up alert notifications.
Set up e-mail alerts.
Set up SNMP alerts.
NOTE: The Notification Status line in the Summary screen Status area shows if alerts have been set for the selected array.
To arrange to notify individuals (by e-mail) and/or storage management stations (by SNMP) when a storage array component degrades or fails, or an adverse environmental condition occurs
E-mail Sender (sender's SMTP gateway and e-mail address) and recipients (fully qualified e-mail addresses)
SNMP (1)community name, a known set of storage management stations, set by administrator as an ASCII string in the management console (default: "public") and (2) trap destination, IP address or host name of a management console running an SNMP service
Configure host access.
Allow access to virtual disks for certain or all hosts
Host and host group names, types, and operating systems
HBA host port ID numbers, if necessary
NOTE: You may need to refer to the documentation that came with your cards to identify the host ports. For maximum redundancy, select all HBAs connected to the array during manual setup. For example, a host might have two HBAs, each connected to the array. Specify each connected HBA host port.
Configure storage array (2 options).
To allow you to create virtual disks, to map them to hosts, and to create hot spares to automatically replace physical disks marked as Failed. Choose the items under Automatic configuration if you want uniformly sized virtual disks of the same RAID level.
Automatic (1) Uniform RAID level and (2) host names for mapping
Manual (1) Whether virtual disk uses unconfigured space or free capacity, (2) physical disk type, (3) size, and (4) RAID level
For a Linux host:
For Windows, virtual disks are automatically registered.
The Automatic Discovery option automatically discovers both in-band and out-of-band arrays and adds the storage arrays to the management domain. If the out-of-band or in-band connections shown on the Summary page are not accurate, complete the following steps. For more information, refer to the MD Storage Manager User's Guide or MD Storage Manager online help.
On Linux, click the Manual button and click OK.
Multi-path drivers select the I/O path to a virtual disk through a specific RAID controller module. When the multi-path driver receives a new I/O, the driver tries to find a path to the current RAID controller module that owns the virtual disk. If that path cannot be found, the multi-path driver migrates the virtual disk ownership to the secondary RAID controller module. When multiple paths to the RAID controller module that owns the virtual disk exist, you can choose a load balance policy to determine which path is used to process I/O. Multiple options for setting the load balance policies let you optimize I/O performance when mixed host interfaces are configured.
You can choose one of these load balance policies to optimize I/O performance:
The round-robin with subset I/O load balance policy routes I/O requests, in rotation, to each available data path to the RAID controller module that owns the virtual disks. This policy treats all paths to the RAID controller module that owns the virtual disk equally for I/O activity. Paths to the secondary RAID controller module are ignored until ownership changes. The basic assumption for the round-robin policy is that the data paths are equal. With mixed host support, the data paths might have different bandwidths or different data transfer speeds.
The least queue depth with subset policy is also known as the least I/Os, or least requests, policy. This policy routes the next I/O request to a data path that has the least outstanding I/O requests queued. For this policy, an I/O request is simply a command in the queue. The type of command or the number of blocks that are associated with the command are not considered. The least queue depth with subset policy treats large block requests and small block requests equally. The data path selected is in the path group of the RAID controller module that owns the virtual disk.
The least path weight with subset policy assigns a weight factor to each data path to a virtual disk. An I/O request is routed to the path with the lowest weight value to the RAID controller module that owns the virtual disk. If more than one data path to the virtual disk has the same weight value, the round-robin with subset path selection policy is used to route I/O requests between paths with the same weight value. The least path weight with subset load balance policy is not supported on Linux operating systems.
Two options are available for setting the load balance policies for the Linux operating system:
|NOTE: The only load balancing policy options for Linux are 0x0 (round robin) and 0x1 (least queue depth).|
The mppUtil command includes the option of implementing the changes immediately; however, changes do not persist after rebooting the host.
mppUtil -o LoadBalancePolicy=n
where n is 0 for round robin or 1 for least queue depth. This change takes effect immediately and affects only the in-memory state of the load balance policy. The change will not persist after rebooting the host.
Once you have successfully run the mppUtil command, your load balancing steps are complete. You do not need to continue from here.
mppUtil -o LoadBalancePolicy=n, SaveSettings
where n is 0 for round robin or 1 for least queue depth. The SaveSettings parameter lets the load balance setting persist after rebooting the host. Go to step 6 to complete the procedure.
The mppUpdate command rebuilds the RAM disk image with the new load balance policy settings. The new settings will be used after rebooting the host.
Load balancing with the MD3000 is only available for Windows Server 2008 and later versions of the operating system. You can change the load balance policies from the default round robin with subset by using one of the following:
Premium features supported by MD Storage Manager include:
To install and enable these premium features, you must first purchase a feature key file for each feature and then specify the storage array that will host them. The Premium Feature Activation Card that shipped in the same box as your MD3000 gives instructions for this process.
For more information on using these premium features, see the MD Storage Manager User's Guide.
The MD Storage Manager establishes communication with each managed array and determines the current array status. When a problem occurs on a storage array, MD Storage Manager provides several ways to troubleshoot the problem:
|NOTE: A SAS Device Miswire Recovery Guru condition can be generated by connecting the host port of one controller to the unused expansion port on the other controller in a MD3000 enclosure. After fixing the miswire condition, power cycle the MD3000 to clear the Recovery Guru condition.|
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