Hitachi uses the Hitachi Dynamic Link Manager (HDLM) to manage multiple-path I/O. HDLM is implemented as a Microsoft MPIO DSM which is onto the application host server.
The two paths are assigned to the same iSCSI initiator in the HDLM software so that the iSCSI initiator software can take advantage of the multi-path options.
The Microsoft iSCSI initiator software is then configured for multi-path in the standard fashion.
Basic Performance Results
The following performance data is not intended to be viewed as a comprehensive performance benchmark, but to provide a general performance overview for the HDS TagmaStore AMS1000 Solution. Performance will vary depending on drive speeds, number of drives, applications and many other factors.
HDS has a significant body of performance information available that will accurately represent the performance ability of the AMS 1000. Please contact HDS for more detailed performance data.
Selected performance results are shown below, using a standard server-class network adapter, with receive-side scaling on the host. This configuration used two paths from one host, four I/O workers, accessing four target volumes and a queue depth of 10.
HP StorageWorks 1200 All-in-One Storage System
The HP StorageWorks 1200 All-in-One Storage System (AiO1200) is based on Microsoft Windows Storage Server 2003 R2 (WSS) and the Microsoft iSCSI software target. It is a unified NAS device and iSCSI target solution which also includes integrated data protection software and a management console designed for IT generalists who may be new to storage configuration. The AiO1200 is built on the HP ProLiant hardware platform and has a disk subsystem of 12 internal SATA or SAS disk drives available in various storage capacities. The HP All-in-One Storage System is also available in 4 and 6 drive configurations all of which support external storage expansion to direct attach storage enclosures. The version tested for this report included 12 drives and 3.6 terabytes (TB) of raw storage capacity.
The HP All-in-One Storage Manager (ASM) is a unique toolset which is included in the AiO and is designed to reduce the time, expense, and expertise required to deploy and manage storage resources. ASM hides much of the complexity traditionally associated with storage configuration and presents storage in an application-centric context rather than a storage-centric view. The toolset integrates with several Microsoft applications and includes data migration tools for Exchange Server 2003/2007 and SQL Server 2000/2005. The following configuration steps will illustrate how storage can be configured using ASM or how other system-level tools can be used for more granular control.
Target Configuration Steps
Configure Network Settings for iSCSI Target Device
The main HP All-in-One management console includes a “Rapid Startup Wizard” which automatically launches at first boot and is used to simplify initial system configuration.
The Rapid Startup Wizard includes a place to set the network configuration. This system was configured to use DHCP on its three Ethernet network interfaces.
Launch Management Console
All the storage management functions for the HP StorageWorks 1200 All-in-One Storage System are performed from the management console, shown below.
In the center section of the management console, several categories of management functions are available.
Guided configuration: Link to the All-in-One Storage Manager (ASM)
ASM is an ‘application-centric’ management interface into the file shares and iSCSI target storage on the AiO and shows capacity usage in terms of managed data areas. ASM exists as the first node in the management console tree. The main ASM management screen is shown below.
The interface includes several wizards which automate configuration, provisioning, and data migration. These include
Prior to launching any of the interface wizards, administrators will need to install an ASM agent onto their host server (Windows Server 2003 32-bit or 64-bit). This agent packages the Microsoft iSCSI initiator, an ASM Service which runs on the host, as well as some Microsoft .NET components to enable communication between the host server and the AiO. The agent installation process also sets up application specific security parameters for SQL Server and Exchange.
As an example of the guided configuration capabilities of the AiO we will walk you through the ‘Host an Exchange Storage Group” tool.
Clicking the link on the right side of the interface launches the wizard. The first input screen asks the administrator to specify the Name or IP address of the Microsoft Exchange server where they have installed the ASM Agent.
Clicking NEXT enables ASM to communicate with the service on the host server and brings up the ‘Select Storage Group Components’ screen. The service uses the Microsoft Exchange API to gather data about the installation and return it to the AiO administrator. Specifically, the administrator is prompted to choose the Storage Group(s) which need to be moved to the iSCSI target storage.
Clicking NEXT brings up the Storage Allocation screen. Here, ASM has recommended a set of storage settings based on Microsoft ‘best practices’ for Exchange; these include RAID type, stripe settings, exclusive disk use, warning threshold, etc. Administrators can accept these settings or click the Advanced button to manually override. They can also choose between HDD technologies (SATA and/or SAS) if both disk types reside on the AiO or any direct attached storage enclosures.
Clicking on the Data Protection button brings up a screen that allows administrators to configure VSS snapshots for this iSCSI Target storage and to configure a traditional backup job using the HP Data Protector Express software which is included on the AiO.
Clicking NEXT will bring up a task summary of the steps that ASM will automatically perform. Tasks can be run immediately or scheduled for later; in the case of data migration the process will tell the Exchange server to temporary halt the service so that data can be migrated to the newly created iSCSI LUNs and will then restart the service.
Create iSCSI LUN and connect the host to the target
Create and format the iSCSI volume
Set directory quotas and alerts on the iSCSI target storage
Migrate storage group components
Create the backup job
Once the job is executed, storage tasks such as expansion and protection of the Storage Group can be managed from the main ASM interface as shown below.
NOTE: Remaining steps 4 through 8 illustrate how to manually configure iSCSI target storage outside of the All-in-One Storage Manager. If using ASM, steps 4 through 9 are performed automatically by the various ASM application tools.
Manual configuration if not using ASM (Steps 4 through 9):
To create the LUNs on the Disk Array, the administrator selects the “Array Configuration Utility” scenario from the “Storage Management” section of the management console. This launches the array configuration utility.
Highlighting the “Create Array” menu item allows the creation of a data volume across the unassigned drives in the system. All ten of the unassigned drives will be used for the iSCSI data volumes.
Clicking “Create Logical Drive” displays the options for Logical Drive creation, including RAID type and size. We create a logical drive of the type RAID 1 0 and use all the available space.
Note – It is important at this point to note that the storage solution LUN size should not be confused with the size of the iSCSI target. The iSCSI target will be configured in a later step and is associated with the storage needed for a particular application on the host server. It is recommended that the LUN size on the storage hardware be as large as reasonably possible to allow the storage subsystem to optimize the use of the physical disks underlying the LUN that is created. In this case, as shown below, we are choosing to create one LUN at the maximum size available for this hardware. The iSCSI targets created later will fit into this one LUN, based on the needs of the host application.
This configuration is saved.
The final configuration is displayed.
Make LUNs Ready for Use
Because this storage solution is running on a Microsoft Windows-based platform, the remaining steps would be familiar to a Windows administrator. These include assigning a drive letter for the internal server, providing a volume name, etc. These are prompted by using the standard Disk Management function from the management console.
The LUN has now been created. The next step is to create a partition on the LUN and format it in the normal manner that Windows administrators would expect.
We choose the maximum available size for the new partition. We want Windows to manage the entire partition as one entity.
The LUN is now ready for use. The next step will create iSCSI targets and associate them with this newly-created LUN.
Create iSCSI Targets
Clicking on the Microsoft iSCSI target function in the Storage Management section of the management console begins the iSCSI target creation process.
The iSCSI target window opens, and the iSCSI target creation wizard is started by using the right mouse click button.
We will create a total of four targets, two associated with host number one and two associated with host number two. The individual steps to create the first target are shown below.
Because there have been no previous iSCSI initiators assigned to this target, the initiators must be specifically identified.
The initiators will be identified by their IP address.
The target now appears in the target list of the iSCSI target management window.
The management console also shows the underlying devices available for the iSCSI targets. The storage that will be used by the iSCSI initiators (application hosts) will be defined in a later step when the virtual disks are created.
Create Multi-path I/O for iSCSI Targets (optional)
For a Microsoft-based target solution, multiple paths to the target device are created by providing multiple iSCSI initiator identifiers for the same target. In the example above, we add a second and third IP address that is to be associated with the same iSCSI initiator, so that there are three IP addresses that can access the target. These three addresses are associated with three Ethernet ports on the same host server.
Configure Security for iSCSI Targets (optional)
If security is desired for the iSCSI communication between the initiator and the target, the CHAP secret can be entered in the Authentication tab.
Make iSCSI Targets Ready for Use for iSCSI Initiators
Virtual disks need to be created on the iSCSI targets for Microsoft-based iSCSI target solutions. These virtual disks represent the storage volumes that the iSCSI initiators will use. The maximum capacity represented by all the virtual disks on a given iSCSI target on a Microsoft-based iSCSI target solution is two terabytes (2 TB) per target. In this example, we create a 100 GB and 200 GB virtual disk for each of the two iSCSI targets. These virtual disks will be viewed as volumes by the iSCSI initiators over the TCP/IP network.
By right-clicking on the target name, the “Create Virtual Disk” wizard is launched.
The virtual disk is created on the internal disk volume that is available to the iSCSI target. In this case, it is the “P” volume.
The size of the virtual disk depends on the needs of the application on the host server. For this virtual disk, we choose a size of 100 GB from the available 1.34 TB on this volume.
A description, although optional, is useful for better management.
This virtual disk must be associated with an iSCSI target in order for the application host to use this storage as an iSCSI storage volume.
This completes the virtual disk configuration.
We repeat this process to create three more virtual disks. After configuring the virtual disks, the management console shows the virtual disks associated with each iSCSI target.