SSDs for High-End IBM DS8700

The IBM System Storage DS8700 (machine types 2421, 2422, 2423, and 2424) from IBM Corp. is designed to deliver new Easy Tier solid-state storage optimization, advanced business continuity features, and new drive options that double the system’s overall capacity.



 
New options include:

• IBM System Storage Easy Tier – Automates data placement throughout the DS8700 disk pool (including multiple drive tiers) to intelligently align the system with current workload requirements. This includes the ability for the system to automatically and nondisruptively relocate data (at the extent level) across drive tiers, and the ability to manually relocate full volumes.
• Eight drive install group of Solid State Disk (SSD) – Offers the support of eight drive install group of SSD (half disk drive set), providing additional price/performance and capacity flexibility to help address application and business requirements.
• 600 GB 15,000 rpm Fibre Channel Disk Drive – Provides additional capacity and price/performance option especially beneficial for transaction processing workloads.
• SATA drive support – Provides 2 TB 7,200 rpm SATA disk drives to support fixed-content, data-archival, reference-data, and other applications that require large amounts of storage capacity at lower cost per MB. Supported RAID configurations are RAID-6 and RAID-10.
• Quick initialization and Thin Provisioning – IBM System Storage DS8700 supports quick volume initialization and Thin Provisioning for open system environments, which can help increase disk capacity utilization, thereby supporting lower costs.
• Remote Pair FlashCopy – Provides management improvement to resiliency solutions by improving data synchronization when a FlashCopy target is also a Metro Mirror source. This keeps the local and remote site consistent which facilitates recovery, supports HyperSwap, and reduces link bandwidth utilization.
• Concurrent code load improvements – Splitting code load phases (the Acquire/Distribution from Activation). The Acquire/Distribution phase can be done earlier and the Activation phase can be done later. This will allow for a less than 2-hour activation phase of the main components of the DS8700. Once installed, this capability will be enabled when moving forward to future levels of code.
• Prevent deletion of CKD and FB volumes in use – The DS8700 now supports additional measures to prevent online devices from deletion.
• Disable recovery key – With security administrator access, encryption group recovery key is optionally disabled, or configured, before establishing initial logical configuration.
• Rekey data keys of an encryption group – With security administrator access, users can rekey the data keys of their encryption group. Both of these enhancements can help clients satisfy PCI (Payment Card Industry) security standards.
• z/HPF extended distance – Reduces the impact associated with supported commands on current adapter hardware, thereby improving FICON throughput on the DS8700 I/O ports.

All features and functions in this announcement are supported on the IBM System Storage DS8000 series, and require DS8000 Licensed Machine Code (LMC) level 6.5.1.xx (bundle version 75.1.xx.xx), or later.

Planned availability date: May 21, 2010

IBM System Storage Easy Tier
IBM System Storage Easy Tier is designed to help automate data placement throughout the DS8700 disk pool (including multiple drive tiers) to intelligently align the system with current workload requirements. This includes the ability for the system to automatically and nondisruptively relocate data (at the extent level) across drive tiers, and the ability to manually relocate full volumes. The benefit is to align performance of the system with the appropriate application workloads.

Automated relocation
While SSDs can provide higher performance for most workloads, they do so at a significantly higher cost than traditional spinning drives. Even with recent improvements in the cost of SSDs, they remain an expensive option for many workloads, especially those requiring large amounts of storage. Based on those higher costs, it is often not realistic to replace all spinning drives with SSDs for a given application or workload. In order to improve performance of SSDs and reduce overall system cost, infrequently accessed (cold) data can and should reside on lower cost HDDs while frequently accessed (hot) data should be moved to SSDs. The mix of SSDs and HDDs should be used to strike a proper balance between performance and cost.

IBM System Storage DS8700 introduces this capability with IBM System Storage Easy Tier. Easy Tier provides the ability to manage data placement between two tiers of storage, SSD and either Fiber Channel or SATA drives. Using a learning algorithm developed with the IBM Research organization, Easy Tier is designed to eliminate the complexity of manual data placement among tiers, while providing the value and flexibility of sub-volume or sub-LUN data placement. This supports improved performance/cost options. This is an improvement over traditional tiering methods that require manual intervention to move data between tiers, or that does not work at a granular level, requiring too much data to be moved to see any benefits. The IBM System Storage Easy Tier feature can determine the appropriate tier of storage based on data access requirements and then automatically move the data to the appropriate tier. This allows the manual effort involved to be reduced, if not eliminated. In this new dynamic environment, data movement is maintained to the host application regardless of the storage tier on which the data resides.

The IBM System Storage Easy Tier feature is designed to provide granularity in identifying and moving hot data at the sub-volume or sub-LUN (extent) level to SSDs. IBM System Storage Easy Tier requires the use of a hybrid extent pool which contains both SSD and HDD drives. Extents from HDDs can be moved dynamically within a hybrid pool to SSD drives. Data movement done by the DS8700 is dynamic and transparent to the host server and application use of the data. The Easy Tier algorithm will assign ‘heat’ values to each extent in a storage device. These heat values, hot or cold, will indicate what tier the data should reside on, and migration will take place automatically. Sub-volume or Sub-LUN data movement is extremely important compared to full volume movement as not all data at the volume/LUN level will be hot data. Since for any given workload there is a distribution of data considered ‘hot’ or ‘cold’; consequently, there is significant overhead associated with moving entire volumes between tiers. For example, if a volume is 1 TB, you would not have to move the entire 1 TB volume if the heat map generated indicates only 10 GB is considered hot. The DS8700’s extent size is 1 GB, requiring only 10 extents to move to optimize the workload in this example, versus 1,000 extents for a less tuned method. This capability makes improved use of the SSD technology’s higher performance while reducing the number of drives needed to improve that performance. In addition, depending on the workload and environment, it may be possible to combine Easy Tier, SSDs and larger capacity drives to receive equivalent or better performance than traditional high-performance configurations (using small spinning disks) while providing smaller footprints and lowering environmental costs.

Volume migration
Users can dynamically relocate logical volumes between extent pools or within an extent pool, or users can change the extent allocation algorithm (EAM) of a logical volume (for example, re-Rotate extents within the target extent pool), or users can merge two existing extent pools (combine existing extent pools with homogeneous disks; merge two extent pools with heterogeneous disks to use automated relocation; changes volume/rank to extent pool relationship without moving data).

Volume migration implementation:

• Migration is transparent to attached hosts
• Allows any supported volume to be queued for migration
• Actively migrates a number of extents per CEC concurrently
• Overheads comparable to FlashCopy with background copy

The DS8700 has been enhanced to include performance monitoring capabilities, regardless of whether you have installed and activated the Easy Tier license feature on your DS8700. The monitoring capability of the DS8700 enables it to monitor the usage of storage at the volume extent level. Monitoring statistics are gathered and analyzed every 24 hours. In an Easy Tier managed extent pool, the analysis is used to form an extent relocation plan for the extent pool, which provides a recommendation for relocating extents on a volume to the most appropriate storage device. The results of this data is summarized in a summary report from which you can download.

The DS8700 now offers a reporting tool called IBM System Storage DS8700 Storage Tier Advisor, hereafter referred to as advisor tool. The advisor tool is a Microsoft Windows application that provides a graphical representation of performance data that is collected by the Easy Tier over a 24-hour operational cycle. Volume performance statistics is included in a summary binary file that is transformed to a readable statistical report that you can download to a directory you specify on your Windows workstation from which you are accessing the DS8700. The advisor tool is the application that allows you to view the data when you point your browser to the file. (You can access the advisor tool with any standard Web browser.) You can view the information displayed by the advisor tool to analyze workload statistics, evaluate which logical volumes might be candidates for Easy Tier management. If you have not installed and enabled the Easy Tier feature, you can use the performance statistics gathered by the monitoring process to help you determine whether to use Easy Tier to enable potential performance improvements in your storage environment.

The value propositions
of IBM System Storage Easy Tier are:

• Manage storage performance within enterprise storage system to improve dynamic application demand or dynamic system configuration
• Improve performance/cost by taking advantage of the spectrum of storage drives available
• With a small percentage of data relocation from tier 1 or 2 to tier 0, a significant latency reduction or throughput improvement can be achieved for the total workload
• Moving small amounts of frequently accessed data to SSD can result in a better response time or increase in throughput, depending on customer workload and environment
• Enable customers to develop new insights into application workloads on their storage infrastructure and develop new optimization strategies

Eight drive install group of solid state disk (SSD)
Additional physical capacity for the DS8700 can be purchased via disk drive sets. A disk drive set contains 16 identical disk drives (same capacity and rpm). IBM System Storage DS8700 now offers the support of eight drive install group of SSD (half disk drive set), providing additional price/performance and capacity options to address specific application and business requirements. This support is in addition to the already supported 16 drive install group of SSD (a disk drive set). The 73 GB and 146 GB SSD half disk drive sets are supported.

600 GB 15,000 rpm disk drive
offers additional price/performance options
Physical capacity for the DS8700 is purchased via disk drive sets. A disk drive set contains 16 identical disk drives (same capacity and rpm). The DS8700 now offers 600 GB 15,000 rpm disk drive sets, providing additional price/performance options and capacity flexibility to address specific application and business requirements. This support is in addition to the already supported 73 GB (15,000 rpm), 146 GB (15,000 rpm), 300 GB (15,000 rpm), and 450 GB (15,000 rpm) Fibre Channel disk drive sets, 1 TB (7,200 rpm), and 2 TB (7,200 rpm) SATA disk drive sets, as well as intermix of 73 GB, 146 GB, 300 GB, 450 GB, and 1 TB disk drives. The 600 GB 15,000 rpm disk drives provide about 33% more raw capacity than 450 GB drives, increasing the total capacity of high-performance drives supported in a DS8700 system.

For additional flexibility, feature conversions are available for the 600 GB 15,000 rpm disk drive sets to exchange existing disk drive sets when purchasing new disk drive sets with higher capacity. The 600 GB 15,000 rpm disk drive sets are optional to the DS8700 and are available with feature numbers 27xx.

600 GB 15,000 rpm standby
capacity on demand (Standby CoD) disk drive sets
The IBM Standby CoD offering for the DS8700 allows inactive capacity to be installed and easily activated as business needs require. The DS8700 now offers the 600 GB 15,000 rpm disk drive sets as part of the Standby CoD offering. This offering provides up to four Standby CoD disk drive sets (64 disk drives) that can be factory or field installed into your system. The 600 GB 15,000 rpm Standby CoD drive sets are optional to the DS8700 and are available with feature numbers 27xx.

2 TB 7,200 rpm Serial ATA (SATA) drive sets
The DS8700 now offers 2 TB 7,200 rpm SATA disk drive sets, providing additional price and capacity flexibility to address specific application and business requirements. The 2 TB 7,200 rpm SATA disk drives can be added to the DS8700 models to support various fixed-content, data-archival, reference-data, and streaming applications that require large amounts of storage capacity at lower cost per MB. SATA drives are not intended for use in applications that require drive utilization duty cycles greater than 20%. In addition, SATA drives are supported only in RAID-6 and RAID-10 configurations. SATA drives will not share sparing capability with non-SATA drives, due to the low duty cycle nature of SATA drives.

The 2 TB 7,200 rpm SATA disk drives provide more raw capacity than existing models, up to 2,048 TB for DS8700 Model 941 (4-way) and up to 256 TB for DS8700 Model 941 (2-way). The 2 TB 7,200 rpm SATA disk drive sets are optional to the DS8700 and are available with feature numbers 29xx. 2 TB 7,200 rpm SATA drives will be available under the standard Capacity on Demand offering.

Quick initialization
IBM now supports quick initialization as an enhancement to device provisioning technology on DS8700 platforms. Quick initialization improves initialization speeds up to 2.6 times over previous versions of the DS8700 and allows a copy services relationship to be established after a device is created, while the provisioning of storage is in progress. These improvements can help allow users to create an enterprise storage environment, quickly provision new logical devices, and move the devices into production while utilizing the new Thin Provisioning technology in less time than ever before on DS8700 systems.

IBM System Storage DS8700 Thin Provisioning
The DS8700 now offers Thin Provisioning. Thin Provisioning allows users to overcommit storage to specific devices and throughout the system in general. This has several potential benefits. First, users can now allocate larger logical devices without having to provision the entire device. This allows users to consume storage allocated on the DS8700 without repeated device resizing as would be required today. The level of overcommitment can be decided by the user, but as the system consumes physical storage, administrators will be notified of physical allocations as it reaches user-specified limits. Once all of the physical storage is in use, no further virtual storage can be allocated, so action must be taken before this condition occurs.

Thinly provisioned devices can be increased in size as needed if the logical size of the device becomes constrained. If the physical storage approaches full allocation within a given extent pool, then users can add additional physical capacity (via drive sets) to increase the size of the extent pool.

Users may see a reduction in operating costs by being able to deploy fewer physical disks to provision a given set of logical devices that are underutilized. Thin provisioned devices offer performance that is comparable to standard, fully allocated, logical devices, and are effective in reducing capacity allocations. The ability to overconfigure logical device capacities may also help to reduce operational costs related to expanding storage allocations for host system software components such as logical volume managers, file systems, and databases.

For the initial release, the IBM System Storage DS8700 Thin Provisioning feature is available only for open systems, excluding System i. Support for IBM System Storage DS8700 Thin Provisioning is an optional feature of the DS8700 Model 941, and is available with the Thin Provisioning licensed feature indicator feature numbers 7071 and 0707 and corresponding DS8700 Function Authorization (239x-LFA) Thin Provisioning feature number 7071.

Remote Pair FlashCopy
The IBM DS8700 provides the Remote Pair FlashCopy with the capability to allow a FlashCopy (Point-in-Time copy) relationship where the FlashCopy target device is a Metro Mirror primary device. This can significantly reduces the recoverability time that exists when a FlashCopy background copy and Metro Mirror Resync are in progress. The Remote Pair FlashCopy provides a solution for data replication, data migration, remote copy, and disaster recovery tasks.

For business continuity, the Remote Pair FlashCopy operations are nondisruptive, allowing the primary device of each FlashCopy pair to remain available to all hosts for both read and write I/O operations. Once established, Remote Pair FlashCopy operations continue unattended to support continuous data backup to the secondary device.

z/OS support of Remote Pair FlashCopy is available on z/OS V1.9, or later, using the name FlashCopy Preserve Mirror.

Concurrent code load improvements
The current DS8700 code load process combines multiple phases of code load into one step. Because of this, code loads are perceived to be unnecessarily long. Splitting the phases into two allows for one phase (Distribution) to be done ahead of time without any loss of access or quiescing of any resource (no loss of redundancy). This would leave the other phase (Activation) to be much shorter and could be scheduled during off-peak periods. This will allow for a less than 2-hour activation phase of the main components of the DS8700. Once installed, this capability will be enabled when moving forward to future levels of code.

Prevent deletion of CKD and FB volumes in use
The DS8700 now supports additional measures to prevent online devices from deletion. ‘On-line’ devices have a specific meaning based on volume type. For CKD volumes, the volume is ‘on-line’ if it is participating in any Copy Services relationship, or if it is ‘grouped dynamic-pathing state’. FB volumes are ‘on-line’ if they are in a Copy Services relationship. The DSCLI will now always check for online status before completing a deletion command.

Disable recovery key
On a DS8700 only, if you have a security administrator, you can configure or disable a recovery key for the DS8000 storage facility image before an encryption group is created. You can disable a recovery key within a secure key environment. The state of the recovery key must be ‘Unconfigured’ in order to disable the recovery key. Be aware that if you disable a recovery key this allows an encryption group to be configured but with no recovery alternative. If, for some reason, you do not want a recovery key, you should disable it.

Encryption deadlock recovery key is to support the ability for customer administrators to restore access to a DS8700 when the encryption key for the storage is unavailable due to an encryption deadlock scenario. If customers disable the recovery key they do so at their own risk. Refer to White Paper IBM Encrypted Storage Overview V1.2 for best practices for prevention of the deadlock situation.

Rekey data keys of an encryption group
With security administrator access, users can rekey the data keys of their encryption group. With the encryption group rekey function, users can concurrently migrate a single platform key server configuration to a dual platform key server configuration to leverage changes in key management infrastructure. Both of these enhancements can help clients satisfy PCI (Payment Card Industry) security standards.

z/HPF extended distance
Reduces the impact associated with supported commands on current adapter hardware, thereby improving FICON throughput on the DS8700 I/O ports.