This article is reproduced in the EMC Chinese support forum. EMC released a new version of the VNX operating environment. The new version of the Block system is v05.32.000.5.006, and the new version of the File system is v7.1.47.5. The new version released this time has improved many functions and brought many surprising new features. This article will discuss the improvements and new functions of Fast VP and Storage Pool for Storage efficiency and performance.
Solution:
In the new version, Fast VP and storage pool mainly have the following improvements. This article will introduce in detail the new layering policy and the improvements in balancing.
· Support for hybrid RAID
· Add New RAID configurations
· Add a new Tiering policy
· Rebalance)
· Automatic load balancing at the level
Before introducing the design of the new version, we will first discuss the three layers of policies currently configured for FAST.
1) Highest available tier)
Suitable for applications with low access traffic but high access performance, such as OLTP requiring high performance. For LUNs with Highest available tier configured, their data Slice will be placed at the Highest available layer as much as possible. The LUN-1 is placed on the SSD block as shown in the figure.
2) Auto-tier)
Suitable for databases that require certain performance but are highly active. For LUNs configured with automatic layering, FAST will automatically allocate their data shards (Slice) between disks of different levels based on their activity levels ). As shown in the figure, the LUN-2 spans both the SAS and the NL-SAS.
3) Lowest available tier)
Suitable for applications with low performance and response time requirements, such as archive data. Regardless of its activity, FAST places the data Slice of these LUNs on the lowest available layer. As shown in the figure, the LUN-3 is placed on the NL-SAS disk.
New version introduces new FAST layering policy
Start High then Auto-tier)
When you select this policy for a given LUN, the initial data is allocated to the highest available layer, and then automatically layered based on the activity. As shown in the figure, the LUN-4 is initially all placed in the SSD block. Over time, some data has been cooled down and no longer requires SSD performance. Its data fragments will be moved from SSD blocks to SAS blocks.
Benefits of the new FAST layered strategy
The new policy enables the most expensive and fastest-performing hard disks to be put into use first, making full use of the disk to get the most cost-effective.
View new FAST policy with uniseries
Create a new LUN-> FAST configuration-> Policy Start High then Auto-tier
LUN properties-> FAST configuration-> policies Highest Available Tier and Auto-Tier
New balanced functions
1) Rebalance after storage pool resizing)
· During resizing, all data shards are reassigned across all disks.
· This function can be executed between different levels (Tier) and within the hierarchy
· This function is automatically triggered after a new disk is added. You do not need to install fast vp Enabler.
· Fast vp Enabler storage can be installed to manage this function (stop, pause, and continue)
2) automatically performs load balancing within the hierarchy
· Fast vp balances data between tiers, such as moving data from SAS to SSD or down to NL-SAS
· This function is based on data activity within the hierarchy and re-allocates data shards among different RAID groups (Slice)
· This function is automatically triggered after a new disk is added. You must install fast vp Enabler.
The example below will help us understand two new features.
As shown in the figure above, four + 1 RAID 5 SSD disks are used at the highest performance level of Hybrid Storage Pool 1, and four + 1 RAID 5 SAS disks are used at the performance level, select 6 + 2 RAID 6 NL-SAS as the capacity level. The two Pool LUNs in the hybrid storage Pool store hot, warm, and cold data. These LUNs are set to the Highest Available (Highest Available Tier ).
Please note that in this example, all SSD disks are full, and some hot data has to be stored at the performance level. In this case, 4 + 1 RAID 5 SSD disks are added to the storage pool. The system will automatically trigger the re-balancing mechanism, and the IO load will be balanced to all disks.
As shown in the figure above, after the rebalancing is triggered, the system will automatically try to balance the remaining data in the storage pool.
· Hot data on the SAS disk will be reassigned to the SSD disk.
· As the layered policy is set to the highest available, cold data on the SAS disk is also moved to the SSD disk.
· Data at the capacity level is moved to the SAS disk.
Benefits of new balancing functions
1) after resizing, rebalance the new disk to make full use of its space and performance.
2) server load balancer helps improve storage performance
Use unis to view the rebalance function
Storage pool Properties-> hierarchical state Tiering
· Move Down/Move Up the volume of data displayed to Move between different levels
· Move Within: displays the amount of data that is moved Within the hierarchy.
