Enterprise Virtual Array
The HP StorageWorks Enterprise Virtual Array , EVA for short, appeared in 2001. The system was developed by DEC, taken over by Compaq and integrated into the product range in the course of the takeover by Hewlett-Packard in 2002.
EVA generations
The product range is divided into various Enterprise Virtual Array models.
| model | Controller |
|---|---|
| EVA3000 | HSV100 |
| EVA5000 | HSV110 |
| EVA4000 | HSV200A |
| EVA4100 | HSV200B |
| EVA4400 | HSV300 |
| EVA6000 | HSV200A |
| EVA6100 | HSV200B |
| EVA6400 | HSV400 |
| EVA8000 | HSV210A |
| EVA8100 | HSV210B |
| EVA8400 | HSV450 |
| EVA-P6300 | HSV340 (2011) |
| EVA-P6500 | HSV360 (2011) |
There are currently five models available, the EVA6400 and EVA8400 being the latest in a new generation.
| model | Controller |
|---|---|
| EVA4400 | HSV300 |
| EVA6300 | HSV340 |
| EVA6400 | HSV400 |
| EVA8400 / 14 GB cache | HSV450 |
| EVA8400 / 22 GB cache | HSV450 |
technical structure
All EVA systems work from the hard drive to the host port with fiber channel , partly via copper cables, partly via fiber optics . The disk shelves and hard disks are connected to the controller pair via two redundant (EVA6400 two FC loops and EVA8400 three FC loops) FC-AL connections. Each controller (two controllers per EVA) has two or four host ports with which the controllers are connected to the fabric. With the entry-level systems, EVA4x00, the disk shelves are connected directly to the controller. The disk shelves are also connected redundantly here. With the models 5000, 6x00 and 8x00 loop switches are used (with EVA4400, 6400 and 8400 this task is taken over by so-called "switched IO modules", they have no switches). These loop switches break up the physically existing ring structure into a physical star structure , which is logically still a ring. With the use of loop switches, entire disk shelves can even be added during operation. Theoretically, this is also possible with an EVA4x00, but HP advises against it. The entire backend, i.e. the connection of the hard disks to the disk shelves and the connection of the disk shelves to the controller, works with 2 GB FC. The EVA4400 changes this state and works with 4 GB FC from the hard disk to the host port. The claim that 2 GB FC is a bottleneck has not yet been proven. An EVA8100 achieves up to 210,000 IOPS and 1500 MB / s. An EVA can manage between 8 and 240 hard drives. Hard disks are available with FC and FATA interfaces. FATA hard disks are ATA hard disks with a Fiber Channel interface. This allows you to mix FATA and FC disks in one disk shelf, a great advantage over many other manufacturers in this area. This is also possible with systems that use SAS and SATA hard disks. Different hard drives are currently available:
| size | speed | interface | comment |
|---|---|---|---|
| 300 GB | 10,000 rpm | Fiber Channel | 2 Gb FC, all EVA models except EVAx400 |
| 146 GB | 15,000 rpm | Fiber Channel | 2 Gb FC, all EVA models except EVAx400 |
| 300 GB | 15,000 rpm | Fiber Channel | 2 Gb FC, all EVA models except EVAx400 |
| 450 GB | 15,000 rpm | Fiber Channel | 2 Gb FC, all EVA models except EVAx400 |
| 1 TB | 7200 rpm | Fiber Channel | F-ATA disk |
| 72 GB | SolidStateDisk | Fiber Channel | 4 Gb, EVAx400 only |
| 200 GB | SolidStateDisk | Fiber Channel | 4 Gb, EVAx400 only |
| 400 GB | SolidStateDisk | Fiber Channel | 4 Gb, EVAx400 only |
| 300 GB | 10,000 rpm | Fiber Channel | 4 Gb, EVAx400 only |
| 450 GB | 10,000 rpm | Fiber Channel | 4 Gb, EVAx400 only |
| 600 GB | 10,000 rpm | Fiber Channel | 4 Gb, EVAx400 only |
| 146 GB | 15,000 rpm | Fiber Channel | 4 Gb, EVAx400 only |
| 300 GB | 15,000 rpm | Fiber Channel | 4 Gb, EVAx400 only |
| 450 GB | 15,000 rpm | Fiber Channel | 4 Gb, EVAx400 only |
| 600 GB | 15,000 rpm | Fiber Channel | 4 Gb, EVAx400 only |
| 1 TB | 7,200 rpm | Fiber Channel | F-ATA, EVAx400 only |
| 2 TB | 7,200 rpm | Fiber Channel | F-ATA, EVAx400 only |
| 300 GB | 15,000 rpm | SAS 3.5 " | 6G, only EVA P6x00 |
| 450 GB | 15,000 rpm | SAS 3.5 " | 6G, only EVA P6x00 |
| 600 GB | 15,000 rpm | SAS 3.5 " | 6G, only EVA P6x00 |
| 2 TB | 7,200 rpm | SAS 3.5 " | 6G, only EVA P6x00 |
| 146 GB | 15,000 rpm | SAS 2.5 " | 6G, only EVA P6x00 |
| 300 GB | 10,000 rpm | SAS 2.5 " | 6G, only EVA P6x00 |
| 450 GB | 10,000 rpm | SAS 2.5 " | 6G, only EVA P6x00 |
| 600 GB | 10,000 rpm | SAS 2.5 " | 6G, only EVA P6x00 |
| 500 GB | 7,200 rpm | SAS 2.5 " | 6G, only EVA P6x00 |
The controllers are each housed in their own 2U high controller shelf. These two controller shelves therefore require 4U in one rack . The P4400 and P6xx0 series also have controller shelves with both controllers and an additional management controller in a 2U housing. The controllers are redundantly connected to one another via mirror ports. Depending on the controller, the controller pair has a cache of 4 to 8 GB. The controllers work with PowerPC CPUs and with XCS (name of the firmware) based controllers always work in an active / active network. Older EVA3000 and 5000 systems with VCS 4.x (name of the firmware) are able to work in a restricted active / active network.
Memory management
The storage in an EVA system is fully virtualized. While classic storage systems work with RAID sets and logical drives , an EVA works with disk groups and Vdisks. Instead of connecting hard disks to RAID sets with a certain RAID level in the classic case and then creating logical drives from them, hard disks are organized in disk groups at an EVA. At least eight hard drives of the same size and speed are required to form a disk group. Therefore the smallest EVA system always consists of a so-called 2C1D 8 HDD configuration: 2 controllers, 1 disk shelf and 8 hard disks.
Protection level
All hard disks are always active within a disk group. There are no savings discs. Instead of using spare disks, enough space is kept free across all hard disks in a disk group so that the largest hard disk in the disk group can be restored there. By not using spare disks, no IOPS are lost due to inactive hard disks. This freeing up of storage space is known as the protection level . There are three levels to choose from: None, Single and Double . When ProtectionLevel None no memory is allocated. With Single , double the capacity of the largest hard disk in the disk group is reserved, with Double, four times the capacity. Thus, the EVA can cushion the failure of one or two hard drives. The double capacity is due to technical reasons, since the EVA connects all hard drives internally in pairs. If a disk fails, the data on the failed disk and its partner, the so-called Widow , are restored to the free space. As long as there is free space in a disk group, the controllers restore the hard disks to the free disk space. If this is insufficient, the reserved space is used.
RAID level
All EVA systems are capable of RAID levels VRAID 0, VRAID 1 and VRAID 5. A Vdisk, i.e. a logical drive that can be presented to a host, always extends over all hard disks in a disk group. Has a disk group, e.g. If, for example, there are 56 hard disks and a 1 GB Vdisk is created, this 1 GB Vdisk is distributed over all 56 hard disks. This Vdisk is correspondingly powerful. Vdisks with different RAID levels can easily be mixed within a disk group. This is also not possible with all systems from competitors. HP strongly advises against mixing different disk sizes and technologies within a disk group. It is recognized best practice to create as few disk groups as possible, each with as many disks as possible. From this one can conclude that it makes more sense to use 32x 72 GB hard drives instead of 16x 146 GB hard drives.
It is quite possible that a productive Vdisk is operated in a VRAID 1, but a clone for tests with VRAID 5.
Internal administration
Internally, the controllers assign all hard drives to a redundant storage set , or RSS for short. These RSS have 6 to 11 hard drives. In an EVA system with 16 hard drives, there are two RSSs. Each RSS is a single RAID Protection Domain . The EVA uses e.g. B. for VRAID 1 a 4D + 4P, for VRAID 5 a 4D + 1P mechanism. Four datachunks are stored on four different disks in an RSS, as is one paritychunk. It is comparable with VRAID 1. A hard disk can therefore contain different data and parity chunks. If a hard drive fails, only one RSS is affected. Now it becomes clear why the EVA binds hard disks in pairs: These pairs always form a 1D + 1P part of a VRAID 1. If a disk fails, the data is restored to the free area and mirrored again there. The data are mirrored again after the restore. Depending on the RSS status, which can be None , Mirrored or Parity , even a whole disk shelf failure can be intercepted. The EVA controllers always ensure an optimal distribution of plates. If z. If, for example, there are eight disk shelves and 64 hard disks, the EVA will try to create several RSSs with eight hard disks each, with one RSS extending vertically over all eight disk shelves. To protect the metadata, they are located at the beginning of a disk group and are distributed over several disks. Up to five copies are kept.
software
The system is administered using software called HP StorageWorks Command View EVA software. This software is installed on a management server. This server is only necessary for administration. If it fails, the system continues to run as usual, only administration is no longer possible. With a Command View EVA installations up to 16 EVA systems can be managed. It is planned to move management to an embedded Command View server in the next generations. The EVA4400 is already prepared for here.
HP StorageWorks Business Copy EVA can create snapshots, clones, snapclones and mirror clones. So you can z. B. simplify data backups, or very simply generate test data and prepare migrations. Online raid migration will also be possible in 2011.
If necessary, EVA systems can be mirrored via HP StorageWorks Continuous Access EVA. Mirroring is possible synchronously or asynchronously.
HP StorageWorks EVA Dynamic Capacity Management Software simplifies the management of storage space and helps to better utilize a storage system. With this product u. a. Thin provisioning possible.
The long-awaited “real” thin provisioning was added in summer 2011.
HP StorageWorks Secure Path for HP-UX and multi-path failover software ensure optimized path management if the operating system cannot handle redundant paths by default.
Others
Vdisks can be exported via iSCSI using the EVA iSCSI Connectivity Option . An iSCSI-to-FC bridge is integrated into the EVA, which can be administered via the Command View EVA. This makes it possible to provide high-performance storage at low cost via iSCSI. For larger file server environments there is EVA File Services, which is a solution consisting of EVA storage systems, ProLiant servers and HP PolyServe File Serving. A network of ProLiant servers, operated with Windows or Linux, works as a virtual file server. The file server can be addressed via CIFS , NFS or Polyserve Direct I / O. The IP Distance Gateway is used to mirror two EVA systems over longer distances. This means that larger distances can also be bridged with inexpensive IP routes.
A total of around 200 petabytes are currently installed in the form of EVA storage systems.
Individual evidence
- ↑ HP StorageWorks EVA 4000, 6000, 8000 - Fiber Channel Drive Enclosures, Identifying. Retrieved July 7, 2020 .