NVMe (Non-Volatile Memory Express) is a protocol for accessing SSD drives over the PCI Express bus. It is designed for high-speed data processing, which increases application performance. NVMe increases the performance of storage systems several times compared to current standards. Today it is mainly used in the Enterprise market.
The principle of operation
To work using the NVMe protocol, SSD drives are connected via the PCI Express bus, which allows the use of up to four parallel lines. The maximum data processing speed reaches 32 Gbit/s, which is 5 times faster compared to SATA.
The information is read directly, which increases the performance and response time of the software.
The first vendor to use this technology is NetApp. The company has been a leader in the storage market for a long time and, as a rule, is the first to introduce new developments into its solutions. A model range that uses NVMe technology — All-flash solutions (for example, AFF A250).
In 2020, Dell presented a completely new line of storage systems called PowerStore (for example, 3000T). It only works on NVMe SSD drives. The solution scales both horizontally and vertically.
Dell has implemented 2 storage options. With a traditional OS (the letter T is added at the end) and with a hypervisor (the letter X).
Huawei also did not stand aside and enabled NVMe protocol support on Dorado models (for example, Dorado 5000 V6). Storage systems also belong to the All-flash class and are supplied by the vendor for certain client tasks.
Lenovo has been working with NetApp for several years, so the storage model range is essentially OEM (Original Equipment Manufacturer — the original equipment manufacturer). ONTAP is used as an operating system on data storage systems, and there are also all the additional functions of the American partner, for example, DM 5000F.
Fujitsu has integrated the NVMe protocol into the AF storage line.
To work with the NVMe protocol, it is not enough to implement support only at the hardware level. Software development is also required. After the technology appeared, all vendors have updated their software to the latest versions and enabled protocol support.
Form factors
Since NVMe is a standard, it is used on various SSD form factors.
- PCI Express. It is used on both server and desktop platforms. It was used when the technology appeared as the only connection option.
- M.2. Mainly designed for laptops and workstations. A compact form factor that supports a maximum SSD length of up to 110 mm. Accepted M. standards2: 2230, 2242, 2260, 2280, 22110.
- U.2. The analogue of M.2, but is used in server solutions. It is compatible with server platforms according to mechanical parameters,
- EDSFF. It was developed by Intel mainly for its own solutions and SuperMicro platforms. It is an alternative to the U.2 form factor.
- NGSFF. Another alternative to U.2, developed by Samsung. It works with self-assembled solutions on Intel, Supermicro, etc. platforms. It has smaller dimensions compared to the previous form factor.
NVMe in SAN
The protocol is used not only in local servers, but also for building SAN storage networks. The standard is called NVMe-over-Fabrics.
In block-level information transfer protocols (for example, Fibre Channel), support for SCSI commands is replaced by NVMe. As a result, the delay does not exceed 10 ms.
The technology appeared in the middle of 2016 and is now actively developing in the Enterprise market.