In our review of the Synology VMM hypervisor, we concluded that the company has discovered the way to the world of Hyper-converged storage, where a potential customer can use one device not only to access data, but also to run resource-intensive applications such as virtual desktops, databases and modeling systems and so on. Support for replication, snapshots and clustering allows you to build not just systems with reliability at the level of “five nines”, but very cheap systems with the highest reliability, where duplication of functions occurs at the level of the device itself, roughly speaking - the storage box itself.
Three Synology ideas distinguishing their storage from competitors
High Availability system-level redundancy. Ideology Synology has always been somewhat different than other manufacturers of storage systems and offering solutions for cloud-based systems, the company says: “you do not have to pay for duplication of all that are installed inside the one storage system - no need to duplicate the cables, controllers, host adapters, and so on. Our storage is affordable for any customer, and if you need maximum reliability, you just use the N+1 scheme at the level of the device itself. In any case, you save space in the data center, reduce the cost of electricity and network connections, but you achieve reliability at the expense of our software development, and not through the purchase of unused components, the only purpose of which is to maintain the system in rare cases of something out of order, because even load balancing can be done programmatically.” For experienced IT professionals, this approach seems strange, but only as long as you do not compare the cost of two or three top Synology solutions with a single “fully hardware” module from Dell/EMC or HPE.
Using iSCSI as the most promising interface. In 2015, the head of Mellanox, a leader in the production of host controllers and interconnects, said in an interview that the FC interface has no future. In his corporate blog Mellanox gives 7 reasons why Fibre Channel should be forgotten (in English) as a nightmare and move to iSCSI to work with block access.
The advantages of iSCSI are: the ability to use the storage at any distance from the client via TCP, and the speed of the interconnect, which today can be 200 GB / s per port, and a very low price of the host controllers and switches, and the ability to use the existing network infrastructure to work on iSCSI. Practically, choosing the iSCSI Protocol, the customer does not need to build a SAN network, no need to lay additional cables, inflating the budget to the heavens: a single network interface, single switch, single copper cable, which sends the traffic to the IPC, LAN and SAN, plus the ability to specify the priority of traffic at the host level.
Yes, three years after Mellanox sent Fibre Channel to the dustbin of history, this interface still remains in demand in the industry, mostly where there is already a SAN infrastructure, although there are already customers switching to iSCSI.
The use of software storage technologies. Today, storage is not so much hardware technology as software, and Synology says: "we do not have hardware RAID controllers, because the power of modern Intel Xeon processors is so high that the CPU is not something that copes with the calculation of XOR, but simply does not notice it. It is much more important to support direct transmission of iSCSI packets to save CPU resources not only of the storage itself, but also of the clients connected to it, so we have support for RDMA over Ethernet (see below). description of RDMA over Ethernet in English)."That is, it is much more important to provide fast data transfer outside than to take care of how it is arranged inside the storage, and you can not argue with this, although not every server today has support for RDMA over Ethernet.
Needless to say that Synology in their top-end storage system integrates all the technologies that have been acquired by it in the past. This file system btrfs with the function of snapshots, and built-in programs for remote replication, including Active Backup for Server, thanks to which the storage itself enters the server and copies data from it via RSync Protocol, and the possibility of replication between the storage via the Internet, so you can somewhere in a remote office to put a desktop NAS and on the weekends to do it off-site copies in encrypted form on an encrypted channel, or copy them to the cloud. And all this - without additional licenses, in a single web-interface, where you can work at least from your smartphone.