said a few words, and many people in the background left messages to consult questions. Most of them were OLT, BARS, NATh types and other issues that I had talked about before. These issues have been nagged in very detailed and tediously in the previous few issues. If you haven't read it yet, the link will be placed at the end of this article.
For the purpose of purchasing servers to run PCDN projects, the general recommendation is as follows:
single IP ≤50Mbps, it is recommended to use small machines with RAM architecture (such as Wanke Cloud, JD router, Octopus Planet, etc.).
Single IP ≤100Mbps and total bandwidth ≤2Gbps can be considered for using assembled servers, such as South China and Ultramicro motherboards.
Single IP ≥50Mbps and medium bandwidth ≥3Gbps can be considered using brand second-hand servers, such as Dell , Huawei , etc.
This article mainly takes Dell's second-hand server as an example, and talks in detail about the precautions of procurement systems and accessories.
First, determine the requirements before purchasing. Before determining the requirements, you must first determine your total bandwidth and the docking platform. Most of the servers of
- U have 8 hard disks, and the vast majority of models cannot expand the disk, that is, the maximum data disk is 7. Only supports 2.5-inch hard drives. It is cheap, has a small space and low noise, and is currently mainstream.
1. Barbecue system: Recommended dell R620/R630 R720/R730 or Huawei 1288/2288
barbecue system includes: shell, motherboard, heatsink, array card, network card , power supply and remote control module.
- case, motherboard, and heatsink have been configured by default, and there is no choice. Some models of servers can replace mute/brute force fans.
- array card: PCDN only needs to configure RAID0 array card mode.
- power supply: It is recommended to purchase the maximum power supply.
- dell commonly uses H310 and H710.
H310 continuous read and write speed is about 10-20MB/S. There is no controller cache during design, which is basically the edge of elimination. Unless you do direct, you will lose the advantage of superimposing speed of the hard disk. Very cheap.
H710 continuous read and write speed basically has no bottlenecks, with a maximum cache of 1GB. The operation steps of
array card RAID0 and pass through will be described in the next issue. The screenshots and introductions will be given in detail in the server.
2. CPU: Purchase according to the number of bandwidth. In the absence of soft routing, one thread generally corresponds to one dial.
, such as E5-2697V2 2.7G, 12 cores and 24 threads, the maximum number of dials in the case of dual CPUs is 48. For detailed parameters, see the figure below:
V2 partial CPU thread: core number *2
V3 partial CPU thread: core *2
R620/R720/2288V3/1288V2 Purchase the CPU of V2. R630/R730/1288V3/2288V3 choose V3 CPU. Just purchase according to actual needs.
3. Memory: server memory is different from desktop memory, and the two cannot be mixed. The server memory has the ECCh flag.
ECC (Error Correcting Code): A technology that can achieve "Error Checking and Correcting". ECC memory is memory that applies this technology. It is generally used on servers and graphics workstations, which can improve the stability of computer operation and increase reliability. The higher the frequency of
, the more bandwidth utilization it can ensure. It is recommended to purchase the highest frequency.
memory capacity actually refers to the hardware requirements of each platform, and it is recommended that it should not be less than 128G. The location of the
memory slot is generally marked on the motherboard and the heat sink. Insert memory according to the identifier, otherwise one of them will not work or the load will be unbalanced. As shown in the figure below:
A1=CPU1 B1=CPU2
4. Network card:
has its own 2/4-port Gigabit electric network card by default. According to the configuration requirements of each person's switch , replace the default network card or add an additional network card in the PCIE slot. Some merchants can replace the 4-port Gigabit electric port network card for free with 2-port Gigabit electric port 2-port 10 Gigabit electric port, but the compatibility is very poor and they are very picky about the optical mode integrated cable. The programs of some platforms cannot recognize or only recognize two of them. Some platforms can solve the problem by connecting to a gigabit and 10 Gigabit network before installation.
5. Hard disk:
All hard disks are recommended to purchase enterprise-level solid-state drives . Some servers do not recognize consumer-grade (ordinary) solid-state drives, which may even cause errors and damage to the hard disk backplane. The most critical hardware for PCDN's revenue lies in the hard disk. Once there is a problem with the hard disk, the revenue will be greatly reduced. Do not lose the big one because of small amounts. It is better to increase the hard disk investment in the early stage.
Brand recommendations: Inter, Samsung , Magnesium .
interface mode: U2, SATA (SAS), M2. After testing, M2 has the worst effect in server PCIE, and the M2 slot specially provided in the middle of the server can only be used as a system disk. Some U2 models (such as R630) provide direct interfaces, and most models need to purchase a dedicated conversion card and plug it into PCIE. SAS is one of the interfaces of mechanical hard disk .
- system disk:
system disk is recommended to purchase an enterprise-level solid-state drive, which not only greatly improves the boot speed, but also plays an irreplaceable role in the response to instructions, the linking of local data and the operation of the system. The capacity is generally not more than 300G due to the requirements of each platform. It is recommended to purchase 360G-480G and the most cost-effective.
- data disk:
data disk is recommended to use U2 large-capacity solid state, focusing on the following parameters:
- continuous read and write IPOS (Input/Output Operations Per Second) is a measurement method used for performance testing of computer storage devices (such as hard disk (HDD), solid-state drive (SSD) or storage area network (SAN)). It can be regarded as the number of reads and writes per second.
- . Command delay, that is, how long does it take for each command to complete; the enterprise level will require this parameter to be 12us, while the consumer level will not require it, as long as the average IOPS of the speed test tool will be 10K.
- Lifespan: The theoretical total number of erases for eTLC flash memory is 10,000 times, while the consumer-grade cTLC is only 3,000 times. Other granular girls have them, and I won't list them one by one. Although enterprise-level NAND particles are already TLC, their maximum PE times are far higher than consumer products. Continuously polish the GC algorithm and wear balance algorithm, optimize the writing efficiency and reduce write amplification, reduce actual nullification of NAND, and further ensure life. In addition, the data accuracy is guaranteed, and NAND can also be avoided from being hung up in advance. A large amount of OP space is reserved, whether it is used for Block replacement, buffering for write amplification, or establishment of simulated SLC, which is of great help.
- Capacity: Depends on the total bandwidth of the access server. Most PCDN directional tasks require 1Gbps for 1.6--2T hard drives, and some platforms require 2T or above.
- Mechanical disk: On the verge of elimination, most platforms clearly state that mechanical hard disk cannot be used, or prompt that the hard disk performance is insufficient, and the profit is greatly discounted. Currently, only some network disks and iQiyi's large nodes accept mechanical hard drives, and the returns are also very low.
6. Remote control
comes with default, and the relevant settings will be explained in the next issue of the picture.
7. Server hardware monitoring and management (noise control)
comes with default, and the relevant settings will be explained in the next issue of the picture.
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