sas backplane

Backplane Air-Conditioning Technology in data centers In recent years, data centers have developed rapidly towards a large scale, integration, and high energy consumption. According to a survey, the power consumption of servers has increased by 15 times over the past decade. Currently, the power consumption of a single rack is between 20 and 20 ~ 30KW. Network equipment is also growing. Some large network equipment requires several talents to be able

such as the Cisco 2960x-24ps-l (24,000 Gigabit Port 4,000 gigabit), forwarding bandwidth 108Gbps, switching bandwidth 216Gbps, packet forwarding rate 71.4Mpps, according to the non-clogging line speed forwarding to calculate, exchange capacity of 2*28*1gbps=56gbps, The nominal 216Gbps is much higher than this, why? Is it due to the different design of the switch matrix? How did he figure out the 216Gbps? Again, for example: its packet forwarding rate is: 28*1.488mpps= 41.664mpps‘This problem has

backward-compatible with SATA. The back panel (backplane) of the SAS system can connect both a dual-port, high-performance SAS Drive and a high-capacity, Low-cost SATA Drive. Because the port of the SAS drive looks similar to the port shape of the SATA drive, SAS drives and

, SAS consists of three types of protocols, which are used for data transmission based on different connected devices. Serial SCSI protocol (SSP) is used to transmit SCSI commands; SCSI Management Protocol (SMP) is used to maintain and manage connected devices; SATA Channel Protocol (STP) it is used for data transmission between SAS and SATA. With these three protocols,

Disk back panel: Eclectic In the tower server where the rack server or the hard drive slot is higher, the SAS Hba/raid card is generally not connected to the hard drive directly with the SAS cable, but through the disk backplane to facilitate the hard drive Plug and unplug. Disk Backplane is also a typical internal co

cannot be used directly in SATA environments because SATA controllers do not control SAS drives;b). At the protocol level, SAS consists of 3 types of protocols, which are used to transmit data according to the different devices connected. Where the serial SCSI Protocol (SSP) is used to transport SCSI commands, SCSI Management Protocol (SMP) is used to maintain and manage connected devices, and SATA Channel

SAS interface technology can be backward-compatible with SATA. Specifically, the compatibility of the two is mainly embodied in the physical layer and the protocol layer compatibility. In the physical layer, the SAS interface and SATA interface are fully compatible, SATA hard disk can be directly used in the SAS environment, from the interface standard, SATA is a

interface, its electrical signal is defined by the interface specification, and the quantity depends on the design of the control chip (Controller IC, also including ROC). But the interface or port, all must rely on an entity's manifestation--mainly pin and connectors, can play the role of the connection, and then constitute the data path. As a result, there are interface connectors that are always used in pairs: on one side of the hard drive, HBA, RAID card, or

SAS Program has three types of errors: Programing logic errors (how to identify and resolve ); Syntax errors (how to recogize ANC correct ); Data errors (how to examine and resolve. How to write an efficient SAS Program: Write code that is easy to read as much as possible (one line per sentence, indented layout, and comments more) Test any part of the program Test Program with a small dataset (for

Path to mathematics-sas memo (10), path to mathematics-sas memo Merge combines two or more data sets. Libname saslib "k: \ sas "; DataSaslib. goodsprice; Input id name $ price6.2; Datalines; 1 mouse 35.6 2 Keyboard 28.95 3 mouse pad 8.2 4 headsets 29.7 ; DataSaslib. goodsquantity; Input id quantity; Datalines; 1 150 2 98 4 162 3 45 ; Proc sortData = saslib. goods

Opening remarks: I personally think that the entire SAS protocol family is large, and there are many concepts that are hard to understand. I can only study the actual code at work while reading the protocol in detail. In this way, we can better understand the SAS protocol. It is the best way to understand the protocol according to the code. Think about all the protocols for data transmission. The communicat

Path to mathematics-sas memo (18), path to sas memo 18Data _ null _;X = 15.63;Y = 15.13;Xx = ceil (x );Yy = ceil (y );Put xx = yy =;Xx = floor (x );Yy = floor (y );Put xx = yy =;Xx = int (x );Yy = int (y );Put xx = yy =;Xx = round (x, 0.1 );Yy = round (y, 0.1 );Put xx = yy =;Z = trunc (1/3, 3); * stores data in 3 bytes;Put z =;All content of this blog is original, if reproduced please indicate the source ht

Path to mathematics-sas memo (14), path to sas memo 14 Sas Date Format Data _ null _;X = '7jan2012 'd; Put x yymm7 .; Put x yymmc7 .; Put x yymmd7 .; Put x yymmn6 .; Put x yymmp 7 .; Put x yymms7 .; Put x yymon7 .; Put x mmddyy10 .; Put x yymmdd10 .; Run; All content of this blog is original, if reproduced please indicate the source http://blog.csdn.net/myhaspl

Path to mathematics-sas memo (17), path to mathematics-sas memo 17SAS Date and Time FormatData _ null _;Input mydate YYMMDD10 .;Put mydate YYMMDDB10 .;Put mydate YYMMDDC10 .;Put mydate YYMMDDD10 .;Put mydate YYMMDDN8 .;Put mydate YYMMDDP10 .;Put mydate YYMMDDS10 .;Cards;2014-05-;Run;All content of this blog is original, if reproduced please indicate the source http://blog.csdn.net/myhaspl/2014 05 182014-05-

recently re-spread on the database, the company's core database every day IO full, in the study with SAS 16*RAID10, or RAID10 ssd*6, or FIO;the principle, no raid-5 for database; eh; the root of all evil ;No.2 principle, most of the time, the database does not need too high CPU, now 2 sockets are basically enough, more MySQL is not used;No.3 principle, large memory, high IO, is the necessary condition of modern web-based database;now the big companies

In practical applications, we often convert wide data (one patient observation) into long data (one patient observation) or long data (one patient multiple observations) into wide data (one observation for a patient), and in R we can use the Reshape2 package. There are two implementations of the SAS: arrays and transpose. This blog post first explains the use of arrays to reconstruct SAS data, and the next

Path to mathematics-sas memo (13), path to sas memo 13Libname sastemp 'e:/sastemp /';Option user = sastemp; * specifies the reference name of the next logical database;Page; * The log starts from a new page;Data sales;Input id $ price;Skip 6; * Five blank lines are generated in the log;Cards;1 23.32 99.233 91.01;Proc print;Run;X 'dir. '; * execute the operating system command; all content in this blog is or

Path to mathematics-sas memo (9), path to mathematics-sas memo View Libname saslib "k: \ sas "; DataSaslib. testview4/view = saslib. testview4; Set saslib. test4; Run; Proc printData = saslib. test4 noobs label; Run; Proc SQL; Select testview4.id as student ID, testview4.score as score fromsaslib. testview4; Quit;All content of this blog is original, if reproduc

local hard drive for this blade. If there is a host or blade to the d2x00 on the dual path, if the d2x00 is a SAS hard drive, then the blade to the hard disk access between two paths is load balancing and failover. Http://h18000.www1.hp.com/products/quickspecs/13960_na/13960_na.html The p711m RAID card, a mezzanine card (mezzanine card, which can be understood as a single child), connects to the 6GB SAS BL

Path to mathematics-sas memo (6), path to mathematics-sas memo Connect external data Connect to database type options All content of this blog is original, if reproduced please indicate the source http://blog.csdn.net/myhaspl/ Connection ACCESS: Proc SQL; Connect to access as db (path = "e: \ xx. mdb "); Connect to excel: Proc SQL; Connect to EXCEL (PATH = "k: \ student_excel.xlsx" GETNAMES = YES