pimax 8k

>linux Server installed the system, want to know whether the hard disk read and write to meet the needs of the service, if not meet the hard disk IO is a bottleneck of the service. So we need to test the hard disk read and write speed, testing a lot of methods, the following is the use of Linux with the DD command to test the read and write speed of the hard disk.Time has a timing function, DD is used for copying, read from If, write to of. If=/dev/zero does not produce IO, so it can be used to

needed to store each column. The driver also has the Fetchsize property, which is the number of rows returned per fetch. With the size and number of rows per column, the driver can calculate the maximum absolute length of the data returned by the fetch at a time. This is the size of the allocated buffer. Some large types, such as long and long RAW, are too large to be stored directly in the buffer to take another different approach. If the query result contains a long or long RAW, the memory pr

insufficient, maximum extension 5000MB ALTER DATABASE datafile ' D:\DataBase\Test.DBF ' autoextend on next 200m maxsize 5000m; --Extended infinite space alter DATABASE datafile ' D:\DataBase\Test.DBF ' autoextend on MaxSize Unlimited; Note Table space size limits Table space data file capacity and db_block_size, in the initial library, db_block_size to the actual needs, set to 4k,8k, 16K, 32K, 64K, and other sizes, Oracle's physical files only

various libraries and so shared modules that we use. You can use the PMAP directive to view detailed LIB libraries and used memory values for each process call. Take the simplest bash process here for example. [Root@91it ~]# pmap ' pgrep bash '1464:-bash0000000000400000 848K r-x--/bin/bash00000000006d3000 40K RW---/bin/bash00000000006dd000 20K rw---[anon]00000000008dc000 36K RW---/bin/bash00000000011a4000 396K rw---[anon]0000003ef9800000 128K r-x--/lib64/ld-2.12.so0000003ef9a1f000 4K R----/lib

The first thing to understand is two special devices: /dev/null: Recycle Bin, bottomless pit/dev/zero: Generating charactersØ Test Disk Write ability Time DD If=/dev/zero of=/test.dbf bs=8k count=300000 Because/dev//zero is a pseudo device that produces only a stream of empty characters and does not produce IO for it, IO is concentrated in the of file, and the of file is used only for writing, so this command is equivalent to the ability to write a

Oracle Single data file expands beyond 32GThe tablespace data file capacity is related to the Db_block_size setting, which is specified when the DB instance is created. The Db_block_size parameter can be set to 4K, 8K, 16K, 32K, 64K, and so on, Oracle's physical files only allow 4,194,304 blocks (this parameter is determined by the operating system, which is generally the number), The maximum value correspondence of a tablespace data file can be compu

IntroductionWeb development needs static files are: CSS, JS, fonts, pictures, can be accessed through the web framework, but the efficiency is not optimal. Nginx is much more efficient at working with static files than the WEB framework, because you can use the GZIP compression protocol to reduce the volume of static files to speed up static file loading, turn on caching, and time out to reduce the number of requests for static files. The following describes how to manage static file access th

limitations.Performing I/O in blocksTo improve I/O performance, PostgreSQL always performs I/O in blocks of 8k size. Therefore, you will see that your data files are always growing in 8k increments. When it comes to physical replication, you must make sure that both (master and slave) are compiled with the same block size.[Unless you explicitly compile PostgreSQL according to the different block sizes you

is currently exactly one packet that needs to be sent to the receiving end of the ACK acknowledgement, the ACK acknowledgement is attached to the packet and sent immediately. 3, when the timer expires, the ACK confirmation message is sent immediately. algorithm: 1, assuming Microsoft The TCP stack is spliced with packets that exceed the MTU value, and this data is sent immediately, without waiting for the previous data packet ack acknowledgement information. In Ethernet, the MTU

object by executing the engine.Based on the size of the object, the GC divides it into two categories: small objects (The GC free memory to the memory allocator is done through the memory allocation context. The size of the memory context has the allocation limit defined: The memory allocation context (Allocation contexts) is a smaller area on a thread-specific heap area (heap segment). On a single-processor (that is, a logical processor) machine, use the single context, which is the N

engine.Based on the size of the object, the GC divides it into two categories: small objects (The GC free memory to the memory allocator is done through the memory allocation context. The size of the memory context has the allocation limit defined: The memory allocation context (Allocation contexts) is a smaller area on a thread-specific heap area (heap segment). On a single-processor (that is, a logical processor) machine, use the single context, which is the No. 0 generation memory a

created for 8086/8088.In addition, the INTEL386 processor also supports: 32-bit address bus supporting up to 4G of physical memory Segmented (segmented) memory mode and flat (flat) memory mode Paging, 4k-sized pages provide a way to "virtual memory management" Support for parallel stages (should mean that the instruction executes several stages can be parallel) Clock frequency is 12.5MHzIntel?486 Processor (1989)The Intel486 processor enhances the execution of instruct

= $mcache->getallkeys (); Var_dump ($allKeys); Print_r ($mcache->getstats ()); * * In fact, from phpinfo () we can see that for the contents of more than 2000 bytes of content saved, memcached will turn on the compression For PHP arrays, Memcache is serialized, so the length of the saved content can be different from the actual content length. If you want to see the Memcache usage status on the server, you can use the Telnet 127.0.0.1 11211 command to view Get the actual stored value: Get str

To assess the development costs of this order system. To help a trading company make an order system, the basic module is: 1. Basic information of commodities. 2, the customer has been customer company basic information. 3. Basic information of employees. 4, quotation. 5, purchase orders. 6, delivery orders. All of the above documents require to be able to email to the customer, or export word, Excel, pdf format, and print, I would like to develop such a system now approximate price can be how

Original link: http://blog.csdn.net/maopig/article/details/6982457The system provides a socket buffer size of 8K, which you can set to 64K, especially when transferring live video.When the socket sends the data to the socket buffer, then accepts the function and then takes the data from the buffer, if the sender is very fast, the buffer is quickly filled (the socket default is 1024x8=8192 bytes), At this time we should set the buffer size according to

a test file under/var for testing use650) this.width=650; "class=" Exp-image-default "alt=" use/dev/zero and/dev/null to test HDD read/write Speed "src="/HTTP/ g.hiphotos.baidu.com/exp/w=500/sign=bf536fcaf503738dde4a0c22831ab073/ 622762d0f703918fa6be2da0523d269759eec468.jpg "/> Step reading 4Next, we write the infinite input in the/dev/zero to the test file via the DD command, and note that we use DD to make the timing with the time command.Time DD If=/dev/zero of=/var/test bs=

, unreasonable; on the one hand, the interrupt service program should deal with interrupts as soon as possible to ensure the IO throughput rate.-------------------------------Split Line----------------------------By reading the third edition of the Ulk Chinese version of page 164, let me have a clearer understanding of this issue:When the kernel is compiled with the value of thread_size set to 8K, then the kernel stack of each process is

have learned the basic use of buffer, next, we have to start doing buffer to do some testing. 3.1 8K's creation test Every time we create a new buffer instance, we check that the current buffer's memory pool is full, that the current memory pool is shared for the new buffer instance, and that the memory pool size is 8K. If the newly created buffer instance is greater than 8K, the buffer is given to the

The system provides a socket buffer size of 8K, which you can set to 64K, especially when streaming live video. When the socket sends data to send data to the socket buffer, then accept the function and then fetch the data from the buffer, if the sending end is very fast, the buffer will be filled up quickly (the socket default is 1024x8=8192 byte), At this point we should set the size of the buffer according to the situation, we can implement the #in

Come to the new company to do game development has been almost two years, the period encountered a variety of problems, make this record, so as not to repeat the same mistakes. 1: The game backstage uses the MySQL database, most game information uses the BLOB field to represent, adds the version number in the BLOB information, this can change the game information dynamically, but does not need to modify the data structure frequently. With the game to break development, more and more games, the