xgimi 4k

of 20k, its basic storage unit is a cluster, with two files, a 7k, a 1k. When the cluster size is 4k, the disk is divided into 5 clusters, two files Occupy 3 clusters, that is, the use of 12k, which wasted space is 4k, that is, the creation of internal fragments 4k. So we know that internal fragmentation is primarily a waste of disk space. Note that the fragment

This experience is CentOSrelease6.7 (Final), such as the lack of knowledge welcome criticism.Knowledge about the Inode and block of Linux:1> Linux system partition format file system, the system will be divided into inode and block two parts:1) The inode is the system file's attribute information (the result of ls-l) and pointer to the file entity, but does not store the file name, usually in the upper directory block.2) block for storing data, EXT3/EXT4 General is 1k,2k,

Du = = Disk usage (disk usage, disk space occupied) ls = = = Apparent sizes (file length, file length field defined in the Files data structure) The amount of disk space a file occupies and the size of a file is a different situation. The footprint depends on the size of the file system block, Linux generally defaults to 4k (4096), so a file size of 1 bytes, the smallest to occupy 4k, if you create a filesy

transfer the large file.And there is a situation is if the small files are less than 4k, a file 4k,10000 is 40000k 40MAnd packaging, you will add less than 4k of files, so the average size of each file will be reduced, the total packaged data will be less than 40MTAR-CVF File/directory to be packaged after the file name is packagedc = CreateV indicates visualF i

1. Ls-lsh2. Du-sh Du = = Disk usage (disk usage, disk space occupied)The amount of disk space a file occupies and the size of a file is a different situation. The footprint depends on the size of the file system block (block), Linux is generally the default is 4k (4096), so a size of 1 bytes of files, the smallest also takes up 4k, if you create a file system when the block size is 16K, then even if a

, and the inode default size in the CENTOS6 series is 256 bytes.? In addition to storing the file's attribute information, the Inode also holds pointers to the data blocks that are executed? Block is used to hold the actual data, the common block size is 4K, its boot partition is 1 k, the other normal partition is 4K.? The inode does not contain a file name because the file name does not belong to the prope

;keepalive_timeout60;fastcgi_cache_path/usr/ local/nginx/fastcgi_cachelevels=1:2keys_zone=test:10minactive=5m;fastcgi_connect_timeout300; Fastcgi_send_timeout300;fastcgi_read_timeout300;fastcgi_buffer_size4k;fastcgi_buffers8 4k;fastcgi_busy_buffers_size8k;fastcgi_temp_file_wRite_size8k;fastcgi_cachetest;fastcgi_cache_valid2003021h;fastcgi_cache_valid 3011d;fastcgi_cache_validany1m;fastcgi_cache_min_uses1;fastcgi_cache_use_stale errortimeoutinvalid_hea

(for memory concepts):is usually a multiple of 64K.Spare: Not usedPrivate: BookedImages: Storing codeMapping: Storing data2. Physical memoryThe system can use the actual memory, the CPU can directly access the memory3. Virtual memoryVirtual memory data must be placed into physical memory when the CPU assumes access to virtual memory data by virtualizing the hard disk files into intrinsic use (Pagafile.sys).4. Memory page (for address concept)The smallest unit of system management memory. The me

); } ?> In addition, we also need to note that the refresh buffer is not only affected by the above aspects, but also by the following: 1) Some web server programs, especially the web server programs under Win32, will cache the Script output until the program ends before sending the results to the browser. Some Apache modules, such as mod_gzip, May output the cache by themselves, which causesFlush ()The results produced by the function are not immediately sent to the client browser. Even the b

does not display the entire table until the 2). The effect of PHP installation mode. The above method can be used directly in the case of PHP installed in Apache module mode. If you need to pay attention to the following configuration in the fastcgi way: a). apache+fcgid+phpFcgidoutputbuffersize 0 (default is 65536) When you configure Fcgid, this value is set to 0, and the above code does the refresh buffer to achieve its desired effect. b). iis+fastcgi+php Responsebufferlimit=0 Modify this it

for hard disks: MBR and GUID (GPT)MBR: Master boot record, supports up to 4 primary partitions, identifies up to 4G of single hard DrivesFile system formats: NTFS and FAT32Hard Drive 4K Alignment:A file 1K also takes up 4K of space.NTFS format is 4K is a cluster, the original hard disk sector is 512 bytes, in order to align the NTFS cluster, the hard disk format

operating system provides a virtual process space for each process, on a 32-bit operating system, the size of the process space is 4g,64-bit system 2^64 (which may actually be less than this value). For a long time, I was very puzzled about this, so that does not lead to multiple processes to visit the conflict, for example, two processes are access to address 0x00000010. In fact, the process space for each process is virtual, which is not the same as the physical address. The two are accessing

this, but also achieved a very successful effect.Author Antirez Several reasons for explaining why to implement the VM himself (6). The main OS VM swap out is based on the page concept, such as OS VM1 page is 4K, 4K as long as there is an element even if only 1 bytes are accessed, the page will not be swap, the same reason, read a byte may be swapped into 4K of

The most common physical unit on a disk is a sector, and a disk consists of a number of sectors.The sector size of an older disk is 512 bytes.CHS and LBA are two ways of addressing a disk and are now used in LBA mode.The LBA method is simple, and all sectors are numbered starting at 0, and the location of the sector is specified by the number of mountains.With Fdisk-lu, you can see the number of slices of a disk and its partitions.Sector number NO. 0 is the sector that stores the MBR.In MBR 0-44

time.Reset_timedout_connection on; #告诉nginx关闭不响应的客户端连接. This will release the memory space occupied by that client.Send_timeout 10; #指定客户端的响应超时时间. This setting is not used for the entire forwarder, but between two client read operations. If, during this time, the client does not read any data, Nginx closes the connection.AutoIndex on; #开启目录列表访问, the appropriate download server, the default shutdown. Client_header_buffer_size 32k; #客户端请求头部的缓冲区大小, this can be set according to your system paging s

CI nginx Rewrite rules server {Listen 80;server_name ttlsa.com www.ttlsa.com;root/data/site/www.ttlsa.com;Index index.php;Error_log Log/error.log;# Set expiration of assets to MAX for cachingLocation ~*. (ico|css|js|gif|jpe?g|png) (? [0-9]+)? $ {Expires Max;Log_not_found off;}# main CodeIgniter rewrite ruleLocation/{Try_files $uri $uri//index.php;}# PHP parsingLocation ~. php$ {root/data/site/ttlsa.com/;Try_files $uri = 404;Fastcgi_pass Unix:/tmp/php5-fpm.sock; # changed to the corresponding fas

=" consider using RAID 50 to replace raid ten (SSD) "style=" Border:0px;vertical-align:middle;height:auto; />RAID 50 in the above comparison has been able to tolerate the 3rd or even 4th disk failure, but the availability is lower than raid 10, but neither of them can achieve the perfect 100%, so the tradeoff between availability and cost of RAID 50 is a considerable advantage.Next look at performance, in order to be able to analyze performance well, we followed the first set of comparison scena

Recent program error: Failed to connect to Redis:connection timed outFind information about THP, decide to test and modify1.page and Huge PagesPageIn general, memory management of the minimum block-level units called page, a page is 4096bytes,1m memory will have 256 PAGE,1GB words will have 256,000 page.The CPU maintains the page table record through the built-in memory management unit.Huge Pages:Huge pages is a 2M to 1GB memory page, mainly used to manage thousands of trillion of memory, such a

1 2 4 8 Ten - - + +; DoSysbench--test=fileio--file-TOTAL-SIZE=256G--file-test-mode= $rwtype--max- Time= ---max-requests=0--file-BLOCK-SIZE=4K--file-num= ---num-threads= $numthread run >> $result _dir/Io_${rwtype}_thread${numthread}.txt; Sleep Ten; Done Done#-----------------------------CPU Test-------------------------------- foreachinch 1`seq 2 2 +`; DoSysbench--test=cpu--cpu-max-prime=40000--num-threads= $each run >> $result _dir/Cpu_thread

/error.log; #gzip compressed transport gzip on; Gzip_min_length 1k; #最小1K gzip_buffers 64K; Gzip_http_version 1.1; Gzip_comp_level 6; Gzip_types text/plain application/x-javascript text/css application/xml application/javascript; Gzip_vary on; #负载均衡组 #静态服务器组 upstream static.zh-jieli.com {server 127.0.0.1:808 weight=1;} #动态服务器组 upstream zh-jieli.com {server 127. 0.0.1:8080; #server 192.168.8.203:8080; } #配置代理参数 proxy_redirect off; Proxy_set_header Host $host; Proxy_set_header X-real-ip $remote _a