# sysio **Repository Path**: dropInTheBucket/sysio ## Basic Information - **Project Name**: sysio - **Description**: No description available - **Primary Language**: Unknown - **License**: Not specified - **Default Branch**: master - **Homepage**: None - **GVP Project**: No ## Statistics - **Stars**: 0 - **Forks**: 0 - **Created**: 2024-01-18 - **Last Updated**: 2024-01-18 ## Categories & Tags **Categories**: Uncategorized **Tags**: None ## README 关于操作系统IO篇章 冯诺依曼体系结构：计算器，控制器，主存储器，输入设备，输出设备 ``` 常用软件： yum install -y strace lsof pmap tcpdump ``` ``` VFS: 虚拟文件系统 案例 [root@node01 ~]# df Filesystem 1K-blocks Used Available Use% Mounted on /dev/sda3 202092480 10776508 181050220 6% / tmpfs 1954400 0 1954400 0% /dev/shm /dev/sda1 198337 27795 160302 15% /boot df Filesystem 1K-blocks Used Available Use% Mounted on /dev/sda3 202092480 7187520 184639208 4% / tmpfs 1954400 0 1954400 0% /dev/shm /dev/sda1 198337 27795 160302 15% /boot 通过自己创建磁盘镜像文件，挂载到vfs目录中，进行目录文件操作： dd if=/dev/zero of=~/disk02.img bs=1048576 count=100 losetup /dev/loop0 ~/disk02.img mke2fs /dev/loop0 mkdir /mnt/ooxx mount -t ext2 /dev/loop0 /mnt/ooxx cd /mnt/ooxx mkdir bin lib64 whereis bash ldd /bin/bash cp /bin/bash bin cp /lib64/{libtinfo.so.5,libdl.so.2,libc.so.6,ld-linux-x86-64.so.2} lib64 chroot ./ echo "aaa" > /abc.txt exit cat abc.txt ``` ``` 【抽时间一定要去实操，光看不够的】 测试pipeline类型： { echo $BASHPID ; read x; } | { cat ; echo $BASHPID ; read y; } 测试socket类型： exec 8<> /dev/tcp/www.baidu.com/80 lsof -op $$ 【以下是整合的结果】 COMMAND PID USER FD TYPE DEVICE OFFSET NODE NAME bash 4398 root cwd DIR 8,3 10227872 /root/mashibing bash 4398 root rtd DIR 8,3 2 / bash 4398 root txt REG 8,3 7077890 /bin/bash bash 4398 root mem REG 8,3 1572903 /lib64/libresolv-2.12.so bash 4398 root mem REG 8,3 1572891 /lib64/libnss_dns-2.12.so bash 4398 root mem REG 8,3 1709499 /usr/lib/locale/locale-archive bash 4398 root mem REG 8,3 1572893 /lib64/libnss_files-2.12.so bash 4398 root mem REG 8,3 1572877 /lib64/libc-2.12.so bash 4398 root mem REG 8,3 1572883 /lib64/libdl-2.12.so bash 4398 root mem REG 8,3 1572920 /lib64/libtinfo.so.5.7 bash 4398 root mem REG 8,3 1572867 /lib64/ld-2.12.so bash 4398 root mem REG 8,3 1968395 /usr/lib64/gconv/gconv-modules.cache bash 4398 root "0u CHR 136,2 0t0 5 /dev/pts/2" bash 4398 root 1u CHR 136,2 0t0 5 /dev/pts/2 bash 4513 root "0r FIFO 0,8 0t0 39968 pipe" bash 4398 root 2u CHR 136,2 0t0 5 /dev/pts/2 bash 4398 root "6r REG 8,3 0t0 10227564 /root/ooxx.txt" bash 4398 root "8u IPv4 39172 0t0 TCP node01:54723->104.193.88.123:http (CLOSE_WAIT)"" bash 4398 root 255u CHR 136,2 0t0 5 /dev/pts/2 read a <& 6 通过读取6号文件描述符，查看0t4的offset变化 一切皆文件：这里主要展示 socket/pipeline 另外，fd，文件描述符代表打开的文件，有inode号和seek偏移指针的概念 ``` ``` -Djava.nio.channels.spi.SelectorProvider=sun.nio.ch.EPollSelectorProvider strace -ff -o out java -Djava.nio.channels.spi.SelectorProvider=sun.nio.ch.PollSelectorProvider -cp /root/netty-all- 4.1.48.Final.jar:. NettyIO ``` ``` vm.dirty_background_ratio = 0 vm.dirty_background_bytes = 1048576 vm.dirty_ratio = 0 vm.dirty_bytes = 1048576 vm.dirty_writeback_centisecs = 5000 vm.dirty_expire_centisecs = 30000 ``` ``` cp pcstat /bin ``` ``` net.ipv4.tcp_timestamps = 1 net.ipv4.tcp_window_scaling = 1 net.ipv4.tcp_sack = 1 net.ipv4.tcp_retrans_collapse = 1 net.ipv4.tcp_syn_retries = 5 net.ipv4.tcp_synack_retries = 5 net.ipv4.tcp_max_orphans = 262144 net.ipv4.tcp_max_tw_buckets = 262144 net.ipv4.tcp_keepalive_time = 1 net.ipv4.tcp_keepalive_probes = 9 net.ipv4.tcp_keepalive_intvl = 75 net.ipv4.tcp_retries1 = 3 net.ipv4.tcp_retries2 = 15 net.ipv4.tcp_fin_timeout = 60 net.ipv4.tcp_syncookies = 1 net.ipv4.tcp_tw_recycle = 0 net.ipv4.tcp_abort_on_overflow = 0 net.ipv4.tcp_stdurg = 0 net.ipv4.tcp_rfc1337 = 0 net.ipv4.tcp_max_syn_backlog = 2048 net.ipv4.tcp_orphan_retries = 0 net.ipv4.tcp_fack = 1 net.ipv4.tcp_reordering = 3 net.ipv4.tcp_ecn = 2 net.ipv4.tcp_dsack = 1 net.ipv4.tcp_mem = 364704 486272 729408 net.ipv4.tcp_wmem = 4096 16384 4194304 net.ipv4.tcp_rmem = 4096 87380 4194304 net.ipv4.tcp_app_win = 31 net.ipv4.tcp_adv_win_scale = 2 net.ipv4.tcp_tw_reuse = 0 net.ipv4.tcp_frto = 2 net.ipv4.tcp_frto_response = 0 net.ipv4.tcp_low_latency = 0 net.ipv4.tcp_no_metrics_save = 0 net.ipv4.tcp_moderate_rcvbuf = 1 net.ipv4.tcp_tso_win_divisor = 3 net.ipv4.tcp_congestion_control = cubic net.ipv4.tcp_abc = 0 net.ipv4.tcp_mtu_probing = 0 net.ipv4.tcp_base_mss = 512 net.ipv4.tcp_workaround_signed_windows = 0 net.ipv4.tcp_challenge_ack_limit = 100 net.ipv4.tcp_limit_output_bytes = 131072 net.ipv4.tcp_dma_copybreak = 4096 net.ipv4.tcp_slow_start_after_idle = 1 net.ipv4.tcp_available_congestion_control = cubic reno net.ipv4.tcp_allowed_congestion_control = cubic reno net.ipv4.tcp_max_ssthresh = 0 net.ipv4.tcp_thin_linear_timeouts = 0 net.ipv4.tcp_thin_dupack = 0 net.ipv4.tcp_min_tso_segs = 2 //server socket listen property: private static final int RECEIVE_BUFFER = 10; private static final int SO_TIMEOUT = 0; private static final boolean REUSE_ADDR = false; private static final int BACK_LOG = 5; //client socket listen property on server endpoint: private static final boolean CLI_KEEPALIVE = false; private static final boolean CLI_OOB = false; private static final int CLI_REC_BUF = 20; private static final boolean CLI_REUSE_ADDR = false; private static final int CLI_SEND_BUF = 20; private static final boolean CLI_LINGER = false; private static final int CLI_LINGER_N = -1; private static final int CLI_TIMEOUT = 5000; private static final boolean CLI_NO_DELAY = true; ```