Ubuntu问题及技巧整理

整理一些工作中遇到的问题以及好的技巧

网卡识别乱序

打开/etc/udev/rules.d/70-persistent-net.rules 文件,按照你想要的顺序重新编辑,然后重启机器。

iscsi挂载LUN

主机内操作如下:

发现
iscsiadm --mode discovery --type sendtargets --portal 172.26.0.1
172.26.0.1:3260,257 iqn.2006-08.com.huawei:oceanstor:210004f938ebfdb4::20100:172.26.0.1

登录
iscsiadm -m node -T iqn.2006-08.com.huawei:oceanstor:210004f938ebfdb4::20100:172.26.0.1 -l

退出
iscsiadm -m node -T iqn.2006-08.com.huawei:oceanstor:210004f938ebfdb4::20100:172.26.0.1 -u

查看iscsi连接
iscsiadm -m session

删除登录痕迹
iscsiadm -m node -T iqn.2011-09.com.example.ts1:disk1 -p 172.26.0.1:3260 -o delete

查看客户端iqn
/etc/iscsi/initiatorname.iscsi

网卡出现p1p1

修改 /etc/default/grub

GRUB_CMDLINE_LINUX_DEFAULT="biosdevname=0 quiet splash"
GRUB_CMDLINE_LINUX="biosdevname=0"

修改 /etc/udev/rules.d/70-persistent-net.rules 把网卡映射信息配置好, 比如:

SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="04:f9:38:9a:7b:ec", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth1"

# PCI device 0x14e4:0x1657 (tg3)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="04:f9:38:9a:7b:ee", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth3"

# PCI device 0x14e4:0x1657 (tg3)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="04:f9:38:9a:7b:ed", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth2"

# PCI device 0x14e4:0x1657 (tg3)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="04:f9:38:9a:7b:eb", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"

SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="ac:85:3d:9f:58:12", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth4"
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="ac:85:3d:9f:58:13", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth5"

执行update-grub

reboot重启机器后,即可修复。

内核优化参数

内核优化参数:

kernel.msgmnb = 65536
# Controls the default maxmimum size of a mesage queue
kernel.msgmax = 65536
# Controls the maximum shared segment size, in bytes
kernel.shmmax = 68719476736
# Controls the maximum number of shared memory segments, in pages
kernel.shmall = 4294967296
kernel.shmmni = 4096
kernel.sem = 50100 64128000 50100 1280
fs.file-max = 7672460
net.ipv4.ip_local_port_range = 9000 65000
net.core.rmem_default = 1048576
net.core.rmem_max = 4194304
net.core.wmem_default = 262144
net.core.wmem_max = 1048576
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_max_syn_backlog = 4096
net.core.netdev_max_backlog = 10000
vm.overcommit_memory = 0
net.ipv4.ip_conntrack_max = 655360
fs.aio-max-nr = 1048576
net.ipv4.tcp_timestamps = 0


/etc/security/limits.conf
* soft    nofile  131072
* hard    nofile  131072
* soft    nproc   131072
* hard    nproc   131072
* soft    core    unlimited
* hard    core    unlimited
* soft    memlock 50000000
* hard    memlock 50000000

swap分区设置

内存小于4GB时,推荐不少于2GB的swap空间;

内存4GB~16GB,推荐不少于4GB的swap空间;

内存16GB~64GB,推荐不少于8GB的swap空间;

内存64GB~256GB,推荐不少于16GB的swap空间。

自动装载内核模块

把要每次系统启动要自动装载的模块,写入/etc/modules,比如:

$ cat /etc/modules
acpiphp
8021q

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