运维笔记

centos7根目录满了如何清理，根目录满了导致无法远程解决办法

Sat, 10 Oct 2026 10:19:32 +0800

df -h 查看磁盘使用率
先清理几个最大的系统日志：
truncate -s 0 /var/log/messages
truncate -s 0 /var/log/secure
truncate -s 0 /var/log/maillog
执行df -h查看使用率，再执行 find / -xdev -type f -size +100M 2>/dev/null 查看什么文件占用的空间多

问题找到了！大量core.*核心转储文件 /root/core.xxxx 这些是 core dump内核转储文件，程序崩溃的时候系统生成的内存快照，单个文件体积巨大，一堆堆堆积在/root目录，直接把50G根分区占满！

4.删除全部core文件 rm -f /root/core.* 执行完 df -h查看使用率

5.永久关闭core文件生成，防止以后继续塞满磁盘 echo "* soft core 0" >> /etc/security/limits.conf

6.磁盘爆满容易损坏密钥，导致ssh远程不上，检查ssh主机密钥文件是否完整

ls -lh /etc/ssh/ssh_host_*

必须看到这一批密钥文件：ssh_host_rsa_key 等如果文件大小为0，代表磁盘打满时密钥被破坏，需要重新生成主机密钥

7.重新生成全套ssh主机秘钥：

rm -f /etc/ssh/ssh_host_*_key*

ssh-keygen -A

8、重启sshd服务

systemctl restart sshd

9.测试远程正常了

宿迁地区海外域名可以ping通但无法访问

Fri, 09 Oct 2026 10:04:32 +0800

默认MTU为1500，需要把MTU值修改为1420，以下都已修改为1420为例

windows系统

1.管理员运行CMD

2.查看当前网卡名称和 MTU

netsh interface ipv4 show subinterfaces

3.把目标网卡的 MTU 设为 1420

netsh interface ipv4 set subinterface "以太网" mtu=1420 store=persistent

4.验证是否生效，看到该网卡的 MTU 变成 1420 即成功

netsh interface ipv4 show subinterfaces

老版windows系统

老版系统会有中文字符不匹配的问题，这时候需要用网卡Idx定位网卡

1、查看网卡索引 Idx

netsh interface ipv4 show interfaces
#输出样例：
Idx     Met         MTU          State                Name
---  ----------  ----------  ------------  ---------------------------
  1          50  4294967295  connected     Loopback Pseudo-Interface 1
 10          20        1500  connected     本地连接

2.用索引号设置 MTU=1420

netsh interface ipv4 set subinterface 10 mtu=1420 store=persistent

CentOS7 / Rocky / AlmaLinux系统

1.直接在网卡配置文件添加一行MTU=1420

echo MTU=1420 >> /etc/sysconfig/network-scripts/ifcfg-eth0

2.重启网卡

systemctl restart network

CentOS8+/RHEL8+

# 查看连接名 
nmcli connection show
#设置MTU，引号内是连接名称 
nmcli connection modify "Wired connection 1" ethernet.mtu 1420 
# 重载生效 
nmcli connection up "Wired connection 1"

Ubuntu

1.打开网卡配置文件

sudo nano /etc/netplan/00-installer-config.yaml

2.配置yaml文件，在网卡下加一行mut: 1420 （严格空格，不能 tab）

3.启用配置

sudo netplan try
sudo netplan apply

4.校验

ip a

Debian

1.打开网卡配置文件

vi /etc/network/interfaces

2.网卡配置里加一行mtu 1420

3.重启网卡

systemctl restart networking

CentOS7 的双万兆口聚合 bond 配置

Wed, 16 Sep 2026 01:54:36 +0800

1.先创建bond 配置文件

vi /etc/sysconfig/network-scripts/ifcfg-bond0

具体内容如下(IP自行修改)

DEVICE=bonde
NAME=bonde
TYPE=Bond
BONDING_MASTER=yes
BOOTPROTO=static
ONBOOT=yes
IPADDR=10.0.0.10
PREFIX=24
GATEWAY=10.0.0.1
DNS1=223.5.5.5
DNS2=114.114.114.114
# LACP关键参数
BONDING_OPTS="mode=4 miimon=100 lacp_rate=fast xmit_hash_policy=layer3+4"

2.修改网卡文件

ifcfg-ens2f0

DEVICE=ens2f0
NAME=ens2f0
TYPE=Ethernet
BOOTPROTO=none
ONBOOT=yes
MASTER=bond0
SLAVE=yes

ifcfg-ens2f1

DEVICE=ens2f1
NAME=ens2f1
TYPE=Ethernet
BOOTPROTO=none
ONBOOT=yes
MASTER=bond0
SLAVE=yes

3.加载bond模块

modprobe bonding
echo "bonding" > /etc/modules-load.d/bonding.conf

4.重启网络

#关闭NM，避免冲突
systemctl stop NetworkManager
systemctl disable NetworkManager
systemctl restart network

5.查看bond状态

#看bond详细信息，确认Mode、Slave、LAcP状态
cat /proc/net/bonding/bonde
#看网卡速率
ethtool ens2f0
ethtool ens2f1

6.交换机配置

将两个网口都放到同一个Trunk下，Trunk链路聚合设置为静态LACP模式(mode lacp-static)，Trunk具体设置如下

网口设置如下

超威服务器修改IPMI 密码

Wed, 02 Sep 2026 14:30:32 +0800

1.安装IPMITOOL

yum install ipmitool -y

2.执行以下命令加载内核

modprobe ipmi_msghandler

modprobe ipmi_devintf

modprobe ipmi_si

3.执行以下命令，若正常显示当前BMC的信息，表示内核已经加载ipmitool工具

ipmitool lan print 1

4.执行以下命令查看BMC用户信息

ipmitool user list 1

5.执行以下命令设置BMC用户密码

ipmitool user set password 2 新密码

centos校准系统时间

Wed, 17 Jun 2026 20:10:46 +0800

1.安装chorony

yum install -y chrony

2.配置chorony文件

vi /etc/chrony.conf

在最后添加

pool ntp.aliyun.com iburst
pool ntp.tencent.com iburst

3.启动服务然后等一会

systemctl start chronyd

centos stream 9 更换阿里源

Fri, 22 May 2026 14:51:19 +0800

CentOS9操作系统yum源配置文件主要有两个，分别是centos.repo和centos-addons.repo

centos.repo 配置文件是 CentOS 系统中用于配置 yum 软件仓库（repository）的文件。这个文件定义了 yum 从哪些 URL 地址获取软件包。
路径：/etc/yum.repos.d/centos.repo

centos-addons.repo 配置文件是 CentOS 系统中用于配置额外软件仓库（repository）的 yum 配置文件。这个文件允许用户添加除了基础仓库之外的额外软件包源，以便安装那些不在基础仓库中的软件包。
路径：/etc/yum.repos.d/centos-addons.repo

备份文件

# 备份 centos.repomv /etc/yum.repos.d/centos.repo /etc/yum.repos.d/centos.repo.backup

#备份 centos-addons.repomv /etc/yum.repos.d/centos-addons.repo /etc/yum.repos.d/centos-addons.repo.backup

修改yum源

新建/etc/yum.repos.d/centos.repo 文件和 /etc/yum.repos.d/centos-addons.repo文件

centos.repo文件内容

[baseos]

name=CentOS Stream $releasever - BaseOS

baseurl=https://mirrors.aliyun.com/centos-stream/$stream/BaseOS/$basearch/os/

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

gpgcheck=1

repo_gpgcheck=0

metadata_expire=6h

countme=1

enabled=1

[baseos-debug]

name=CentOS Stream $releasever - BaseOS - Debug

baseurl=https://mirrors.aliyun.com/centos-stream/$stream/BaseOS/$basearch/debug/tree/

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

gpgcheck=1

repo_gpgcheck=0

metadata_expire=6h

enabled=0

[baseos-source]

name=CentOS Stream $releasever - BaseOS - Source

baseurl=https://mirrors.aliyun.com/centos-stream/$stream/BaseOS/source/tree/

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

gpgcheck=1

repo_gpgcheck=0

metadata_expire=6h

enabled=0

[appstream]

name=CentOS Stream $releasever - AppStream

baseurl=https://mirrors.aliyun.com/centos-stream/$stream/AppStream/$basearch/os/

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

gpgcheck=1

repo_gpgcheck=0

metadata_expire=6h

countme=1

enabled=1

[appstream-debug]

name=CentOS Stream $releasever - AppStream - Debug

baseurl=https://mirrors.aliyun.com/centos-stream/$stream/AppStream/$basearch/debug/tree/

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

gpgcheck=1

repo_gpgcheck=0

metadata_expire=6h

enabled=0

[appstream-source]

name=CentOS Stream $releasever - AppStream - Source

baseurl=https://mirrors.aliyun.com/centos-stream/$stream/AppStream/$basearch/debug/tree/

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

gpgcheck=1

repo_gpgcheck=0

metadata_expire=6h

enabled=0

[crb]

name=CentOS Stream $releasever - CRB

baseurl=https://mirrors.aliyun.com/centos-stream/$stream/CRB/$basearch/os/

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

gpgcheck=1

repo_gpgcheck=0

metadata_expire=6h

countme=1

enabled=0

[crb-debug]

name=CentOS Stream $releasever - CRB - Debug

baseurl=https://mirrors.aliyun.com/centos-stream/$stream/CRB/$basearch/debug/tree/

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

gpgcheck=1

repo_gpgcheck=0

metadata_expire=6h

enabled=0

[crb-source]

name=CentOS Stream $releasever - CRB - Source

baseurl=https://mirrors.aliyun.com/centos-stream/$stream/CRB/source/tree/

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

gpgcheck=1

repo_gpgcheck=0

metadata_expire=6h

enabled=0

centos-addons.repo文件内容

[highavailability]

name=CentOS Stream $releasever - HighAvailability

baseurl=http://mirrors.aliyun.com/centos-stream/$stream/HighAvailability/$basearch/os/

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

gpgcheck=1

repo_gpgcheck=0

metadata_expire=6h

countme=1

enabled=0

[highavailability-debug]

name=CentOS Stream $releasever - HighAvailability - Debug

baseurl=http://mirrors.aliyun.com/centos-stream/$stream/HighAvailability/$basearch/debug/tree/

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

gpgcheck=1

repo_gpgcheck=0

metadata_expire=6h

enabled=0

[highavailability-source]

name=CentOS Stream $releasever - HighAvailability - Source

baseurl=http://mirrors.aliyun.com/centos-stream/$stream/HighAvailability/source/tree/

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

gpgcheck=1

repo_gpgcheck=0

metadata_expire=6h

enabled=0

[nfv]

name=CentOS Stream $releasever - NFV

baseurl=http://mirrors.aliyun.com/centos-stream/$stream/NFV/$basearch/os/

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

gpgcheck=1

repo_gpgcheck=0

metadata_expire=6h

countme=1

enabled=0

[nfv-debug]

name=CentOS Stream $releasever - NFV - Debug

baseurl=http://mirrors.aliyun.com/centos-stream/$stream/NFV/$basearch/debug/tree/

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

gpgcheck=1

repo_gpgcheck=0

metadata_expire=6h

enabled=0

[nfv-source]

name=CentOS Stream $releasever - NFV - Source

baseurl=http://mirrors.aliyun.com/centos-stream/$stream/NFV/source/tree/

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

gpgcheck=1

repo_gpgcheck=0

metadata_expire=6h

enabled=0

[rt]

name=CentOS Stream $releasever - RT

baseurl=http://mirrors.aliyun.com/centos-stream/$stream/RT/$basearch/os/

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

gpgcheck=1

repo_gpgcheck=0

metadata_expire=6h

countme=1

enabled=0

[rt-debug]

name=CentOS Stream $releasever - RT - Debug

baseurl=http://mirrors.aliyun.com/centos-stream/$stream/RT/$basearch/debug/tree/

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

gpgcheck=1

repo_gpgcheck=0

metadata_expire=6h

enabled=0

[rt-source]

name=CentOS Stream $releasever - RT - Source

baseurl=http://mirrors.aliyun.com/centos-stream/$stream/RT/source/tree/

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

gpgcheck=1

repo_gpgcheck=0

metadata_expire=6h

enabled=0

[resilientstorage]

name=CentOS Stream $releasever - ResilientStorage

baseurl=http://mirrors.aliyun.com/centos-stream/$stream/ResilientStorage/$basearch/os/

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

gpgcheck=1

repo_gpgcheck=0

metadata_expire=6h

countme=1

enabled=0

[resilientstorage-debug]

name=CentOS Stream $releasever - ResilientStorage - Debug

baseurl=http://mirrors.aliyun.com/centos-stream/$stream/ResilientStorage/$basearch/debug/tree/

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

gpgcheck=1

repo_gpgcheck=0

metadata_expire=6h

enabled=0

[resilientstorage-source]

name=CentOS Stream $releasever - ResilientStorage - Source

baseurl=http://mirrors.aliyun.com/centos-stream/$stream/ResilientStorage/source/tree/

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

gpgcheck=1

repo_gpgcheck=0

metadata_expire=6h

enabled=0

[extras-common]

name=CentOS Stream $releasever - Extras packages

baseurl=http://mirrors.aliyun.com/centos-stream/SIGs/$stream/extras/$basearch/extras-common/

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-SIG-Extras-SHA512

gpgcheck=1

repo_gpgcheck=0

metadata_expire=6h

countme=1

enabled=1

[extras-common-source]

name=CentOS Stream $releasever - Extras packages - Source

baseurl=http://mirrors.aliyun.com/centos-stream/SIGs/$stream/extras/source/extras-common/

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-SIG-Extras-SHA512

gpgcheck=1

repo_gpgcheck=0

metadata_expire=6h

enabled=0

yum源生效

yum clean all
yum makecache
yum update

Centos测试磁盘读写速度

Mon, 30 Mar 2026 19:54:07 +0800

1.测试磁盘写速度

time dd if=/dev/zero of=test.dd bs=1M count=2000

2.测试磁盘读速度

time dd if=test.dd of=/dev/null bs=1M

win10系统hiberfil.sys文件占用大量空间

Wed, 04 Mar 2026 11:06:26 +0800

管理员运行命令提示符(cmd)

输入powercfg -h off

windows远程连接上不操作过几分钟就锁屏解决方法

Mon, 09 Feb 2026 08:14:41 +0800

win+r输入gpedit.msc

用户配置 → 管理模板 → 控制面板 → 个性化
启用屏幕保护程序" → 已禁用
密码保护屏幕保护程序" → 已禁用
屏幕保护程序超时" → 设置为 0

然后powershell里输入下边的更新策略就好了
gpupdate /force /target:computer
gpupdate /force /target:user

exsi配置完IP重启掉IP解决方法

Wed, 03 Dec 2025 10:35:15 +0800

1.配置完IP之后退回到最开始界面，按F12选中可选项，按F11重启检查下是否保存上