Linux-FAQ
import BrowserWindow from '@site/src/components/BrowserWindow';
无法连接网络
# 1. 查看网关
route -n
# 设置默认网关
route add default gw 10.8.30.1
# 2. 以上不行执行下面命令
dhclient eno1
软件安装卸载总是报错
dpkg: 处理软件包 redis-server (--configure)时出错： 子进程 已安装 post-installation 脚本 返回错误状态 1
sudo rm /var/lib/dpkg/info/redis-server.*
linux 根目录空间不足，追加空间到根目录下
问题分析
k8s pod 异常，无法启动
kubectl get po -n kuboard -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
...
node-exporter-g2rmq 2/2 Running 0 7d1h 10.8.40.128 node-03 <none> <none>
node-exporter-j8kf2 2/2 Running 0 7d1h 10.8.40.127 node-04 <none> <none>
node-exporter-rg4sx 0/2 Evicted 0 17s <none> node-05 <none> <none>
prometheus-adapter-844ff4584c-dzsrg 1/1 Running 0 6d1h 100.160.227.47 node-04 <none> <none>
...
...
查看详细信息
root@master-03:~# kubectl describe po -n kuboard node-exporter-rg4sx
...
...
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 43s default-scheduler Successfully assigned kuboard/node-exporter-rg4sx to node-05
Warning Evicted 44s kubelet The node had condition: [DiskPressure].
远程到指定的节点，查看磁盘
root@master-03:~# ssh node-05
root@node-05:~# df -lh
Filesystem Size Used Avail Use% Mounted on
udev 32G 0 32G 0% /dev
tmpfs 6.3G 3.7M 6.3G 1% /run
/dev/mapper/node17--vg-root 28G 24G 2.7G 90% /
tmpfs 32G 0 32G 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
/dev/sdb2 471M 87M 360M 20% /boot
/dev/sdb1 511M 5.8M 506M 2% /boot/efi
/dev/mapper/node17--vg-home 3.6T 72K 3.4T 1% /home
tmpfs 60G 8.0K 60G 1% /var/lib/kubelet/pods/6266bed1-51ab-4a89-a540-1fb3735edb73/volumes/kubernetes.io~secret/node-certs
tmpfs 60G 8.0K 60G 1% /var/lib/kubelet/pods/51f33968-5bdd-4b11-a34f-df044082d4aa/volumes/kubernetes.io~projected/ceph-csi-configs
tmpfs 6.3G 0 6.3G 0% /run/user/0
...
...
可以看到，根目录下空间确实不足， /home 下空间超大，所以我们把 /home 下部分空间 分给 根目录
解决思路
- 备份
/home - 删除
/home - 扩展
/ - 新建
/home - 恢复
/home
详细操作过程如下
root@node-05:~# tar cvf home.tar /home
root@node-05:~# apt-get update
Hit:1 http://mirrors.163.com/debian bullseye InRelease
Get:2 http://mirrors.163.com/debian bullseye-updates InRelease [44.1 kB]
Fetched 44.1 kB in 0s (114 kB/s)
Reading package lists... Done
# 安装 `fuser` 命令
root@node-05:~# apt-get install psmisc
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following NEW packages will be installed:
psmisc
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 198 kB of archives.
After this operation, 812 kB of additional disk space will be used.
Get:1 http://mirrors.163.com/debian bullseye/main amd64 psmisc amd64 23.4-2 [198 kB]
Fetched 198 kB in 0s (708 kB/s)
Selecting previously unselected package psmisc.
(Reading database ... 34977 files and directories currently installed.)
Preparing to unpack .../psmisc_23.4-2_amd64.deb ...
Unpacking psmisc (23.4-2) ...
Setting up psmisc (23.4-2) ...
Processing triggers for man-db (2.9.4-2) ...
# 卸载 `/home` 目录
root@node-05:~# fuser -km /home/
root@node-05:~# lvextend -L +2T /dev/mapper/node17--vg-root
Insufficient free space: 524288 extents needed, but only 0 available
root@node-05:~# umount /home
# 删除 `/home` 目录
root@node-05:~# lvremove /dev/mapper/node17--vg-home
Do you really want to remove active logical volume node17-vg/home? [y/n]: y
Logical volume "home" successfully removed
# 扩展根目录
root@node-05:~# lvextend -L +2T /dev/mapper/node17--vg-root
Size of logical volume node17-vg/root changed from <27.94 GiB (7152 extents) to <2.03 TiB (531440 extents).
Logical volume node17-vg/root successfully resized.
# 重置 根目录大小
root@node-05:~# resize2fs /dev/mapper/node17--vg-root
resize2fs 1.46.2 (28-Feb-2021)
Filesystem at /dev/mapper/node17--vg-root is mounted on /; on-line resizing required
old_desc_blocks = 4, new_desc_blocks = 260
The filesystem on /dev/mapper/node17--vg-root is now 544194560 (4k) blocks long.
# 新建 `/home` 目录
root@node-05:~# lvcreate -L 1.6T -n /dev/mapper/node17--vg-home
Rounding up size to full physical extent 1.60 TiB
Logical volume "home" created.
root@node-05:~# mkfs.ext4 /dev/mapper/node17--vg-home
mke2fs 1.46.2 (28-Feb-2021)
Creating filesystem with 429497344 4k blocks and 107380736 inodes
Filesystem UUID: 86d2b9b2-6bd3-4bf3-89d4-b8adbda382c4
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
102400000, 214990848
Allocating group tables: done
Writing inode tables: done
Creating journal (262144 blocks): done
Writing superblocks and filesystem accounting information: done
# 重新挂载 `/home` 目录
root@node-05:~# mount /dev/mapper/node17--vg-home
# 恢复 `/home`
root@node-05:~# tar xvf home.tar -C /
tip
如果报错如下：
lvextend command not found
用下面命令安装下 lvm2
apt-get install lvm2
现在查看目录大小
root@node-05:~# df -lh
Filesystem Size Used Avail Use% Mounted on
udev 32G 0 32G 0% /dev
tmpfs 6.3G 3.7M 6.3G 1% /run
/dev/mapper/node17--vg-root 2.0T 24G 1.9T 2% /
tmpfs 32G 0 32G 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
/dev/sdb2 471M 87M 360M 20% /boot
/dev/sdb1 511M 5.8M 506M 2% /boot/efi
overlay 2.0T 24G 1.9T 2% /run/containerd/io.containerd.runtime.v2.task/k8s.io/d39eaef706d8a0f2374ca04ba6c60327443be63da1a5517808be7d63db52a6ab/rootfs
overlay 2.0T 24G 1.9T 2% /run/containerd/io.containerd.runtime.v2.task/k8s.io/693bafb7d83ceddfe324d4bef33b633ed9ca253a82e0b8bfcac2c5cded5ba3ad/rootfs
overlay 2.0T 24G 1.9T 2% /run/containerd/io.containerd.runtime.v2.task/k8s.io/e4d0d938bc975f28cb3982b9a4d44ce0d7ed2915c6d306d3cff5738f96b3b23d/rootfs
overlay 2.0T 24G 1.9T 2% /run/containerd/io.containerd.runtime.v2.task/k8s.io/e30a7fd7779916efac0b3459af4329324c883c3707d9b2c80d57d89077d11afc/rootfs
tmpfs 60G 0 60G 0% /var/lib/kubelet/pods/4a0ee2d6-e72d-43d4-a6d3-369291f6d557/volumes/kubernetes.io~empty-dir/keys-tmp-dir
tmpfs 60G 12K 60G 1% /var/lib/kubelet/pods/4a0ee2d6-e72d-43d4-a6d3-369291f6d557/volumes/kubernetes.io~projected/kube-api-access-ljl4m
tmpfs 6.3G 0 6.3G 0% /run/user/0
/dev/mapper/node17--vg-home 1.6T 72K 1.5T 1% /home
最后删除 /home 备份文件
root@node-05:~# rm home.tar
ubuntu read-only file system
fsck -f /dev/sda2