案例：df -h 磁盘空间还剩余很多，但是还是报错 no space left on device 。
1、 磁盘空间满了之 block满了
block是用来存储数据的，每个block的大小一般有1k、2k、4k几种，其中引导分区等为1k，其他普通分区多为4k。
[root@linux ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 8.8G 1.6G 6.8G 19% /
tmpfs 931M 0 931M 0% /dev/shm
/dev/sda1 190M 40M 141M 22% /boot
/dev/sdc 73K 14K 55K 21% /app/logs
[root@linux ~]# cd /app/logs/
[root@linux logs]# ls -lh /bin/ls
-rwxr-xr-x. 1 root root 115K Mar 23 02:52 /bin/ls
[root@linux logs]# cp /bin/ls /app/logs/
cp: writing `/app/logs/ls': No space left on device
[root@linux logs]# cp /bin/awk /app/logs/
cp: writing `/app/logs/awk': No space left on device
[root@linux logs]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 8.8G 1.6G 6.8G 19% /
tmpfs 931M 0 931M 0% /dev/shm
/dev/sda1 190M 40M 141M 22% /boot
/dev/sdc 73K 70K 0 100% /app/logs
[root@linux logs]# cd /app/logs/
[root@linux logs]# ls -lh
total 68K
-rwxr-xr-x 1 root root 0 May 20 12:39 awk
drwx------ 2 root root 12K May 20 12:36 lost+found
-rwxr-xr-x 1 root root 56K May 20 12:39 ls
解决办法：删除一些大文件
[root@linux logs]# \rm -f ls
[root@linux logs]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 8.8G 1.6G 6.8G 19% /
tmpfs 931M 0 931M 0% /dev/shm
/dev/sda1 190M 40M 141M 22% /boot
/dev/sdc 73K 14K 55K 21% /app/logs
2、磁盘空间满了之 inode用光了
inode 称为索引节点(编号)<=>相当于人的身份证,家庭住址,全国唯一(在不同的分区中是独一无二的)作用存放文件的属性信息及block的位置。
[root@linux logs]# pwd
/app/logs
[root@linux logs]# touch {1..6}.txt
touch: cannot touch `6.txt': No space left on device
[root@linux logs]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 8.8G 1.6G 6.8G 19% /
tmpfs 931M 0 931M 0% /dev/shm
/dev/sda1 190M 40M 141M 22% /boot
/dev/sdc 73K 14K 55K 21% /app/logs
[root@linux logs]# touch test.txt
touch: cannot touch `test.txt': No space left on device
[root@oldboy-40 logs]# df -i
Filesystem Inodes IUsed IFree IUse% Mounted on
/dev/sda3 593344 57034 536310 10% /
tmpfs 238282 1 238281 1% /dev/shm
/dev/sda1 51200 39 51161 1% /boot
/dev/sdc 16 16 0 100% /app/logs
[root@oldboy-40 logs]# ls -l
total 12
-rw-r--r-- 1 root root 0 May 20 12:43 1.txt
-rw-r--r-- 1 root root 0 May 20 12:43 2.txt
-rw-r--r-- 1 root root 0 May 20 12:43 3.txt
-rw-r--r-- 1 root root 0 May 20 12:43 4.txt
-rw-r--r-- 1 root root 0 May 20 12:43 5.txt
drwx------ 2 root root 12288 May 20 12:36 lost+found解决办法：删除一些小文件
[root@linux logs]# \rm -f *.txt
[root@linux logs]# df -i
Filesystem Inodes IUsed IFree IUse% Mounted on
/dev/sda3 593344 57034 536310 10% /
tmpfs 238282 1 238281 1% /dev/shm
/dev/sda1 51200 39 51161 1% /boot
3、block文件没有彻底删除 - 硬链接数为0,进程调用不为o lsof |grep delete
[root@linux logs]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 18G 16.2G 2G 90% /
tmpfs 931M 0 931M 0% /dev/shm
tmpfs 489M 0 489M 0% /dev/shm
tmpfs 489M 56M 433M 12% /run
tmpfs 489M 0 489M 0% /sys/fs/cgroup
tmpfs 98M 0 98M 0% /run/user/0
[root@linux-node1 ~]# du -sh /*
0 /bin
103M /boot
0 /dev
36M /etc
0 /home
0 /lib
0 /lib64
0 /media
0 /mnt
974M /opt
du: cannot access ‘/proc/80695/task/80695/fd/4’: No such file or directory
du: cannot access ‘/proc/80695/task/80695/fdinfo/4’: No such file or directory
du: cannot access ‘/proc/80695/fd/4’: No such file or directory
du: cannot access ‘/proc/80695/fdinfo/4’: No such file or directory
0 /proc
2.6M /root
50M /run
0 /sbin
0 /srv
0 /sys
4.0K /tmp
4.7G /usr
502M /var
解决办法: lsof |grep delete查找没有关闭的调用进程 重启该进程
[root@linux ~]# lsof |grep deleted
rsyslogd 1248 root 1w REG 8,3 4888889152 140769/var/log/messages (deleted)
[root@linux ~]# /etc/init.d/rsyslog restart
Shutting down system logger: [ OK ]
Starting system logger: [ OK ]
[root@linux logs]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 18G 6.3G 12G 35% /
tmpfs 931M 0 931M 0% /dev/shm
tmpfs 489M 0 489M 0% /dev/shm
tmpfs 489M 56M 433M 12% /run
tmpfs 489M 0 489M 0% /sys/fs/cgroup
tmpfs 98M 0 98M 0% /run/user/0