不重启的情况下重读分区
补充说明partprobe命令 用于重读分区表，当出现删除文件后，出现仍然占用空间。可以partprobe在不重启的情况下重读分区。
语法 partprobe(选项)(参数) 选项 -d：不更新内核；-s：显示摘要和分区；-h：显示帮助信息；-v：显示版本信息。 参数设备：指定需要确认分区表改变的硬盘对应的设备文件。
实例使用partprobe不重启系统添加新的磁盘分区，主机自带硬盘超过300GB，目前只划分使用了3个主分区，不到70GB，如下：
[root@localhost ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/sda1 29G 3.7G 24G 14% / /dev/sda2 29G 22G 5.2G 81% /oracle tmpfs 2.0G 0 2.0G 0% /dev/shm [root@localhost ~]# cat /proc/partitionsmajor minor #blocks name 8 0 311427072 sda 8 1 30716248 sda1 8 2 30716280 sda2 8 3 8193150 sda3 8 16 976896 sdb 8 32 976896 sdc…省略其他现在需要给系统添加1个100GB的空间存放数据文件，而又不影响现有系统上业务的运行，使用fdisk结合partprobe命令不重启系统添加一块新的磁盘分区。操作步骤如下：
第1步 添加新的磁盘分区 ：
[root@localhost ~]# fdisk /dev/sdaThe number of cylinders for this disk is set to 38770.There is nothing wrong with that, but this is larger than 1024,and could in certain setups cause problems with:1) software that runs at boot time (e.g., old versions of lilo)2) booting and partitioning software from other OSs (e.g., DOS FDISK, OS/2 FDISK)command (m for help): pDisk /dev/sda: 318.9 GB, 318901321728 bytes255 heads, 63 sectors/track, 38770 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks id System/dev/sda1 * 1 3824 30716248+ 83 Linux/dev/sda2 3825 7648 30716280 83 Linux/dev/sda3 7649 8668 8193150 82 Linux swap / SolarisCommand (m for help): nCommand action e extended p primary partition (1-4)pSelected partition 4First cylinder (8669-38770, default 8669):Using default value 8669last cylinder or +size or +sizeM or +sizeK (8669-38770, default 38770): +100G Command (m for help): wThe partition table has been altered!Calling ioctl() to re-read partition table.WARNING: Re-reading the partition table failed with error 16: Device or resource busy.The kernel still uses the old table.The new table will be used at the next reboot.Syncing disks.第2步 使用工具partprobe让kernel读取分区信息：
[root@localhost ~]# partprobe使用fdisk工具只是将分区信息写到磁盘，如果需要mkfs磁盘分区则需要重启系统，而使用partprobe则可以使kernel重新读取分区信息，从而避免重启系统。
第3步 格式化文件系统：
[root@localhost ~]# mkfs.ext3 /dev/sda4mke2fs 1.39 (29-May-2006)Filesystem label=OS type: LinuxBlock size=4096 (log=2)Fragment size=4096 (log=2)12222464 inodes, 24416791 blocks1220839 blocks (5.00%) reserved for the super userFirst data block=0Maximum filesystem blocks=4294967296746 block groups32768 blocks per group, 32768 fragments per group16384 inodes per groupSuperblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 4096000, 7962624, 11239424, 20480000, 23887872Writing inode tables: doneCreating journal (32768 blocks): doneWriting superblocks and filesystem accounting information:doneThis filesystem will be automatically checked every 26 mounts or180 days, whichever comes first. Use tune2fs -c or -i to override.[root@localhost ~]#第4步 mount新的分区/dev/sda4：
[root@localhost ~]# e2label /dev/sda4 /data[root@localhost ~]# mkdir /data[root@localhost ~]# mount /dev/sda4 /data[root@localhost ~]# dfFilesystem 1K-blocks Used Available Use% Mounted on/dev/sda1 29753556 3810844 24406900 14% //dev/sda2 29753588 11304616 16913160 41% /oracletmpfs 2023936 0 2023936 0% /dev/shm/dev/sda4 96132968 192312 91057300 1% /data使用partprobe可以不用重启系统即可配合fdisk工具创建新的分区。
转自：https://jaywcjlove.github.io/linux-command/c/partprobe.html