怎样给centos系统扩展磁盘分区

问题/故障/场景/需求

eve-ng的虚拟机ova的硬盘只有38G，需要增加空间，在vmware直接扩展硬盘后，重启系统，使用fdisk -l可以看到硬盘扩大了，但文件系统并没有扩大，还需要将这些新增的空间扩展分配到某个文件系统才行。下面记录了整个扩展过程

解决方法/步骤

1. 在VM里扩大磁盘到250G重启系统后，查看当前的文件系统的情况

root@eve-ng:~# df -hFilesystem                    Size  Used Avail Use% Mounted onudev                          7.9G     0  7.9G   0% /devtmpfs                         1.6G   19M  1.6G   2% /run/dev/mapper/eve--ng--vg-root   38G   13G   23G  36% /tmpfs                         7.9G     0  7.9G   0% /dev/shmtmpfs                         5.0M     0  5.0M   0% /run/locktmpfs                         7.9G     0  7.9G   0% /sys/fs/cgroup/dev/sda1                     472M   83M  365M  19% /bootroot@eve-ng:~# fdisk -l...省略部分内容Disk /dev/sda: 250 GiB, 268435456000 bytes, 524288000 sectors   //可以看到已经有250G了Units: sectors of 1 * 512 = 512 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisklabel type: dosDisk identifier: 0x3e3ca055Device     Boot   Start      End  Sectors  Size Id Type/dev/sda1  *       2048   999423   997376  487M 83 Linux/dev/sda2       1001470 83884031 82882562 39.5G  5 Extended/dev/sda5       1001472 83884031 82882560 39.5G 8e Linux LVMDisk /dev/mapper/eve--ng--vg-root: 38.6 GiB, 41406169088 bytes, 80871424 sectorsUnits: sectors of 1 * 512 = 512 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk /dev/mapper/eve--ng--vg-swap_1: 980 MiB, 1027604480 bytes, 2007040 sectorsUnits: sectors of 1 * 512 = 512 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytes//下面执行分区root@eve-ng:~# fdisk /dev/sdaWelcome to fdisk (util-linux 2.27.1).Changes will remain in memory only, until you decide to write them.Be careful before using the write command.Command (m for help): nPartition type   p   primary (1 primary, 1 extended, 2 free)   l   logical (numbered from 5)Select (default p): pPartition number (3,4, default 3): 3First sector (999424-524287999, default 999424): 83884032 //注意，这里是之前分配的最后一块（sda5 end）加一（83884031+1）Last sector, +sectors or +size{K,M,G,T,P} (83884032-524287999, default 524287999): //注意看这是不是最后一块Created a new partition 3 of type 'Linux' and of size 210 GiB.Command (m for help): tPartition number (1-3,5, default 5): 3 3Partition type (type L to list all types): 8eChanged type of partition 'Linux' to 'Linux LVM'.Command (m for help): wThe partition table has been altered.Calling ioctl() to re-read partition table.Re-reading the partition table failed.: Device or resource busyThe kernel still uses the old table. The new table will be used at the next reboot or after you run partprobe(8) or kpartx(8).root@eve-ng:~# rebootroot@eve-ng:~# pvcreate /dev/sda3  Physical volume "/dev/sda3" successfully createdroot@eve-ng:~# vgdisplay  --- Volume group ---  VG Name               eve-ng-vg  System ID  Format                lvm2  Metadata Areas        1  Metadata Sequence No  3  VG Access             read/write  VG Status             resizable  MAX LV                0  Cur LV                2  Open LV               2  Max PV                0  Cur PV                1  Act PV                1  VG Size               39.52 GiB  PE Size               4.00 MiB  Total PE              10117  Alloc PE / Size       10117 / 39.52 GiB  Free  PE / Size       0 / 0  VG UUID               EvwUbc-nfsg-dHqA-znxB-U3gv-V782-Q8ZxkIroot@eve-ng:~# vgextend eve-ng-vg /dev/sda3  Volume group "eve-ng-vg" successfully extendedroot@eve-ng:~# vgdisplay  --- Volume group ---  VG Name               eve-ng-vg  System ID  Format                lvm2  Metadata Areas        2  Metadata Sequence No  4  VG Access             read/write  VG Status             resizable  MAX LV                0  Cur LV                2  Open LV               2  Max PV                0  Cur PV                2  Act PV                2  VG Size               249.52 GiB  PE Size               4.00 MiB  Total PE              63877  Alloc PE / Size       10117 / 39.52 GiB  Free  PE / Size       53760 / 210.00 GiB  VG UUID               EvwUbc-nfsg-dHqA-znxB-U3gv-V782-Q8ZxkIroot@eve-ng:~# lvdisplay  --- Logical volume ---  LV Path                /dev/eve-ng-vg/root  LV Name                root  VG Name                eve-ng-vg  LV UUID                ktUpR0-VpqS-rJJv-a1FC-u6Gd-U8yN-2WYQ53  LV Write Access        read/write  LV Creation host, time eve-ng, 2018-03-21 02:25:21 +0200  LV Status              available  # open                 1  LV Size                38.56 GiB  Current LE             9872  Segments               1  Allocation             inherit  Read ahead sectors     auto  - currently set to     256  Block device           253:0//扩展逻辑卷root@eve-ng:~# lvextend -l +100%FREE /dev/eve-ng-vg/root  Size of logical volume eve-ng-vg/root changed from 38.56 GiB (9872 extents) to 248.56 GiB (63632 extents).  Logical volume root successfully resized.root@eve-ng:~# df -hFilesystem                    Size  Used Avail Use% Mounted onudev                          7.9G     0  7.9G   0% /devtmpfs                         1.6G   19M  1.6G   2% /run/dev/mapper/eve--ng--vg-root   38G   13G   23G  36% /tmpfs                         7.9G     0  7.9G   0% /dev/shmtmpfs                         5.0M     0  5.0M   0% /run/locktmpfs                         7.9G     0  7.9G   0% /sys/fs/cgroup/dev/sda1                     472M   83M  365M  19% /boot//在线扩容,要先查看当前的文件系统的类型，可以通过cat /etc/fstab来查看root@eve-ng:~# resize2fs /dev/eve-ng-vg/rootresize2fs 1.42.13 (17-May-2015)Filesystem at /dev/eve-ng-vg/root is mounted on /; on-line resizing requiredold_desc_blocks = 3, new_desc_blocks = 16The filesystem on /dev/eve-ng-vg/root is now 65159168 (4k) blocks long.root@eve-ng:~# df -hFilesystem                    Size  Used Avail Use% Mounted onudev                          7.9G     0  7.9G   0% /devtmpfs                         1.6G   19M  1.6G   2% /run/dev/mapper/eve--ng--vg-root  245G   13G  222G   6% /tmpfs                         7.9G     0  7.9G   0% /dev/shmtmpfs                         5.0M     0  5.0M   0% /run/locktmpfs                         7.9G     0  7.9G   0% /sys/fs/cgroup/dev/sda1                     472M   83M  365M  19% /boot

参考

在线扩容

使用 resize2fs或xfs_growfs 对挂载目录在线扩容

• resize2fs 针对文件系统ext2 ext3 ext4
• xfs_growfs 针对文件系统xfs