我在REHL7.0下安装oracle12c的时候提示根目录/下空间不足，于是想直接扩下根目录，网上搜索都是通过
[root@redhat6-3 ~]# resize2fs /dev/mapper/vg_redhat63-lv_root
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/mapper/vg_redhat63-lv_root is mounted on /; on-line resizing required
old desc_blocks = 2, new_desc_blocks = 2
Performing an on-line resize of /dev/mapper/vg_redhat63-lv_root to 4859904 (4k) blocks.
The filesystem on /dev/mapper/vg_redhat63-lv_root is now 4859904 blocks long.
resize2fs来做，（具体案例很多，大家一搜就有）可以在线挂硬盘，但是扩根目录文件夹的时候一直提示如下： [root@rac2 ~]# resize2fs /dev/hel/ resize2fs 1.42.9 (28-Dec-2013) resize2fs: Bad magic number in super-block while trying to open /dev/rhel/root Couldn't find valid filesystem superblock. [root@rac2 ~]# 重启也好，啥法都是试了就是一直提示，有的说umout目录，但是根目录不可能umout的，ext2online也试不行。 第三天查网帖的时候找到一篇《CentOS6、7 LVM逻辑卷分区自动扩容Shell脚本》，本来看到resize2fs感觉没啥新意，突然发现xfs_growfs ，赶紧仔细研读，（由于CentOS6和CentOS7在默认根文件系统的文件系统格式存在差异，需要判断是否为xfs，如果是xfs则应该使用xfs_growfs而不是一味的使用resize2fs。） 一句话惊醒梦中人啊，查阅了几篇xfs的用法后，在系统下一试果然好使， [root@rac2 ~]# xfs_info /dev/rhel/root meta-data=/dev/mapper/rhel-root isize=256 agcount=4, agsize=1147392 blks = sectsz=512 attr=2, projid32bit=1 = crc=0 data = bsize=4096 blocks=4589568, imaxpct=25 = sunit=0 swidth=0 blks naming =version 2 bsize=4096 ascii-ci=0 ftype=0 log =internal bsize=4096 blocks=2560, version=2 = sectsz=512 sunit=0 blks, lazy-count=1 realtime =none extsz=4096 blocks=0, rtextents=0 [root@rac2 ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/rhel-root 18G 3.0G 15G 17% / devtmpfs 905M 0 905M 0% /dev tmpfs 914M 164K 914M 1% /dev/shm tmpfs 914M 9.0M 905M 1% /run tmpfs 914M 0 914M 0% /sys/fs/cgroup /dev/sda1 497M 120M 377M 25% /boot /dev/sr0 3.5G 3.5G 0 100% /run/media/root/RHEL-7.0 Server.x86_64 [root@rac2 ~]# xfs_growfs /dev/rhel/root meta-data=/dev/mapper/rhel-root isize=256 agcount=4, agsize=1147392 blks = sectsz=512 attr=2, projid32bit=1 = crc=0 data = bsize=4096 blocks=4589568, imaxpct=25 = sunit=0 swidth=0 blks naming =version 2 bsize=4096 ascii-ci=0 ftype=0 log =internal bsize=4096 blocks=2560, version=2 = sectsz=512 sunit=0 blks, lazy-count=1 realtime =none extsz=4096 blocks=0, rtextents=0 data blocks changed from 4589568 to 9046016 [root@rac2 ~]# xfs_growfs /dev/rhel/root xfs_info /dev/rhel/root meta-data=/dev/mapper/rhel-root isize=256 agcount=8, agsize=1147392 blks = sectsz=512 attr=2, projid32bit=1 = crc=0 data = bsize=4096 blocks=9046016, imaxpct=25 = sunit=0 swidth=0 blks naming =version 2 bsize=4096 ascii-ci=0 ftype=0 log =internal bsize=4096 blocks=2560, version=2 = sectsz=512 sunit=0 blks, lazy-count=1 realtime =none extsz=4096 blocks=0, rtextents=0 [root@rac2 ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/rhel-root 35G 3.0G 32G 9% / devtmpfs 905M 0 905M 0% /dev tmpfs 914M 164K 914M 1% /dev/shm tmpfs 914M 9.0M 905M 1% /run tmpfs 914M 0 914M 0% /sys/fs/cgroup /dev/sda1 497M 120M 377M 25% /boot /dev/sr0 3.5G 3.5G 0 100% /run/media/root/RHEL-7.0 Server.x86_64 [root@rac2 ~]# 困扰了三天的问题终于解决了，晚上可以好梦了。赶紧分享大家以飨。 以下贴出扩展swap和根目录的过程，欢迎大家交流 初始状态 [root@rac1 ~]# free -m total used free shared buffers cached Mem: 1826 919 907 9 0 324 -/+ buffers/cache: 594 1232 Swap: 2047 0 2047 [root@rac1 ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/rhel-root 18G 5.0G 13G 29% / devtmpfs 908M 0 908M 0% /dev tmpfs 914M 164K 914M 1% /dev/shm tmpfs 914M 9.0M 905M 1% /run tmpfs 914M 0 914M 0% /sys/fs/cgroup /dev/sda1 497M 96M 401M 20% /boot /dev/sr0 3.5G 3.5G 0 100% /run/media/root/RHEL-7.0 Server.x86_64 [root@rac1 ~]# fdisk -l Disk /dev/sda: 21.5 GB, 21474836480 bytes, 41943040 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk label type: dos Disk identifier: 0x000aa76d Device Boot Start End Blocks Id System /dev/sda1 * 2048 1026047 512000 83 Linux /dev/sda2 1026048 41943039 20458496 8e Linux LVM Disk /dev/mapper/rhel-root: 18.8 GB, 18798870528 bytes, 36716544 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk /dev/mapper/rhel-swap: 2147 MB, 2147483648 bytes, 4194304 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes 一块20个硬盘，2G的swap，18G的根目录 [root@rac1 ~]# vgdisplay -v Finding all volume groups Finding volume group "rhel" --- Volume group --- VG Name rhel 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 19.51 GiB PE Size 4.00 MiB Total PE 4994 Alloc PE / Size 4994 / 19.51 GiB Free PE / Size 0 / 0 VG UUID cnpKO5-HowL-pwbZ-PGvi-81fk-3JXF-u5Uqte --- Logical volume --- LV Path /dev/rhel/root LV Name root VG Name rhel LV UUID 8JfkKC-nnvl-KhHD-e5wx-yISp-O3Ys-xxnVWD LV Write Access read/write LV Creation host, time localhost, 2015-04-29 17:10:28 +0800 LV Status available # open 1 LV Size 17.51 GiB Current LE 4482 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:0 --- Logical volume --- LV Path /dev/rhel/swap LV Name swap VG Name rhel LV UUID H14cCa-ignp-pPag-G9QU-sWjc-WoB3-XklFXu LV Write Access read/write LV Creation host, time localhost, 2015-04-29 17:10:29 +0800 LV Status available # open 2 LV Size 2.00 GiB Current LE 512 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:1 --- Physical volumes --- PV Name /dev/sda2 PV UUID wRff8C-8kkz-0E1N-CKLh-YnBu-7qAf-DBa8KF PV Status allocatable Total PE / Free PE 4994 / 0 [root@rac1 ~]# pvdisplay -v Scanning for physical volume names --- Physical volume --- PV Name /dev/sda2 VG Name rhel PV Size 19.51 GiB / not usable 3.00 MiB Allocatable yes (but full) PE Size 4.00 MiB Total PE 4994 Free PE 0 Allocated PE 4994 PV UUID wRff8C-8kkz-0E1N-CKLh-YnBu-7qAf-DBa8KF 一个卷组rhel，一个pv是/dev/sda2 [root@rac2 ~]# echo "- - -" > /sys/class/scsi_host/host0/scan [root@rac1 ~]# fdisk -l Disk /dev/sda: 21.5 GB, 21474836480 bytes, 41943040 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk label type: dos Disk identifier: 0x000aa76d Device Boot Start End Blocks Id System /dev/sda1 * 2048 1026047 512000 83 Linux /dev/sda2 1026048 41943039 20458496 8e Linux LVM Disk /dev/sdb: 16.1 GB, 16106127360 bytes, 31457280 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk /dev/mapper/rhel-root: 18.8 GB, 18798870528 bytes, 36716544 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk /dev/mapper/rhel-swap: 2147 MB, 2147483648 bytes, 4194304 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes 在线添加一块16G的硬盘。 [root@rac1 ~]# pvcreate /dev/sdb Physical volume "/dev/sdb" successfully created [root@rac1 ~]# pvdisplay --- Physical volume --- PV Name /dev/sda2 VG Name rhel PV Size 19.51 GiB / not usable 3.00 MiB Allocatable yes (but full) PE Size 4.00 MiB Total PE 4994 Free PE 0 Allocated PE 4994 PV UUID wRff8C-8kkz-0E1N-CKLh-YnBu-7qAf-DBa8KF "/dev/sdb" is a new physical volume of "15.00 GiB" --- NEW Physical volume --- PV Name /dev/sdb VG Name PV Size 15.00 GiB Allocatable NO PE Size 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID XkelY2-zsv3-1Cpu-GRkJ-RmqZ-CKTs-XmHVkR [root@rac1 ~]# pvscan PV /dev/sda2 VG rhel lvm2 [19.51 GiB / 0 free] PV /dev/sdb lvm2 [15.00 GiB] Total: 2 [34.51 GiB] / in use: 1 [19.51 GiB] / in no VG: 1 [15.00 GiB] [root@rac1 ~]# vgextend rhel /dev/sdb Volume group "rhel" successfully extended [root@rac1 ~]# pvdisplay --- Physical volume --- PV Name /dev/sda2 VG Name rhel PV Size 19.51 GiB / not usable 3.00 MiB Allocatable yes (but full) PE Size 4.00 MiB Total PE 4994 Free PE 0 Allocated PE 4994 PV UUID wRff8C-8kkz-0E1N-CKLh-YnBu-7qAf-DBa8KF --- Physical volume --- PV Name /dev/sdb VG Name rhel PV Size 15.00 GiB / not usable 4.00 MiB Allocatable yes PE Size 4.00 MiB Total PE 3839 Free PE 3839 Allocated PE 0 PV UUID XkelY2-zsv3-1Cpu-GRkJ-RmqZ-CKTs-XmHVkR 创建PV，加入VG [root@rac1 ~]# swapoff -v /dev/sdb swapoff /dev/sdb swapoff: /dev/sdb: swapoff failed: Invalid argument [root@rac1 ~]# swapoff -v /dev/rhel/swap swapoff /dev/rhel/swap [root@rac1 ~]# lvresize -L+1.5G /dev/rhel/swap Extending logical volume swap to 3.50 GiB Logical volume swap successfully resized [root@rac1 ~]# mkswap /dev/rhel/swap mkswap: /dev/rhel/swap: warning: wiping old swap signature. Setting up swapspace version 1, size = 3670012 KiB no label, UUID=6323ca9b-e968-4c0e-8852-51aee7c93407 [root@rac1 ~]# swapon /dev/rhel/swap [root@rac1 ~]# free -m total used free shared buffers cached Mem: 1826 937 889 9 0 326 -/+ buffers/cache: 610 1216 Swap: 3583 0 3583 [root@rac1 ~]# swap扩展到3.5G [root@rac1 ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/rhel-root 18G 5.0G 13G 29% / devtmpfs 908M 0 908M 0% /dev tmpfs 914M 164K 914M 1% /dev/shm tmpfs 914M 9.0M 905M 1% /run tmpfs 914M 0 914M 0% /sys/fs/cgroup /dev/sda1 497M 96M 401M 20% /boot /dev/sr0 3.5G 3.5G 0 100% /run/media/root/RHEL-7.0 Server.x86_64 [root@rac1 ~]# lvextend -L +5G /dev/mapper/rhel-root Extending logical volume root to 22.51 GiB Logical volume root successfully resized [root@rac1 ~]# xfs_growfs /dev/rhel/root meta-data=/dev/mapper/rhel-root isize=256 agcount=4, agsize=1147392 blks = sectsz=512 attr=2, projid32bit=1 = crc=0 data = bsize=4096 blocks=4589568, imaxpct=25 = sunit=0 swidth=0 blks naming =version 2 bsize=4096 ascii-ci=0 ftype=0 log =internal bsize=4096 blocks=2560, version=2 = sectsz=512 sunit=0 blks, lazy-count=1 realtime =none extsz=4096 blocks=0, rtextents=0 data blocks changed from 4589568 to 5900288 [root@rac1 ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/rhel-root 23G 5.0G 18G 22% / devtmpfs 908M 0 908M 0% /dev tmpfs 914M 164K 914M 1% /dev/shm tmpfs 914M 9.0M 905M 1% /run tmpfs 914M 0 914M 0% /sys/fs/cgroup /dev/sda1 497M 96M 401M 20% /boot /dev/sr0 3.5G 3.5G 0 100% /run/media/root/RHEL-7.0 Server.x86_64 [root@rac1 ~]# 根目录扩展到23G，大功告成。
