使用 LVM 安装 Ubuntu，新加一块硬盘， LV 放大成功， LV 挂载的目录容量并没有增加，请问还需如何操作或者有哪里做错了？

我创建了 2 个 VG，一个 ubuntu 在 SSD 上，挂载除了 /var 以外的文件；一个 var 在 HDD 上，专门挂载 /var 目录。
因为现在 SSD 太贵了，用了一个拆机的 SSD，担心系统会挂掉，HDD 里的 /var 数据依然在，不知道我这样的想法对不对？（准备做 NAS 用，系统尝试是在虚拟机里试验的）
我在虚拟机里尝试加了一块硬盘，通过 vgextend 加大 VG var 的容量，然后给 lv-var 扩容，现在显示扩容也成功了，可是 /var 文件夹依然是 20G 的容量，请问还需如何操作？

root@virtual-machine:~# vgdisplay
--- Volume group ---
VG Name var
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 4
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 1
Open LV 1
Max PV 0
Cur PV 2
Act PV 2
VG Size 39.99 GiB
PE Size 4.00 MiB
Total PE 10238
Alloc PE / Size 10238 / 39.99 GiB
Free PE / Size 0 / 0

root@virtual-machine:~# lvdisplay
--- Logical volume ---
LV Path /dev/var/lv-var
LV Name lv-var
VG Name var
LV UUID 7HLbWK-hZ8B-wY09-Mh3w-XGrD-Ttf1-ayQGQy
LV Write Access read/write
LV Creation host, time ubuntu, 2017-09-11 19:54:35 +0800
LV Status available
# open 1
LV Size 39.99 GiB
Current LE 10238
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0

root@virtual-machine:~# resize2fs /dev/var/lv-var
resize2fs 1.43.4 (31-Jan-2017)
resize2fs: 超级块中的幻数有错尝试打开 /dev/var/lv-var 时
找不到有效的文件系统超级块。

nightma7e

2017-09-14 22:27:06 +08:00

@bearice
root@virtual-machine:/home/zm# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 20G 0 disk
├─sda1 8:1 0 1G 0 part /boot
└─sda2 8:2 0 19G 0 part
├─ubuntu-lv--swap 253:1 0 4G 0 lvm [SWAP]
├─ubuntu-lv--root 253:2 0 10G 0 lvm /
└─ubuntu-lv--home 253:3 0 4.5G 0 lvm /home
sdb 8:16 0 20G 0 disk
└─sdb1 8:17 0 20G 0 part
└─var-lv--var 253:0 0 40G 0 lvm /var
sdc 8:32 0 20G 0 disk
└─sdc1 8:33 0 20G 0 part
└─var-lv--var 253:0 0 40G 0 lvm /var
sr0 11:0 1 1.5G 0 rom /media/zm/Ubuntu 17.04 amd64

root@virtual-machine:/home/zm# blkid
/dev/sda1: UUID="2467ce51-5cc0-4567-9a7c-ca888762f295" TYPE="xfs" PARTUUID="50a863db-b28f-450b-a84a-c00d1448f665"
/dev/sda2: UUID="zFuMT6-KKvU-eJsV-rNpi-M18f-Nbgy-Pe0Ogr" TYPE="LVM2_member" PARTUUID="0b423e04-865c-483e-8e46-ce694064fb58"
/dev/sdb1: UUID="WsMCrh-pfag-SxfD-khCn-rGn8-IodH-vL4AEL" TYPE="LVM2_member" PARTUUID="abe98667-3761-4598-8fb2-d46040b42d7d"
/dev/sdc1: UUID="W8DTLM-u0e4-3NQv-uVJ8-k8Qy-bkfS-2CiaXj" TYPE="LVM2_member" PARTUUID="8644e646-93da-4cff-879b-ca87515a0ddf"
/dev/sr0: UUID="2017-04-12-03-44-04-00" LABEL="Ubuntu 17.04 amd64" TYPE="iso9660" PTUUID="1b571474" PTTYPE="dos"
/dev/mapper/var-lv--var: UUID="3e13880c-b2fa-44e8-83a4-668ccebe8e41" TYPE="xfs"
/dev/mapper/ubuntu-lv--swap: UUID="eb94dd27-170f-4fed-9f8f-a6e883360b42" TYPE="swap"
/dev/mapper/ubuntu-lv--root: UUID="dfe45c06-4d2b-4414-89f3-0ec4052ca26b" TYPE="xfs"
/dev/mapper/ubuntu-lv--home: UUID="04ce657a-9935-4851-b150-a529780d474d" TYPE="xfs"

root@virtual-machine:/home/zm# mount
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
udev on /dev type devtmpfs (rw,nosuid,relatime,size=990476k,nr_inodes=247619,mode=755)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)
tmpfs on /run type tmpfs (rw,nosuid,noexec,relatime,size=202708k,mode=755)
/dev/mapper/ubuntu-lv--root on / type xfs (rw,relatime,attr2,inode64,noquota)
securityfs on /sys/kernel/security type securityfs (rw,nosuid,nodev,noexec,relatime)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
tmpfs on /run/lock type tmpfs (rw,nosuid,nodev,noexec,relatime,size=5120k)
tmpfs on /sys/fs/cgroup type tmpfs (ro,nosuid,nodev,noexec,mode=755)
cgroup on /sys/fs/cgroup/systemd type cgroup (rw,nosuid,nodev,noexec,relatime,xattr,release_agent=/lib/systemd/systemd-cgroups-agent,name=systemd)
pstore on /sys/fs/pstore type pstore (rw,nosuid,nodev,noexec,relatime)
cgroup on /sys/fs/cgroup/devices type cgroup (rw,nosuid,nodev,noexec,relatime,devices)
cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset)
cgroup on /sys/fs/cgroup/pids type cgroup (rw,nosuid,nodev,noexec,relatime,pids)
cgroup on /sys/fs/cgroup/freezer type cgroup (rw,nosuid,nodev,noexec,relatime,freezer)
cgroup on /sys/fs/cgroup/perf_event type cgroup (rw,nosuid,nodev,noexec,relatime,perf_event)
cgroup on /sys/fs/cgroup/hugetlb type cgroup (rw,nosuid,nodev,noexec,relatime,hugetlb)
cgroup on /sys/fs/cgroup/net_cls,net_prio type cgroup (rw,nosuid,nodev,noexec,relatime,net_cls,net_prio)
cgroup on /sys/fs/cgroup/blkio type cgroup (rw,nosuid,nodev,noexec,relatime,blkio)
cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (rw,nosuid,nodev,noexec,relatime,cpu,cpuacct)
cgroup on /sys/fs/cgroup/memory type cgroup (rw,nosuid,nodev,noexec,relatime,memory)
systemd-1 on /proc/sys/fs/binfmt_misc type autofs (rw,relatime,fd=36,pgrp=1,timeout=0,minproto=5,maxproto=5,direct,pipe_ino=17701)
debugfs on /sys/kernel/debug type debugfs (rw,relatime)
mqueue on /dev/mqueue type mqueue (rw,relatime)
hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime)
fusectl on /sys/fs/fuse/connections type fusectl (rw,relatime)
/dev/mapper/var-lv--var on /var type xfs (rw,relatime,attr2,inode64,noquota)
/dev/mapper/ubuntu-lv--home on /home type xfs (rw,relatime,attr2,inode64,noquota)
/dev/sda1 on /boot type xfs (rw,relatime,attr2,inode64,noquota)
tmpfs on /run/user/1000 type tmpfs (rw,nosuid,nodev,relatime,size=202704k,mode=700,uid=1000,gid=1000)
gvfsd-fuse on /run/user/1000/gvfs type fuse.gvfsd-fuse (rw,nosuid,nodev,relatime,user_id=1000,group_id=1000)
/dev/sr0 on /media/zm/Ubuntu 17.04 amd64 type iso9660 (ro,nosuid,nodev,relatime,uid=1000,gid=1000,iocharset=utf8,mode=0400,dmode=0500,uhelper=udisks2)
tmpfs on /run/user/0 type tmpfs (rw,nosuid,nodev,relatime,size=202704k,mode=700)