分类： 嵌入式
2013-11-24 22:47:31
扩缩文件系统
一、离线扩展文件系统
二、离线收缩文件系统
三、使用lvresize 进行回缩文件系统
四、在线动态扩展文件系统
五、扩展lv使用vg剩余的所有空间
六、将vg00剩余的所有空间创建为一个lv(yzhqlv)
七、lvextend和lvreduce的小例子说明
测试平台：Red Hat Enterprise Linux Server release 5.2 (Tikanga)
一、离线扩展文件系统
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1. 测试卷/dev/vg00/lv00信息
===========================
[root@rhttt lv00]# lvs
LV VG Attr LSize Origin Snap% Move Log Copy% Convert
lv00 vg00 -wi-ao 52.00M
lv01 vg00 -wi-a- 52.00M
lv02 vg00 -wi-a- 52.00M
[root@rhttt ~]# mount /dev/vg00/lv00 /lv00
[root@rhttt ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 3.6G 2.8G 631M 82% /
/dev/sda1 99M 11M 83M 12% /boot
tmpfs 125M 0 125M 0% /dev/shm
/dev/hdc 2.9G 2.9G 0 100% /mnt
/dev/mapper/vg00-lv00
51M 4.9M 43M 11% /lv00
[root@rhttt ~]#
2. 使用lvextend扩展逻辑卷
==========================
[root@rhttt ~]# umount /lv00
[root@rhttt ~]# lvextend -L +1G /dev/vg00/lv00 /*将逻辑卷lv00加大1G*/
/dev/cdrom: open failed: Read-only file system
Extending logical volume lv00 to 1.05 GB
Logical volume lv00 successfully resized
[root@rhttt ~]#
[root@rhttt ~]# lvdisplay /dev/vg00/lv00
--- Logical volume ---
LV Name /dev/vg00/lv00
VG Name vg00
LV UUID cx0Ipu-lZjk-21pY-uTDz-toxm-sWzF-6AL4Mh
LV Write Access read/write
LV Status available
# open 0
LV Size 1.05 GB
Current LE 269
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
[root@rhttt ~]#
3. 使用resize2fs扩展文件系统
============================
[root@rhttt ~]# resize2fs /dev/vg00/lv00
resize2fs 1.39 (29-May-2006)
Please run 'e2fsck -f /dev/vg00/lv00' first.
[root@rhttt ~]# e2fsck -f /dev/vg00/lv00
e2fsck 1.39 (29-May-2006)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/vg00/lv00: 11/13328 files (9.1% non-contiguous), 6645/53248 blocks
[root@rhttt ~]# resize2fs /dev/vg00/lv00
resize2fs 1.39 (29-May-2006)
Resizing the filesystem on /dev/vg00/lv00 to 1101824 (1k) blocks.
The filesystem on /dev/vg00/lv00 is now 1101824 blocks long.
[root@rhttt ~]#
4. 挂载该逻辑卷
================
[root@rhttt ~]# mount /dev/vg00/lv00 /lv00
[root@rhttt ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 3.6G 2.8G 631M 82% /
/dev/sda1 99M 11M 83M 12% /boot
tmpfs 125M 0 125M 0% /dev/shm
/dev/hdc 2.9G 2.9G 0 100% /mnt
/dev/mapper/vg00-lv00
1.1G 6.3M 996M 1% /lv00
[root@rhttt ~]#
**************************************************************************
二、离线收缩文件系统
#####################
注意：收缩逻辑卷时，收缩后剩余的逻辑卷大小一定不要小于文件系统的大小。
1. 将lv00的文件大小收缩到30M
============================
[root@rhttt ~]# umount /lv00
[root@rhttt ~]# resize2fs /dev/vg00/lv00 30M
resize2fs 1.39 (29-May-2006)
Please run 'e2fsck -f /dev/vg00/lv00' first.
[root@rhttt ~]# e2fsck -f /dev/vg00/lv00
e2fsck 1.39 (29-May-2006)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/vg00/lv00: 13/257040 files (15.4% non-contiguous), 40610/1101824 blocks
[root@rhttt ~]# resize2fs /dev/vg00/lv00 30M
resize2fs 1.39 (29-May-2006)
Resizing the filesystem on /dev/vg00/lv00 to 30720 (1k) blocks.
The filesystem on /dev/vg00/lv00 is now 30720 blocks long.
[root@rhttt ~]#
2. 将逻辑卷lv00缩小1G
=====================
[root@rhttt ~]# lvreduce -L -1G /dev/vg00/lv00
/dev/cdrom: open failed: Read-only file system
WARNING: Reducing active logical volume to 52.00 MB
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce lv00? [y/n]: y
Reducing logical volume lv00 to 52.00 MB
Logical volume lv00 successfully resized
[root@rhttt ~]#
3. 挂载该逻辑卷
================
[root@rhttt ~]# mount /dev/vg00/lv00 /lv00
**************************************************************************
三、使用lvresize 进行回缩文件系统
==================================
lvresize可以扩展和回缩文件系统
这个例子：在文件系统挂载的情况下，逻辑卷的大大于文件系统的大小，且超过10m时，
对逻辑卷进行回缩10m的实验，回缩后，对该逻辑卷进行了remount。
[root@rhttt lv00]# lvresize -L -10m /dev/vg00/lv00
/dev/cdrom: open failed: Read-only file system
Rounding up size to full physical extent 8.00 MB
WARNING: Reducing active and open logical volume to 44.00 MB
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce lv00? [y/n]: y
Reducing logical volume lv00 to 44.00 MB
Logical volume lv00 successfully resized
[root@rhttt lv00]#
[root@rhttt lv00]# mount -o remount /lv00
[root@rhttt lv00]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 3.6G 2.8G 631M 82% /
/dev/sda1 99M 11M 83M 12% /boot
tmpfs 125M 0 125M 0% /dev/shm
/dev/hdc 2.9G 2.9G 0 100% /mnt
/dev/mapper/vg00-lv00
30M 6.4M 22M 23% /lv00
[root@rhttt lv00]#
**************************************************************************
四、在线动态扩展文件系统
########################
例子：在文件系统挂载的情况下操作，先用lvextend对逻辑卷的容量进行增加1G的大小操作，然后再用
resize2fs直接对文件系统进行在线的扩展，扩展后，可以看到文件系统无需重挂载就已经变成了新的大小。
注意：2.6的内核支持resize2fs的在线扩展，但不支持在线回缩。
The resize2fs program will resize ext2 or ext3 file systems. It can be used to enlarge or shrink an unmounted
file system located on device. If the filesystem is mounted, it can be used to expand the size of the mounted
filesystem, assuming the kernel supports on-line resizing. (As of this writing, the Linux 2.6 kernel supports
on-line resize for filesystems mounted using ext3 only.).
以下是操作示例：
[root@rhttt lv00]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 3.6G 2.8G 631M 82% /
/dev/sda1 99M 11M 83M 12% /boot
tmpfs 125M 0 125M 0% /dev/shm
/dev/hdc 2.9G 2.9G 0 100% /mnt
/dev/mapper/vg00-lv00
30M 6.4M 22M 23% /lv00
[root@rhttt lv00]# lvextend -L +1G /dev/vg00/lv00
/dev/cdrom: open failed: Read-only file system
Extending logical volume lv00 to 1.04 GB
Logical volume lv00 successfully resized
[root@rhttt lv00]# resize2fs /dev/vg00/lv00
resize2fs 1.39 (29-May-2006)
Filesystem at /dev/vg00/lv00 is mounted on /lv00; on-line resizing required
Performing an on-line resize of /dev/vg00/lv00 to 1093632 (1k) blocks.
The filesystem on /dev/vg00/lv00 is now 1093632 blocks long.
[root@rhttt lv00]#
[root@rhttt lv00]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 3.6G 2.8G 631M 82% /
/dev/sda1 99M 11M 83M 12% /boot
tmpfs 125M 0 125M 0% /dev/shm
/dev/hdc 2.9G 2.9G 0 100% /mnt
/dev/mapper/vg00-lv00
1.1G 8.0M 997M 1% /lv00
[root@rhttt lv00]#
在线缩文件系统不支持
=====================
[root@rhttt ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 3.6G 2.8G 631M 82% /
/dev/sda1 99M 11M 83M 12% /boot
tmpfs 125M 0 125M 0% /dev/shm
/dev/hdc 2.9G 2.9G 0 100% /mnt
/dev/mapper/vg00-lv00
1.1G 28M 978M 3% /lv00
[root@rhttt ~]# resize2fs /dev/vg00/lv00 300m
resize2fs 1.39 (29-May-2006)
Filesystem at /dev/vg00/lv00 is mounted on /lv00; on-line resizing required
On-line shrinking from 1093632 to 307200 not supported.
[root@rhttt ~]#
[root@rhttt ~]#
(1)卸载文件系统后，回缩逻辑卷文件系统到300m大小
[root@rhttt ~]# umount /lv00
[root@rhttt ~]# resize2fs /dev/vg00/lv00 300m
resize2fs 1.39 (29-May-2006)
Please run 'e2fsck -f /dev/vg00/lv00' first.
[root@rhttt ~]# e2fsck -f /dev/vg00/lv00
e2fsck 1.39 (29-May-2006)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/vg00/lv00: 14/255136 files (14.3% non-contiguous), 60318/1093632 blocks
[root@rhttt ~]# resize2fs /dev/vg00/lv00 300m
resize2fs 1.39 (29-May-2006)
Resizing the filesystem on /dev/vg00/lv00 to 307200 (1k) blocks.
The filesystem on /dev/vg00/lv00 is now 307200 blocks long.
[root@rhttt ~]#
(2) 使用lvreduce减小逻辑卷的大小。
注意：减小后的大小不能小于文件的大小，否则会丢失数据。
[root@rhttt ~]# lvs
LV VG Attr LSize Origin Snap% Move Log Copy% Convert
lv00 vg00 -wi-a- 1.04G
lv01 vg00 -wi-a- 52.00M
lv02 vg00 -wi-a- 52.00M
[root@rhttt ~]# lvreduce -L -600M /dev/vg00/lv00
/dev/cdrom: open failed: Read-only file system
WARNING: Reducing active logical volume to 468.00 MB
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce lv00? [y/n]: y
Reducing logical volume lv00 to 468.00 MB
Logical volume lv00 successfully resized
[root@rhttt ~]# mount /dev/vg00/lv00 /lv00
[root@rhttt ~]#
五、扩展lv使用vg剩余的所有空间
##############################
-l, --extents [+]LogicalExtentsNumber[%{VG|LV|PVS|FREE}]
Extend or set the logical volume size in units of logical
extents. With the + sign the value is added to the actual size
of the logical volume and without it, the value is taken as an
absolute one. The number can also be expressed as a percentage
of the total space in the Volume Group with the suffix %VG, rel-
ative to the existing size of the Logical Volume with the suffix
%LV, of the remaining free space for the specified PhysicalVol-
ume(s) with the suffix %PVS, or as a percentage of the remaining
free space in the Volume Group with the suffix %FREE.
错误的写法：
[root@oradb1 ~]# lvextend -l 100%FREE /dev/vg00/lv06
New size given (57 extents) not larger than existing size (128 extents)
Run `lvextend --help' for more information.
[root@oradb1 ~]#
正确的写法：
[root@oradb1 ~]# lvextend -l +100%FREE /dev/vg00/lv06
Extending logical volume lv06 to 5.78 GB
Logical volume lv06 successfully resized
[root@oradb1 ~]#
正确的写法应为+100%FREE，注意这个加号"+", 同这个不同的是：将vg00剩余的所有空间创建为一个lv，
lvceate 前面不需要加加号，如下一个标题所示：
[root@oradb1 ~]# resize2fs /dev/vg00/lv06
resize2fs 1.39 (29-May-2006)
Filesystem at /dev/vg00/lv06 is mounted on /u01; on-line resizing required
Performing an on-line resize of /dev/vg00/lv06 to 1515520 (4k) blocks.
The filesystem on /dev/vg00/lv06 is now 1515520 blocks long.
[root@oradb1 ~]#
六、将vg00剩余的所有空间创建为一个lv(yzhqlv)
###########################################
-l, --extents LogicalExtentsNumber[%{VG|PVS|FREE}]
Gives the number of logical extents to allocate for the new logical volume. This can also be expressed
as a percentage of the total space in the Volume Group with the suffix %VG, of the remaining free space
in the Volume Group with the suffix %FREE, or of the remaining free space for the specified PhysicalVol-
ume(s) with the suffix %PVS,
[root@rhttt ~]# lvcreate -l 100%FREE -n yzhqlv vg00
Logical volume "yzhqlv" created
[root@rhttt ~]#
可以看到创建完后，vg00没有剩余的PE了.
[root@rhttt ~]# vgdisplay vg00
--- Volume group ---
VG Name vg00
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 26
VG Access read/write
VG Status resizable
MAX LV 256
Cur LV 4
Open LV 1
Max PV 256
Cur PV 2
Act PV 2
VG Size 4.05 GB
PE Size 4.00 MB
Total PE 1036
Alloc PE / Size 1036 / 4.05 GB
Free PE / Size 0 / 0
VG UUID 2IEBLZ-M2pV-Me75-owiW-W3hr-XGEO-n3eYui
[root@rhttt ~]#
**************************************************************************
七、lvextend和lvreduce的小例子说明
###################################
The following command extends the logical volumne /dev/myvg/homevol to 12 gigabytes.
# lvextend -L12G /dev/myvg/homevol
lvextend -- extending logical volume "/dev/myvg/homevol" to 12 GB
lvextend -- doing automatic backup of volume group "myvg"
lvextend -- logical volume "/dev/myvg/homevol" successfully extended
The following command adds another gigabyte to the logical volume /dev/myvg/homevol.
# lvextend -L+1G /dev/myvg/homevol
lvextend -- extending logical volume "/dev/myvg/homevol" to 13 GB
lvextend -- doing automatic backup of volume group "myvg"
lvextend -- logical volume "/dev/myvg/homevol" successfully extended
As with the lvcreate command, you can use the -l argument of the lvextend command to specify
the number of extents by which to increase the size of the logical volume. You can also use
this argument to specify a percentage of the volume group, or a percentage of the remaining
free space in the volume group. The following command extends the logical volume called
Growing Logical Volumes testlv to fill all of the unallocated space in the volume group myvg.
[root@tng3-1 ~]# lvextend -l +100%FREE /dev/myvg/testlv
Extending logical volume testlv to 68.59 GB
Logical volume testlv successfully resized
After you have extended the logical volume it is necessary to increase the file system size to match.
By default, most file system resizing tools will increase the size of the file system to be the size
of the underlying logical volume so you do not need to worry about specifying the same size for
each of the two commands.
"lvextend -L +54 /dev/vg01/lvol10 /dev/sdk3" tries to extend the size of that logical volume by 54MB on physi-
cal volume /dev/sdk3. This is only possible if /dev/sdk3 is a member of volume group vg01 and there are enough
free physical extents in it.
"lvextend /dev/vg01/lvol01 /dev/sdk3" tries to extend the size of that logical volume by the amount of free
space on physical volume /dev/sdk3. This is equivalent to specifying "-l +100%PVS" on the command line.
"lvreduce -l -3 vg00/lvol1" reduces the size of logical volume lvol1 in volume group vg00 by 3 logical extents.