尝试添加磁盘以镜像CentOS 7上的LVM卷总是失败,“可用空间不足：需要1个扩展区,但只有0个可用”.在搜索了解决方案之后,我尝试了指定磁盘,多个日志记录选项,添加第3个日志分区,但还没有找到解决方案
不确定我是否犯了一个新手错误,或者有更微妙的错误(我更熟悉ZFS,使用LVM的新手)：
# lvconvert -m1 centos_bi/home Insufficient free space: 1 extents needed,but only 0 available # lvconvert -m1 --corelog centos_bi/home Insufficient free space: 1 extents needed,but only 0 available # lvconvert -m1 --corelog --alloc anywhere centos_bi/home Insufficient free space: 1 extents needed,but only 0 available # lvconvert -m1 --mirrorlog mirrored --alloc anywhere centos_bi/home /dev/sda2 Insufficient free space: 1 extents needed,but only 0 available # lvconvert -m1 --corelog --alloc anywhere centos_bi/home /dev/sdi2 /dev/sda2 Insufficient free space: 1 extents needed,but only 0 available
这两个磁盘大小相同,并且通过“sfdisk -d / dev / sdi> part_table; sfdisk / dev / sda< part_table”具有相同的分区布局.目前的配置详述如下.
# pvs PV VG Fmt Attr PSize PFree /dev/sda1 centos_bi lvm2 a-- 496.00m 496.00m /dev/sda2 centos_bi lvm2 a-- 465.27g 465.27g /dev/sdi2 centos_bi lvm2 a-- 465.27g 0 # vgs VG #PV #LV #SN Attr VSize VFree centos_bi 3 3 0 wz--n- 931.02g 465.75g # lvs -a -o +devices LV VG Attr LSize Pool Origin Data% Move Log Cpy%Sync Convert Devices home centos_bi -wi-ao---- 391.64g /dev/sdi2(6050) root centos_bi -wi-ao---- 50.00g /dev/sdi2(106309) swap centos_bi -wi-ao---- 23.63g /dev/sdi2(0) # pvdisplay --- Physical volume --- PV Name /dev/sdi2 VG Name centos_bi PV Size 465.27 GiB / not usable 3.00 MiB Allocatable yes (but full) PE Size 4.00 MiB Total PE 119109 Free PE 0 Allocated PE 119109 --- Physical volume --- PV Name /dev/sda2 VG Name centos_bi PV Size 465.27 GiB / not usable 3.00 MiB Allocatable yes PE Size 4.00 MiB Total PE 119109 Free PE 119109 Allocated PE 0 --- Physical volume --- PV Name /dev/sda1 VG Name centos_bi PV Size 500.00 MiB / not usable 4.00 MiB Allocatable yes PE Size 4.00 MiB Total PE 124 Free PE 124 Allocated PE 0 # vgdisplay --- Volume group --- VG Name centos_bi System ID Format lvm2 Metadata Areas 3 Metadata Sequence No 10 VG Access read/write VG Status resizable MAX LV 0 Cur LV 3 Open LV 3 Max PV 0 Cur PV 3 Act PV 3 VG Size 931.02 GiB PE Size 4.00 MiB Total PE 238342 Alloc PE / Size 119109 / 465.27 GiB Free PE / Size 119233 / 465.75 GiB # lvdisplay --- Logical volume --- LV Path /dev/centos_bi/swap LV Name swap VG Name centos_bi LV Write Access read/write LV Creation host,time localhost,2014-08-07 16:34:34 -0400 LV Status available # open 2 LV Size 23.63 GiB Current LE 6050 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:1 --- Logical volume --- LV Path /dev/centos_bi/home LV Name home VG Name centos_bi LV Write Access read/write LV Creation host,2014-08-07 16:34:35 -0400 LV Status available # open 1 LV Size 391.64 GiB Current LE 100259 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:2 --- Logical volume --- LV Path /dev/centos_bi/root LV Name root VG Name centos_bi LV Write Access read/write LV Creation host,2014-08-07 16:34:37 -0400 LV Status available # open 1 LV Size 50.00 GiB Current LE 12800 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:0
解决方法
从2013年9月左右开始,lvm2中的默认镜像段类型为’raid1′(不是’镜像’).这使得–corelog和–mirrorlog磁盘/核心/镜像选项在此默认情况下不适用,因为raid1段类型始终将其日志(实际上是元数据子卷)存储在与LV相同的PV上的磁盘上镜像.您不再需要第三个PV用于日志,或将日志存储在内存中.
还有两个含义.首先,简化了创建镜像的命令,因为只需要指定要镜像的LV,以及将存储镜像段的(通常是一个)PV：#lvconvert -m1 / dev / my_vg / my_lv / dev / my_new_pv
其次,有几个空间考虑因素.你需要：
>显然,镜子PV上的空间存放了原始LV的副本,
>还要在镜子PV上增加1个LE来存储日志,
>并且(这是我错过了一段时间的点),原始PV上的1个额外LE,用于存储日志(因为日志存储在原始PV和新PV上).
通常这种原始PV附加空间要求会导致问题,因为即使为日志分配了1个新LE,现有PV中也没有空间.在这种情况下,您可能会遇到OP遇到的错误,即需要1个扩展区,但只有0个可用.
如上所述,补救措施是在现有LV上调整大小(缩小文件系统后缩小),因此可以在同一PV上分配日志.如果你不能这样做,你可以使用–type mirror来强制传统的’镜像’段类型.
