我们租用了一台服务器，该服务器有两个 NVMe 磁盘，采用 raid1 配置，并在其上有一个 lvm。
是否可以在不对 lvm 配置进行任何更改的情况下将 raid 级别更改为 raid0？我们不需要冗余，但可能很快就需要更多磁盘空间。
我没有使用过 mdadm。我尝试运行，mdadm --grow /dev/md4 -l 0但出现错误：mdadm: failed to remove internal bitmap.
一些附加信息：
操作系统是ubuntu 18.04
托管服务提供商，IONOS
我可以访问 Debian 救援系统，但无法物理访问服务器。
mdadm --detail /dev/md4
=======================
/dev/md4:
Version : 1.0
Creation Time : Wed May 12 09:52:01 2021
Raid Level : raid1
Array Size : 898628416 (857.00 GiB 920.20 GB)
Used Dev Size : 898628416 (857.00 GiB 920.20 GB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent
Intent Bitmap : Internal
Update Time : Wed May 12 10:55:07 2021
State : clean, degraded, recovering
Active Devices : 1
Working Devices : 2
Failed Devices : 0
Spare Devices : 1
Consistency Policy : bitmap
Rebuild Status : 7% complete
Name : punix:4
UUID : 42d57123:263dd789:ef368ee1:8e9bbe3f
Events : 991
Number Major Minor RaidDevice State
0 259 9 0 active sync /dev/nvme0n1p4
2 259 4 1 spare rebuilding /dev/nvme1n1p4
/proc/mdstat:
=======
Personalities : [raid1] [linear] [multipath] [raid0] [raid6] [raid5] [raid4] [raid10]
md2 : active raid1 nvme0n1p2[0] nvme1n1p2[2]
29293440 blocks super 1.0 [2/1] [U_]
resync=DELAYED
md4 : active raid1 nvme0n1p4[0] nvme1n1p4[2]
898628416 blocks super 1.0 [2/1] [U_]
[>....................] recovery = 2.8% (25617280/898628416) finish=704.2min speed=20658K/sec
bitmap: 1/7 pages [4KB], 65536KB chunk
unused devices: <none>
df -h:
======
Filesystem Size Used Avail Use% Mounted on
udev 32G 0 32G 0% /dev
tmpfs 6.3G 11M 6.3G 1% /run
/dev/md2 28G 823M 27G 3% /
/dev/vg00/usr 9.8G 1013M 8.3G 11% /usr
tmpfs 32G 0 32G 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 32G 0 32G 0% /sys/fs/cgroup
/dev/mapper/vg00-home 9.8G 37M 9.3G 1% /home
/dev/mapper/vg00-var 9.8G 348M 9.0G 4% /var
tmpfs 6.3G 0 6.3G 0% /run/user/0
fdisk -l:
=========
Disk /dev/nvme1n1: 894.3 GiB, 960197124096 bytes, 1875385008 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
Disklabel type: gpt
Disk identifier: 3FEDFA8D-D63F-42EE-86C9-5E728FA617D2
Device Start End Sectors Size Type
/dev/nvme1n1p1 2048 6143 4096 2M BIOS boot
/dev/nvme1n1p2 6144 58593279 58587136 28G Linux RAID
/dev/nvme1n1p3 58593280 78125055 19531776 9.3G Linux swap
/dev/nvme1n1p4 78125056 1875382271 1797257216 857G Linux RAID
Disk /dev/md4: 857 GiB, 920195497984 bytes, 1797256832 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/md2: 28 GiB, 29996482560 bytes, 58586880 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/nvme0n1: 894.3 GiB, 960197124096 bytes, 1875385008 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
Disklabel type: gpt
Disk identifier: 948B7F9A-0758-4B01-8CD2-BDB08D0BE645
Device Start End Sectors Size Type
/dev/nvme0n1p1 2048 6143 4096 2M BIOS boot
/dev/nvme0n1p2 6144 58593279 58587136 28G Linux RAID
/dev/nvme0n1p3 58593280 78125055 19531776 9.3G Linux swap
/dev/nvme0n1p4 78125056 1875382271 1797257216 857G Linux RAID
Disk /dev/mapper/vg00-usr: 10 GiB, 10737418240 bytes, 20971520 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/vg00-var: 10 GiB, 10737418240 bytes, 20971520 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/vg00-home: 10 GiB, 10737418240 bytes, 20971520 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
lvm configuration:
==================
--- Physical volume ---
PV Name /dev/md4
VG Name vg00
PV Size <857.00 GiB / not usable 2.81 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 219391
Free PE 211711
Allocated PE 7680
PV UUID bdTpM6-vxql-momc-sTZC-0B3R-VFtZ-S72u7V
--- Volume group ---
VG Name vg00
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 4
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 3
Open LV 3
Max PV 0
Cur PV 1
Act PV 1
VG Size <857.00 GiB
PE Size 4.00 MiB
Total PE 219391
Alloc PE / Size 7680 / 30.00 GiB
Free PE / Size 211711 / <827.00 GiB
VG UUID HIO5xT-VRw3-BZN7-3h3m-MGqr-UwOS-WxOQTS
--- Logical volume ---
LV Path /dev/vg00/usr
LV Name usr
VG Name vg00
LV UUID cv3qcf-8ZB4-JaIp-QYvo-x4ol-veIH-xI37Z6
LV Write Access read/write
LV Creation host, time punix, 2021-05-12 09:52:03 +0000
LV Status available
# open 1
LV Size 10.00 GiB
Current LE 2560
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
--- Logical volume ---
LV Path /dev/vg00/var
LV Name var
VG Name vg00
LV UUID ZtAM8T-MO4F-YrqF-hgUN-ctMC-1RSn-crup3E
LV Write Access read/write
LV Creation host, time punix, 2021-05-12 09:52:03 +0000
LV Status available
# open 1
LV Size 10.00 GiB
Current LE 2560
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1
--- Logical volume ---
LV Path /dev/vg00/home
LV Name home
VG Name vg00
LV UUID AeIwpS-dnX1-6oGP-ieZ2-hmGs-57zd-6DnXRv
LV Write Access read/write
LV Creation host, time punix, 2021-05-12 09:52:03 +0000
LV Status available
# open 1
LV Size 10.00 GiB
Current LE 2560
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:2
谢谢
答案1
这可能不是您最初考虑的方法，但您可以在磁盘之间移动 LVM 数据，以便最终将两个驱动器作为卷组中的 LVM 物理卷。
为此，您需要从 RAID1 阵列中移除一个驱动器，pvcreate在分离的驱动器上运行以重新格式化它，然后使用 将其添加到您的 LVM 卷vgextend中。这应该会使您的 LVM 卷组大小翻倍。然后从 LVM VG 中移除降级的阵列，这应该以相当容错的方式传输数据。（pvmove有关详细信息，请参阅手册页中的“注释”部分）。一旦从 VG 中移除了该降级的阵列，您就可以停止该阵列，然后以与添加另一个驱动器相同的方式将剩余的驱动器添加到 LVM 组。
我最近在类似情况下迁移了 LVM 托管数据，但从具有两个数据副本的 RAID10 迁移到两个 RAID1 阵列，每个阵列有三个副本，并且磁盘更大。因此，我们实现了两全其美：更多数据和更高可靠性。我不知道您的用例是什么，但我应该说，除非能够轻松地从头开始重新生成，否则我个人不会愿意在没有 RAID 的情况下托管数据。2 TB 似乎需要重新创建或同步大量数据，但如果没有人会因为长时间停机或网络流量而烦恼，那就由您决定了。