使用活動 lvm 將 mdadm raid 從 raid1 增加到 raid0

我們在 raid1 配置中租用了一個帶有兩個 NVMe 磁碟的伺服器，上面還有一個 lvm。

是否可以在不對 lvm 配置進行任何更改的情況下將 RAID 級別更改為 raid0？我們不需要冗餘，但很快可能需要更多磁碟空間。

我沒有使用 mdadm 的經驗。我嘗試執行mdadm --grow /dev/md4 -l 0但出現錯誤：mdadm: failed to remove internal bitmap.

一些附加資訊：

作業系統是ubuntu 18.04

託管服務提供商，IONOS

我可以訪問 debian 救援系統，但無法物理訪問伺服器。

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
  

謝謝

這可能不是您最初考慮的方法，但您可以在磁碟之間移動 LVM 數據，以便最終將兩個驅動器作為卷組中的 LVM 物理卷。

為此，您將從 RAID1 陣列中刪除一個驅動器，pvcreate在分離的驅動器上執行以重新格式化它，然後將其添加到您的 LVM 卷中vgextend。這應該使您的 LVM 卷組大小加倍。然後從 LVM VG 中刪除降級的陣列，它應該以相當容錯的方式傳輸數據。pvmove（有關詳細資訊，請參閱手冊頁中的“註釋”部分）。從 VG 中刪除降級的陣列後，您可以停止陣列，然後將剩餘的驅動器添加到 LVM 組，方法與添加另一個驅動器的方式相同。

我最近在類似的場景中遷移了 LVM 託管數據，但從具有兩個數據副本的 RAID10 遷移到每個陣列三個副本的兩個 RAID1 陣列，並且具有更大的磁碟。所以我們得到了兩全其美：更多的數據和更高的可靠性。我不知道您的案例是什麼，但我應該提一下，如果沒有 RAID，我個人不會對託管數據感到滿意，除非它很容易從頭開始重新生成。2 TB 似乎需要重新創建或同步大量數據，但如果沒有人會被延長的停機時間或網路流量所困擾，那就由您來決定。

引用自：https://serverfault.com/questions/1063322