With newer XenServer Version (> 5.x) you cannot longer use the old EXT3 based local storage repositories to store your virtual disks. Citrix has introduced LVM based storage repositories instead.
Caution: Make a backup before executing the following steps, otherwise you’ll lose all your data on the disk!
I assume, we already have a configured RAID1 mirror with a XSLocalEXT storage repository due to a XenServer upgrade. If you want to create a new software mirror with two new installed local disks, you have to create a new md-device with mdadm (this is not part of this documentation).
First, identify the status and devices of the mirror
If the RAID is in “rebuild” status, wait until it’s in “active” status.
[root@xenserver ~]# cat /proc/mdstat Personalities : [raid1] md126 : active raid1 sda[1] sdb[0] 488383488 blocks super external:/md127/0 [2/2] [UU] md127 : inactive sdb[1](S) sda[0](S) 5928 blocks super external:imsm unused devices: <none>
Get more details about the Software Mirror
mdadm --detail /dev/md126 mdadm --examine --brief --scan --config=partitions
Identify and remove old logical volume from RAID1
[root@xenserver ~]# lvscan ACTIVE '/dev/VG_XenStorage-04cd13e0-8237-7754-2d66-4a6a10c5137e/MGT' [4.00 MiB] inherit ACTIVE '/dev/VG_XenStorage-04cd13e0-8237-7754-2d66-4a6a10c5137e/VHD-9ac571bf-5809-4f1e-a767-9fcb0c1d0b88' [19.57 GiB] inherit ACTIVE '/dev/VG_XenStorage-04cd13e0-8237-7754-2d66-4a6a10c5137e/VHD-a5b9ff3b-3bf2-4ea8-a53b-7fc086f4b4ab' [80.16 GiB] inherit ACTIVE '/dev/VG_XenStorage-04cd13e0-8237-7754-2d66-4a6a10c5137e/VHD-186f9092-9d98-410c-8839-024172512a36' [78.31 GiB] inherit ACTIVE '/dev/VG_XenStorage-04cd13e0-8237-7754-2d66-4a6a10c5137e/VHD-6fb6374a-1b83-48c6-bd26-277f19dcf4a8' [34.78 GiB] inherit inactive '/dev/VG_XenStorage-04cd13e0-8237-7754-2d66-4a6a10c5137e/VHD-940e675e-aa13-4aa1-b694-41b6516b7e28' [48.93 GiB] inherit inactive '/dev/VG_XenStorage-04cd13e0-8237-7754-2d66-4a6a10c5137e/VHD-60d3bd98-f81d-412b-86f6-d1d65ae6c7d2' [34.78 GiB] inherit ACTIVE '/dev/VG_XenStorage-04cd13e0-8237-7754-2d66-4a6a10c5137e/VHD-ac10a162-e39e-4e61-a40c-3221413da002' [65.13 GiB] inherit inactive '/dev/XSLocalEXT-6123fd9a-b126-2b74-a476-5a120175a1d9/6123fd9a-b126-2b74-a476-5a120175a1d9' [465.75 GiB] inherit
We want to remove the device /dev/XSLocalEXT …
First deactivate the LV if not already done
[root@xenserver ~]# lvchange -a n /dev/XSLocalEXT-6123fd9a-b126-2b74-a476-5a120175a1d9/6123fd9a-b126-2b74-a476-5a120175a1d9
Now you can remove the LV. You must add the metadata_read_only option, because Xenserver sets a read-only flag.
lvremove /dev/XSLocalEXT-6123fd9a-b126-2b74-a476-5a120175a1d9/6123fd9a-b126-2b74-a476-5a120175a1d9 --config global{metadata_read_only=0}
Remove also the empty volume group
[root@xenserver ~]# vgs
VG #PV #LV #SN Attr VSize VFree
VG_XenStorage-04cd13e0-8237-7754-2d66-4a6a10c5137e 1 8 0 wz--n- 890.00g 528.33g
XSLocalEXT-6123fd9a-b126-2b74-a476-5a120175a1d9 1 0 0 wz--n- 465.75g 465.75g
vgremove XSLocalEXT-6123fd9a-b126-2b74-a476-5a120175a1d9 --config global{metadata_read_only=0}
Check also, that the physical volume has no more corresponding logical volume
[root@xenserver ~]# pvscan PV /dev/sdd3 VG XSLocalEXT-fa330a8c-3f42-42f5-9935-3e4b40c03be3 lvm2 [457.75 GiB / 0 free] PV /dev/sdc3 VG VG_XenStorage-04cd13e0-8237-7754-2d66-4a6a10c5137e lvm2 [890.00 GiB / 528.33 GiB free] PV /dev/md126p1 lvm2 [465.76 GiB] Total: 3 [1.77 TiB] / in use: 2 [1.32 TiB] / in no VG: 1 [465.76 GiB] [root@xenserver ~]# pvs PV VG Fmt Attr PSize PFree /dev/md126p1 lvm2 --- 465.76g 465.76g /dev/sdc3 VG_XenStorage-04cd13e0-8237-7754-2d66-4a6a10c5137e lvm2 a-- 890.00g 528.33g /dev/sdd3 XSLocalEXT-fa330a8c-3f42-42f5-9935-3e4b40c03be3 lvm2 a-- 457.75g 0
Reusing the local RAID1 by creating a new local storage repository with type=lvm
First, identify the MD-Partition with it’s uuid
ll /dev/disk/by-id/ lrwxrwxrwx 1 root root 13 Dec 29 09:26 md-uuid-27052c74:af76a037:e50f003e:65d1ffb8-part1 -> ../../md126p1
Then create the new LVM based storage repository
xe sr-create type=lvm content-type=user device-config:device=/dev/disk/by-id/md-uuid-27052c74:af76a037:e50f003e:65d1ffb8-part1 name-label="Local Disk RAID1"
Check, that the SR was successfully created
[root@xenserver ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 465.8G 0 disk
└─md126 9:126 0 465.8G 0 raid1
└─md126p1 259:0 0 465.8G 0 md
└─VG_XenStorage--d5e61586--e747--dac1--f971--29281873a18c-MGT 253:2 0 4M 0 lvm
sdb 8:16 0 465.8G 0 disk
└─md126 9:126 0 465.8G 0 raid1
└─md126p1 259:0 0 465.8G 0 md
└─VG_XenStorage--d5e61586--e747--dac1--f971--29281873a18c-MGT 253:2 0 4M 0 lvm
You can now use the new created SR in Xencenter to store your VMs.