[linux-lvm] Raid 10 - recovery after a disk failure
emmanuel segura
emi2fast at gmail.com
Sun Jan 31 23:23:07 UTC 2016
You used pvcreate without the required options to create the physical
in your new disk and set the old uuid
example:
pvcreate --uuid "FmGRh3-zhok-iVI8-7qTD-S5BI-MAEN-NYM5Sk" --restorefile
/etc/lvm/archive/VG_00050.vg /dev/sdh1
https://www.centos.org/docs/5/html/Cluster_Logical_Volume_Manager/mdatarecover.html
2016-02-01 0:00 GMT+01:00 Pavlik Kirilov <pavllik at yahoo.ca>:
> Hi,
>
> I am encountering strange behaviour when trying to recover a Raid 10 LV, created with the following command:
>
>
> lvcreate --type raid10 -L3G -i 2 -I 256 -n lv_r10 vg_data /dev/vdb1:1-500 /dev/vdc1:1-500 /dev/vdd1:1-500 /dev/vde1:1-500
>
> As it can be seen, I have 4 PVs and give the first 500 PE of each of them for the raid 10 logical volume. I am able to see the following PE layout:
>
> lvs -o seg_pe_ranges,lv_name,stripes -a
>
> PE Ranges LV #Str
> lv_r10_rimage_0:0-767 lv_r10_rimage_1:0-767 lv_r10_rimage_2:0-767 lv_r10_rimage_3:0-767 lv_r10 4
> /dev/vdb1:2-385 [lv_r10_rimage_0] 1
> /dev/vdc1:2-385 [lv_r10_rimage_1] 1
> /dev/vdd1:2-385 [lv_r10_rimage_2] 1
> /dev/vde1:2-385 [lv_r10_rimage_3] 1
> /dev/vdb1:1-1 [lv_r10_rmeta_0] 1
> /dev/vdc1:1-1 [lv_r10_rmeta_1] 1
> /dev/vdd1:1-1 [lv_r10_rmeta_2] 1
> /dev/vde1:1-1 [lv_r10_rmeta_3] 1
>
>
> So far everything is OK and the number of PE is automatically reduced to 385 per PV to have the size equal to 3 Gigabytes.
>
> The problem comes when I shut down the system, replace one disk (vdc), boot again and try to recover the array. Here are the commands I execute:
> pvs
> Couldn't find device with uuid 2hU2pD-xNDa-yi1J-OkkP-NjGq-hIxo-Q5AgQC.
> PV VG Fmt Attr PSize PFree
> /dev/vdb1 vg_data lvm2 a-- 8.00g 6.49g
> /dev/vdd1 vg_data lvm2 a-- 8.00g 6.49g
> /dev/vde1 vg_data lvm2 a-- 8.00g 6.49g
> unknown device vg_data lvm2 a-m 8.00g 6.49g
>
> pvcreate /dev/vdc1
> Physical volume "/dev/vdc1" successfully created
>
> vgextend vg_data /dev/vdc1
> Couldn't find device with uuid 2hU2pD-xNDa-yi1J-OkkP-NjGq-hIxo-Q5AgQC
> Volume group "vg_data" successfully extended
>
> lvs -o seg_pe_ranges,lv_name,stripes -a
> Couldn't find device with uuid 2hU2pD-xNDa-yi1J-OkkP-NjGq-hIxo-Q5AgQC.
> PE Ranges LV #Str
> lv_r10_rimage_0:0-767 lv_r10_rimage_1:0-767 lv_r10_rimage_2:0-767 lv_r10_rimage_3:0-767 lv_r10 4
> /dev/vdb1:2-385 [lv_r10_rimage_0] 1
> unknown device:2-385 [lv_r10_rimage_1] 1
> /dev/vdd1:2-385 [lv_r10_rimage_2] 1
> /dev/vde1:2-385 [lv_r10_rimage_3] 1
> /dev/vdb1:1-1 [lv_r10_rmeta_0] 1
> unknown device:1-1 [lv_r10_rmeta_1] 1
> /dev/vdd1:1-1 [lv_r10_rmeta_2] 1
> /dev/vde1:1-1 [lv_r10_rmeta_3] 1
>
> lvchange -ay --partial /dev/vg_data/lv_r10
> PARTIAL MODE. Incomplete logical volumes will be processed.
> Couldn't find device with uuid 2hU2pD-xNDa-yi1J-OkkP-NjGq-hIxo-Q5AgQC
>
> lvconvert --repair vg_data/lv_r10 /dev/vdc1:1-385
> Attempt to replace failed RAID images (requires full device resync)? [y/n]: y
> Insufficient free space: 770 extents needed, but only 345 available
> Failed to allocate replacement images for vg_data/lv_r10
>
> lvconvert --repair vg_data/lv_r10
> Attempt to replace failed RAID images (requires full device resync)? [y/n]: y
> Faulty devices in vg_data/lv_r10 successfully replaced.
>
> lvs -o seg_pe_ranges,lv_name,stripes -a
> Couldn't find device with uuid
> 2hU2pD-xNDa-yi1J-OkkP-NjGq-hIxo-Q5AgQC.
>
> PE Ranges LV #Str
> lv_r10_rimage_0:0-767 lv_r10_rimage_1:0-767 lv_r10_rimage_2:0-767 lv_r10_rimage_3:0-767 lv_r10 4
> /dev/vdb1:2-385 [lv_r10_rimage_0] 1
> /dev/vdc1:1-768 [lv_r10_rimage_1] 1
> /dev/vdd1:2-385 [lv_r10_rimage_2] 1
> /dev/vde1:2-385 [lv_r10_rimage_3] 1
> /dev/vdb1:1-1 [lv_r10_rmeta_0] 1
> /dev/vdc1:0-0 [lv_r10_rmeta_1] 1
> /dev/vdd1:1-1 [lv_r10_rmeta_2] 1
> /dev/vde1:1-1 [lv_r10_rmeta_3] 1
>
> The array was recovered, but it is definitely not what I expected, because on /dev/vdc1 now 768 PEs are used instead of 385, like on the other PVs. In this case I had some extra free space on /dev/vdc1, but what if I did not? Please, suggest what should be done.
>
> Linux ubuntu1 3.13.0-32-generic, x86_64
> LVM version: 2.02.98(2) (2012-10-15)
> Library version: 1.02.77 (2012-10-15)
> Driver version: 4.27.0
>
> Pavlik Petrov
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm at redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
--
.~.
/V\
// \\
/( )\
^`~'^
More information about the linux-lvm
mailing list