[linux-lvm] Recreating logical volume

[Robert Brockway]

Hi all.  I have a RH AS 4 box with 4 H/W RAID array (sdb, sdc, sdd & sde).

All 4 raid arrays were in a single volume group (vg0) which was then made 
in to a single logical volume (lv0).  Both sdb & sdd are now 
uncontactable (they don't even appear in fdisk).

I umounted the filesystem (/data) originally with the intend of running 
e2fsck on the filesystem (it's ext3).  This failed and I attempted to 
remoun the filesystem but was unable to.

I used vgreduce --test --removemissing vg0 and as it looked good I went 
ahead and used vgreduce --removemissing vg0

Of course this has removed lv0.

If I use lvcreate -Zn on the remaining PVs: sdc & sde can I recover the 
logical volume and then go on to mount /data again?

Here is some data:

$sudo pvdisplay
Password:
   /dev/sdb: read failed after 0 of 4096 at 0: Input/output error
   /dev/sdb1: read failed after 0 of 2048 at 0: Input/output error
   /dev/sdd: read failed after 0 of 4096 at 0: Input/output error
   /dev/sdd1: read failed after 0 of 2048 at 0: Input/output error
   --- Physical volume ---
   PV Name               /dev/sdc1
   VG Name               vg0
   PV Size               1.64 TB / not usable 0
   Allocatable           yes
   PE Size (KByte)       4096
   Total PE              429149
   Free PE               429149
   Allocated PE          0
   PV UUID               i0kyjz-8U3i-fMCT-Trxs-vF7W-wnap-M4fBlP

   --- Physical volume ---
   PV Name               /dev/sde1
   VG Name               vg0
   PV Size               1.64 TB / not usable 0
   Allocatable           yes
   PE Size (KByte)       4096
   Total PE              429149
   Free PE               429149
   Allocated PE          0
   PV UUID               YR2tx7-PLFu-xAGJ-d4KP-RIW9-Nguh-KzjybH

$sudo vgdisplay
   /dev/sdb: read failed after 0 of 4096 at 0: Input/output error
   /dev/sdb1: read failed after 0 of 2048 at 0: Input/output error
   /dev/sdd: read failed after 0 of 4096 at 0: Input/output error
   /dev/sdd1: read failed after 0 of 2048 at 0: Input/output error
   --- Volume group ---
   VG Name               vg0
   System ID
   Format                lvm2
   Metadata Areas        2
   Metadata Sequence No  8
   VG Access             read/write
   VG Status             resizable
   MAX LV                256
   Cur LV                0
   Open LV               0
   Max PV                256
   Cur PV                2
   Act PV                2
   VG Size               3.27 TB
   PE Size               4.00 MB
   Total PE              858298
   Alloc PE / Size       0 / 0
   Free  PE / Size       858298 / 3.27 TB
   VG UUID               0MT3nn-xqM1-6ScL-XEM3-1Kyo-XDOp-SkhV8R


Thanks,

Rob

-- 
Robert Brockway B.Sc. email: robert.brockway at utoronto.ca
                       phone: +1-416-978-1829
Snr System Administrator, Linux & HPC, CCBR, University of Toronto
Contributing member of Software in the Public Interest