Hi there, My server recently got a (short) holiday from the data centre it's been locked in for a few years and a fresh OS install which brought it up to CentOS 5.2. The installation was slightly hurried and the LVM setup was not reviewed very thoroughly - the default CentOS installer partitions were simply accepted. The server has two Maxtor 200 GB disks which were previously configured to run in a RAID-1 configuration. However, judging by the output of fdisk -l, mount, pvdisplay and lvdisplay, it seems that while the system is using /dev/sda1 as /boot, it's using /dev/sdb2 as the / partition. Running system-config-lvm shows /dev/sda2 as uninitialised. Running pvdisplay results in the following: # pvdisplay Found duplicate PV g7ZWtzNQcHx2PMQghP0NBHDXuYcaYqAt: using /dev/sdb2 not /dev/sda2 --- Physical volume --- PV Name /dev/sdb2 VG Name VolGroup00 PV Size 189.67 GB / not usable 15.34 MB Allocatable yes (but full) PE Size (KByte) 32768 Total PE 6069 Free PE 0 Allocated PE 6069 PV UUID g7ZWtz-NQcH-x2PM-QghP-0NBH-DXuY-caYqAt I'm not running EMC PowerPath as suggested in KB article http://kbase.redhat.com/faq/FAQ_80_12135.shtm. Some other config details are included below for information and hopefully to help someone to spot the problem I'm having. Could this be caused by the RAID superblock being preserved on the disks despite the OS being reinstalled? Ideally I would like to configure the system to run with redundancy - either using software RAID-1 or using LVM mirroring, the investigation of which is what led me to discover this problem in the first place. Best wishes Michael --------------------------------------------------------------------------------------------------- # lvdisplay Found duplicate PV g7ZWtzNQcHx2PMQghP0NBHDXuYcaYqAt: using /dev/sdb2 not /dev/sda2 --- Logical volume --- LV Name /dev/VolGroup00/LogVol00 VG Name VolGroup00 LV UUID rvPZJS-6Z7a-kXzk-aLcM-vv13-eRCK-kjg6I1 LV Write Access read/write LV Status available # open 1 LV Size 187.72 GB Current LE 6007 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:0 --- Logical volume --- LV Name /dev/VolGroup00/LogVol01 VG Name VolGroup00 LV UUID zvxDsa-MZXn-akSA-DlzC-49IX-65Fo-HPBuyJ LV Write Access read/write LV Status available # open 1 LV Size 1.94 GB Current LE 62 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:1 --------------------------------------------------------------------------------------------------- # vgdisplay Found duplicate PV g7ZWtzNQcHx2PMQghP0NBHDXuYcaYqAt: using /dev/sdb2 not /dev/sda2 --- Volume group --- VG Name VolGroup00 System ID Format lvm2 Metadata Areas 1 Metadata Sequence No 3 VG Access read/write VG Status resizable MAX LV 0 Cur LV 2 Open LV 2 Max PV 0 Cur PV 1 Act PV 1 VG Size 189.66 GB PE Size 32.00 MB Total PE 6069 Alloc PE / Size 6069 / 189.66 GB Free PE / Size 0 / 0 VG UUID QeetG1-sSbh-g4Sp-bnbQ-9ZdD-Co1q-aoJe6t -------------------------------------------------------------------------------------------------- # fdisk -l Disk /dev/sda: 203.9 GB, 203928109056 bytes 255 heads, 63 sectors/track, 24792 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sda1 * 1 13 104391 83 Linux /dev/sda2 14 24773 198884700 8e Linux LVM Disk /dev/sdb: 203.9 GB, 203928109056 bytes 255 heads, 63 sectors/track, 24792 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sdb1 * 1 13 104391 83 Linux /dev/sdb2 14 24773 198884700 8e Linux LVM -------------------------------------------------------------------------------------------------- # lvm dumpconfig devices { dir="/dev" scan="/dev" preferred_names=[] filter="a/.*/" cache_dir="/etc/lvm/cache" cache_file_prefix="" write_cache_state=1 sysfs_scan=1 md_component_detection=1 ignore_suspended_devices=0 } activation { missing_stripe_filler="/dev/ioerror" reserved_stack=256 reserved_memory=8192 process_priority=-18 mirror_region_size=512 readahead="auto" mirror_log_fault_policy="allocate" mirror_device_fault_policy="remove" } global { umask=63 test=0 units="h" activation=1 proc="/proc" locking_type=1 fallback_to_clustered_locking=1 fallback_to_local_locking=1 locking_dir="/var/lock/lvm" } shell { history_size=100 } backup { backup=1 backup_dir="/etc/lvm/backup" archive=1 archive_dir="/etc/lvm/archive" retain_min=10 retain_days=30 } log { verbose=0 syslog=1 overwrite=0 level=0 indent=1 command_names=0 prefix=" " } -------------------------------------------------------------------------------------------------- # pvcreate -M 2 /dev/sda2 Found duplicate PV g7ZWtzNQcHx2PMQghP0NBHDXuYcaYqAt: using /dev/sdb2 not /dev/sda2 Found duplicate PV g7ZWtzNQcHx2PMQghP0NBHDXuYcaYqAt: using /dev/sda2 not /dev/sdb2 Found duplicate PV g7ZWtzNQcHx2PMQghP0NBHDXuYcaYqAt: using /dev/sdb2 not /dev/sda2 Found duplicate PV g7ZWtzNQcHx2PMQghP0NBHDXuYcaYqAt: using /dev/sda2 not /dev/sdb2 Can't initialize physical volume "/dev/sda2" of volume group "VolGroup00" without -ff -------------------------------------------------------------------------------------------------- # pvcreate -M 2 -ff /dev/sda2 Found duplicate PV g7ZWtzNQcHx2PMQghP0NBHDXuYcaYqAt: using /dev/sdb2 not /dev/sda2 Really INITIALIZE physical volume "/dev/sda2" of volume group "VolGroup00" [y/n]? n /dev/sda2: physical volume not initialized -------------------------------------------------------------------------------------------------- # cat /proc/mdstat Personalities : unused devices: <none> _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/