EDIT** I have a volume group consisting of 5 RAID1 devices grouped together into a lvm and formatted with xfs. The 5th RAID device lost its RAID config (cat /proc/mdstat does not show anything). The two drives are still present (sdj and sdk), but they have no partitions. The LVM appeared to be happily using sdj up until recently. (doing a pvscan showed the first 4 RAID1 devices + /dev/sdj) I removed the LVM from the fstab, rebooted, then ran xfs_check on the LV. It ran for about half an hour, then stopped with an error.

I tried rebooting again, and this time when it came up, the logical volume was no longer there. It is now looking for /dev/md5, which is gone (though it had been using /dev/sdj earlier). /dev/sdj was having read errors, but after replacing the SATA cable, those went away, so the drive appears to be fine for now.

Can I modify the /etc/lvm/backup/dedvol, change the device to /dev/sdj and do a vgcfgrestore? I could try doing a pvcreate --uuid KZron2-pPTr-ZYeQ-PKXX-4Woq-6aNc-AG4rRJ /dev/sdj to make it recognize it, but I'm afraid that would erase the data on the drive

UPDATE: just changing the pv to point to /dev/sdj did not work

vgcfgrestore --file /etc/lvm/backup/dedvol dedvol
  Couldn't find device with uuid 'KZron2-pPTr-ZYeQ-PKXX-4Woq-6aNc-AG4rRJ'.
  Cannot restore Volume Group dedvol with 1 PVs marked as missing.
  Restore failed.

pvscan
  /dev/sdj: read failed after 0 of 4096 at 0: Input/output error
  Couldn't find device with uuid 'KZron2-pPTr-ZYeQ-PKXX-4Woq-6aNc-AG4rRJ'.
  Couldn't find device with uuid 'KZron2-pPTr-ZYeQ-PKXX-4Woq-6aNc-AG4rRJ'.
  Couldn't find device with uuid 'KZron2-pPTr-ZYeQ-PKXX-4Woq-6aNc-AG4rRJ'.
  Couldn't find device with uuid 'KZron2-pPTr-ZYeQ-PKXX-4Woq-6aNc-AG4rRJ'.
  PV /dev/sdd2        VG VolGroup00   lvm2 [74.41 GB / 0    free]
  PV /dev/md2         VG dedvol       lvm2 [931.51 GB / 0    free]
  PV /dev/md3         VG dedvol       lvm2 [931.51 GB / 0    free]
  PV /dev/md0         VG dedvol       lvm2 [931.51 GB / 0    free]
  PV /dev/md4         VG dedvol       lvm2 [931.51 GB / 0    free]
  PV unknown device   VG dedvol       lvm2 [1.82 TB / 63.05 GB free]
  Total: 6 [5.53 TB] / in use: 6 [5.53 TB] / in no VG: 0 [0   ]

vgscan
  Reading all physical volumes.  This may take a while...
  /dev/sdj: read failed after 0 of 4096 at 0: Input/output error
  /dev/sdj: read failed after 0 of 4096 at 2000398843904: Input/output error
  Found volume group "VolGroup00" using metadata type lvm2
  Found volume group "dedvol" using metadata type lvm2

vgdisplay dedvol
  --- Volume group ---
  VG Name               dedvol
  System ID             
  Format                lvm2
  Metadata Areas        5
  Metadata Sequence No  10
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                1
  Open LV               0
  Max PV                0
  Cur PV                5
  Act PV                5
  VG Size               5.46 TB
  PE Size               4.00 MB
  Total PE              1430796
  Alloc PE / Size       1414656 / 5.40 TB
  Free  PE / Size       16140 / 63.05 GB
  VG UUID               o1U6Ll-5WH8-Pv7Z-Rtc4-1qYp-oiWA-cPD246

dedvol {
        id = "o1U6Ll-5WH8-Pv7Z-Rtc4-1qYp-oiWA-cPD246"
        seqno = 10
        status = ["RESIZEABLE", "READ", "WRITE"]
        flags = []
        extent_size = 8192              # 4 Megabytes
        max_lv = 0
        max_pv = 0

        physical_volumes {

                pv0 {
                        id = "Msiee7-Zovu-VSJ3-Y2hR-uBVd-6PaT-Ho9v95"
                        device = "/dev/md2"     # Hint only

                        status = ["ALLOCATABLE"]
                        flags = []
                        dev_size = 1953519872   # 931.511 Gigabytes
                        pe_start = 384
                        pe_count = 238466       # 931.508 Gigabytes
                }

                pv1 {
                        id = "ZittCN-0x6L-cOsW-v1v4-atVN-fEWF-e3lqUe"
                        device = "/dev/md3"     # Hint only

                        status = ["ALLOCATABLE"]
                        flags = []
                        dev_size = 1953519872   # 931.511 Gigabytes
                        pe_start = 384
                        pe_count = 238466       # 931.508 Gigabytes
                }

                pv2 {
                        id = "NRNo0w-kgGr-dUxA-mWnl-bU5v-Wld0-XeKVLD"
                        device = "/dev/md0"     # Hint only

                        status = ["ALLOCATABLE"]
                        flags = []
                        dev_size = 1953519872   # 931.511 Gigabytes
                        pe_start = 384
                        pe_count = 238466       # 931.508 Gigabytes
                }

                pv3 {
                        id = "2EfLFr-JcRe-MusW-mfAs-WCct-u4iV-W0pmG3"
                        device = "/dev/md4"     # Hint only

                        status = ["ALLOCATABLE"]
                        flags = []
                        dev_size = 1953519872   # 931.511 Gigabytes
                        pe_start = 384
                        pe_count = 238466       # 931.508 Gigabytes
                }

                pv4 {
                        id = "KZron2-pPTr-ZYeQ-PKXX-4Woq-6aNc-AG4rRJ"
                        device = "/dev/md5"     # Hint only

                        status = ["ALLOCATABLE"]
                        flags = []
                        dev_size = 3907028992   # 1.81935 Terabytes
                        pe_start = 384
                        pe_count = 476932       # 1.81935 Terabytes
                }
        }