There is a CentOS 6 server that needed additional diskspace. I had no idea, that this server had an encrypted filesystem for one of it’s mount points. I thought the worst for procedures, but I found this one article that worked and worked well.
The situation was a VM on an ESXi server contained a LVM mount called for example, /backup that needed diskspace. Following the usual process of adding a disk via VMware, then scanning the OS for changes without restarting the VM, then fdisk, pvcreate, vgextend, and lvextend, all went well as planned.
for HOST in $(ls /sys/class/scsi_host) ; do echo '- - -'>"/sys/class/scsi_host/$HOST/scan" ; done fdisk -l | grep Disk lsblk # Note the -cu switch is used for CentOS6, not needed for CentOS7 fdisk -cu /dev/sdb pvcreate /dev/sdb1 vgscan vgextend vg_backup /dev/sdb1 lvscan lvextend /dev/vg_backup/lv_backup -l +100%FREE
It wasn’t until I attempted to resize the filesystem that I could not. I found several articles to determine if the filesystem is encrypted or not, but this tool seemed to be the cleanest approach and showed that the backup was sure enough en’crypt‘ed.
[root@backupserver ~]# dmsetup status | grep crypt backup: 0 50311168 crypt
Following the instructions from the source cited below, I was able to continue with this process.
# Determine the mount [root@backupserver ~]# mount | grep /backup /dev/mapper/backup on /backup type ext4 (rw) # Determine the status of the mount [root@backupserver ~]# cryptsetup status /dev/mapper/backup /dev/mapper/backup is active and is in use. type: LUKS1 cipher: aes-cbc-essiv:sha256 keysize: 256 bits device: /dev/mapper/vg_backup-lv_backup offset: 4096 sectors size: 50311168 sectors mode: read/write # Check the space for /backup ie. 24G [root@backupserver ~]# df -ThP | grep backup /dev/mapper/backup ext4 24G 19G 3.5G 85% /backup # Is it available via volume group, yes +8G [root@backupserver ~]# vgs | grep backup vg_backup 3 1 0 wz--n- 31.99g 0 # Is it available via logical volume, yes 8G [root@backupserver ~]# lvs | grep backup lv_backup vg_backup -wi-ao---- 31.99g # Resize the LUKS encrypted mount [root@backupserver ~]# cryptsetup resize /dev/mapper/backup # Now resize the space as usual. [root@backupserver ~]# resize2fs /dev/mapper/backup resize2fs 1.41.12 (17-May-2010) Filesystem at /dev/mapper/backup is mounted on /backup; on-line resizing required old desc_blocks = 2, new_desc_blocks = 2 Performing an on-line resize of /dev/mapper/backup to 8385024 (4k) blocks. The filesystem on /dev/mapper/backup is now 8385024 blocks long. # check it again. Note more space [root@backupserver backup]# cryptsetup status /dev/mapper/backup /dev/mapper/backup is active and is in use. type: LUKS1 cipher: aes-cbc-essiv:sha256 keysize: 256 bits device: /dev/mapper/vg_backup-lv_backup offset: 4096 sectors size: 67080192 sectors mode: read/write # Space is there. [root@backupserver backup]# df -ThP | grep backup /dev/mapper/backup ext4 32G 19G 11G 64% /backup