4.9. Attaching and Configuring the Data Disk

ssh username@instance_external_ip

# ssh username@instance_external_ip

fdisk -l /dev/sdb

# fdisk -l /dev/sdb

Disk /dev/sdb: 10984.4 GB, 10984378859520 bytes
255 heads, 63 sectors/track, 1335441 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x00000000

Create metadata LV with the maximum supported size of 16GB
Create data LV with the remainder of the VG space
The lvconvert command below required 4096 free extents, so reduce the LV
Convert our LVs to a thin pool
Disable zeroing of thin pool chunks for performance boost
The -V flag for lvcreate does not allow a ‘100%FREE’ option like -l does.
So we’ll get the size of rhgs_pool from lvs for maximum efficiency
Create the thin LV for the bricks
Create the XFS filesystem with 512B inode size and 8KB directory block size
This step may take a while...
Create mountpoint and fstab entry

#!/bin/bash
pvcreate /dev/sdb
vgcreate rhgs_vg /dev/sdb
# Create metadata LV with the maximum supported size of 16GB
lvcreate -L 16777216K --name rhgs_pool_meta rhgs_vg
# Create data LV with the remainder of the VG space
lvcreate -l 100%FREE --name rhgs_pool rhgs_vg
# The lvconvert command below required 4096 free extents, so reduce the LV
lvreduce -f -l 4096 /dev/rhgs_vg/rhgs_pool
# Convert our LVs to a thin pool
lvconvert --yes --thinpool rhgs_vg/rhgs_pool --poolmetadata rhgs_vg/rhgs_pool_meta
# Disable zeroing of thin pool chunks for performance boost
lvchange --zero n rhgs_vg/rhgs_pool
# The -V flag for lvcreate does not allow a ‘100%FREE’ option like -l does.
# So we’ll get the size of rhgs_pool from lvs for maximum efficiency
LVSIZE=$(lvs --units g | grep rhgs_pool | awk '{print $4}' | awk -F. '{print $1}')
# Create the thin LV for the bricks
lvcreate -V ${LVSIZE}G -T rhgs_vg/rhgs_pool -n rhgs_lv
# Create the XFS filesystem with 512B inode size and 8KB directory block size
# This step may take a while...
mkfs.xfs -f -i size=512 -n size=8192 -L rhgs_lv /dev/rhgs_vg/rhgs_lv
# Create mountpoint and fstab entry
mkdir -p /rhgs/bricks
echo "LABEL=rhgs_lv /rhgs/bricks xfs rw,inode64,noatime,nouuid 1 2" >> /etc/fstab
mount /rhgs/bricks
df -h /rhgs/bricks