Formatting and Mounting Bricks
Formatting and Mounting Bricks
Creating a Thinly Provisioned Logical Volume
To create a thinly provisioned logical volume, proceed with the following steps:
-
Create a physical volume(PV) by using the pvcreate command. For example:
# pvcreate --dataalignment 128K /dev/sdb
Here, /dev/sdb is a storage device. Use the correct dataalignment option based on your device.
Note
The device name and the alignment value will vary based on the device you are using.
-
Create a Volume Group (VG) from the PV using the vgcreate command: For example:
# vgcreate --physicalextentsize 128K gfs_vg /dev/sdb
It is recommended that only one VG must be created from one storage device.
-
Create a thin-pool using the following commands:
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Create an LV to serve as the metadata device using the following command:
# lvcreate -L metadev_sz --name metadata_device_name VOLGROUP
For example:
# lvcreate -L 16776960K --name gfs_pool_meta gfs_vg
-
Create an LV to serve as the data device using the following command:
# lvcreate -L datadev_sz --name thin_pool VOLGROUP`
For example:
# lvcreate -L 536870400K --name gfs_pool gfs_vg
-
Create a thin pool from the data LV and the metadata LV using the following command:
# lvconvert --chunksize STRIPE_WIDTH --thinpool VOLGROUP/thin_pool --poolmetadata VOLGROUP/metadata_device_name
For example:
# lvconvert --chunksize 1280K --thinpool gfs_vg/gfs_pool --poolmetadata gfs_vg/gfs_pool_meta
Note
By default, the newly provisioned chunks in a thin pool are zeroed to prevent data leaking between different block devices.
# lvchange --zero n VOLGROUP/thin_pool
For example:
# lvchange --zero n gfs_vg/gfs_pool
-
-
Create a thinly provisioned volume from the previously created pool using the lvcreate command:
For example:
# lvcreate -V 1G -T gfs_vg/gfs_pool -n gfs_lv
It is recommended that only one LV should be created in a thin pool.
Format bricks using the supported XFS configuration, mount the bricks, and verify the bricks are mounted correctly.
Run
mkfs.xfs -f -i size=512 -n size=8192 -d su=128k,sw=10 DEVICE
to format the bricks to the supported XFS file system format. Here, DEVICE is the thin LV(here /dev/gfs_vg/gfs_lv). The inode size is set to 512 bytes to accommodate for the extended attributes used by GlusterFS.Run
mkdir /mountpoint
to create a directory to link the brick to.Add an entry in /etc/fstab:
/dev/gfs_vg/gfs_lv /mountpoint xfs rw,inode64,noatime,nouuid 1 2
Run
mount /mountpoint
to mount the brick.Run the
df -h
command to verify the brick is successfully mounted:# df -h /dev/gfs_vg/gfs_lv 16G 1.2G 15G 7% /exp1