Working with Multipath-Enabled iSCSI-Attached Volumes
When you attach a volume configured for the Ultra High Performance level, to optimize performance, the volume attachment must be enabled for multipath.
For more information, see Attaching Ultra High Performance Volumes. For how to confirm that the iSCSI attachment is multipath-enabled, see Checking if a Volume Attachment is Multipath-Enabled.
This topic describes how to work with iSCSI-attached volumes that are multipath-enabled.
Device Path
A device path is required for multipath-enabled volume attachments. When attaching a volume configured for the Ultra High Performance level, using the iSCSI attachment type, the Attach button is not enabled until you select a device path. For more information about device paths, see Connecting to Volumes With Consistent Device Paths.
If you change the performance of an attached volume to the Ultra High Performance level and it was attached without a device path, it will not be multipath-enabled. This means that it will not be capable of the Ultra High Performance level numbers, until you specify a device path. You need to detach the volume, and then specify a device path when you reattach it to the instance.
Determining the Friendly Name
To determine the friendly name for the multipath-enabled attached volume, connect to the instance and run the following command:
ls -l <Consistent_Device_Path>If you have the friendly name for the device, run the following command to retrieve the device path name
sudo multipath -ll <Friendly_Name>Create the Partition with fdisk
Use fdisk to partition the multipath-enabled volume, and use the n option to specify that
it's a new partition.
fdisk <Friendly_NameUse the p option to make it the primary partition.
Run the following command to list the partitions:
lsblkCreate the File System
Run the following command to create the file system:
mkfs.ext4 <Friendly_Name>Run the following commands to create a directory and mount the partition on the mount point:
mkdir /data mount <Friendly_Name> /datafstab Options
On Linux instances, if you want to automatically mount volumes on instance boot, you need
to set some specific options in the /etc/fstab file, or the instance
may fail to launch.
Retrieving the Volume UUID
Run the following command to use the blkid utility to get the UUIDs for the volume
blkidFor more information about this, see Volume UUIDs.
Use the _netdev Option
Add the following to the /etc/fstab file
<Volume_UUID> /data ext4 defaults,_netdev,noatime 0 2After you've updated the /etc/fstab file, run the following command
to mount the volume:
mount -a