PX-Fast volumes using pxctl

This section provides instructions for performing operations on PX-Fast volumes using pxctl.

Create a PX-Fast volume

To create a PX-fast volume, run the following command on any of the worker nodes of your cluster:

pxctl volume create --fastpath <px-volume>

Volume successfully created: 913654286436616938

Attach a volume

Attach your PX-Fast volume to the host:

pxctl host attach <px-volume>

By default, a volume uses PX-Fast only when you attach it on the node that holds its replica. If you enable remote fastpath on the cluster, the volume can also use PX-Fast when you attach it on another node. For more information, see Enable remote fastpath on the cluster.

List volumes in your cluster

Run the following command to get the list of volumes within a cluster:

pxctl volume list

ID			NAME						SIZE	HA	SHARED	ENCRYPTED	PROXY-VOLUME	IO_PRIORITY	STATUS		SNAP-ENABLED	
1150247763189801500	pvc-xxxxxxxx-xxxx-xxxx-xxxx-84d9193d55a5	2 GiB	no	no		no		LOW		up - detached		no
79554029234843357	v1						1 GiB	no	no		no		LOW		up - detached		no
909303106655754070	v2						1 GiB	no	no		no		LOW		up - attached on 10.13.160.65	no

Note the ID or name of one of the volume; you can use it to view details using the pxctl command.

Get volume details

Run the following command to view the details of a volume:

pxctl volume inspect <px-volume>

Volume          	 :  909303106655754070
	Name            	 :  v2
	Size            	 :  1.0 GiB
	Format          	 :  ext4
	HA              	 :  1
	IO Priority     	 :  LOW
	Creation time   	 :  Oct 11 01:43:36 UTC 2022
	Shared          	 :  no
	Status          	 :  up
	State           	 :  Attached: xxxxxxxx-xxxx-xxxx-xxxx-502e658bc307 (10.13.160.65) (fastpath active)
	Last Attached   	 :  Oct 11 01:43:42 UTC 2022
	Device Path     	 :  /dev/pxd/pxd909303106655754070
	Mount Options          	 :  discard
	Reads           	 :  40
	Reads MS        	 :  20
	Bytes Read      	 :  1060864
	Writes          	 :  0
	Writes MS       	 :  0
	Bytes Written   	 :  0
	IOs in progress 	 :  0
	Bytes used      	 :  33 MiB
	Replica sets on nodes:
		Set 0
		  Node 		 : 10.13.160.65 (Pool xxxxxxxx-xxxx-xxxx-xxxx-f9131bf7ef9d )
	Replication Status	 :  Up

The State field shows fastpath active when the volume uses PX-Fast. If it does not, the volume uses the standard I/O path.

Get pool details servicing your volume

Run the following command to view the details of the pool servicing your volume:

pxctl service pool show

PX drive configuration:
Pool ID: 0 
	Type:  PX-StoreV2 
	UUID:  xxxxxxxx-xxxx-xxxx-xxxx-db8abe01d4f0 
	IO Priority:  HIGH 
	Labels:  medium=STORAGE_MEDIUM_SSD,beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,iopriority=HIGH,kubernetes.io/arch=amd64,kubernetes.io/hostname=username-vms-silver-sight-3,kubernetes.io/os=linux 
	Size: 25 GiB 
	Status: Online 
	Has metadata:  No 
	Balanced:  Yes 
	Drives:
	0: /dev/sda, Total size 32 GiB, Online
	Cache Drives:
	No Cache drives found in this pool
Metadata  Device:
	1: /dev/sdd, STORAGE_MEDIUM_SSD

Update a volume to enable PX-Fast

You can update an existing volume to use the PX-Fast functionality by running the following command:

pxctl volume update --fastpath <px-volume>

Volume          	 :  289859383805313381
Name            	 :  v5
Size            	 :  1.0 GiB
Format          	 :  ext4
HA              	 :  1
IO Priority     	 :  LOW
Creation time   	 :  Oct 14 02:35:02 UTC 2022
Shared          	 :  no
Status          	 :  up
State           	 :  detached
Mount Options          	 :  discard
Reads           	 :  0
Reads MS        	 :  0
Bytes Read      	 :  0
Writes          	 :  0
Writes MS       	 :  0
Bytes Written   	 :  0
IOs in progress 	 :  0
Bytes used      	 :  1.0 MiB
Replica sets on nodes:
		Set 0
		  Node 		 : 10.13.161.121 (Pool xxxxxxxx-xxxx-xxxx-xxxx-434152789beb )
Replication Status	 :  Detached

The volume is now eligible for PX-Fast. Portworx uses PX-Fast when you attach the volume and it has one replica. The volume must be attached on the node that holds its replica, unless you enable remote fastpath on the cluster.