QoS Current-Limiting Demonstration

Experiment Name: QoS Current-Limiting Demonstration of IBM Storage Scale Lifecycle Management

Experiment Content:
The purpose of this lab is to understand the basic operations and concepts of the QoS policy for IBM Storage Scale parallel file systems.

Experiment Resources:
IBM Storage Scale 5.1.1 software
Red Hat Enterprise Linux 8.3 (VM)

QoS Current-Limiting Demonstration of IBM Storage Scale Lifecycle Management

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1. Open IBM Storage Scale command line interface
   
   Click terminal - root@gpfs10... at the top of the experiment desktop
   Open IBM Spectrum Scale command line interface
   

    

2. Create a Fileset for QoS
   

   We are going to limit the current I/O in /ibm/gpfs/qos directory

   2.1 Create a fileset named qos and connect it to the /ibm/gpfs/qos directory
   mmcrfileset gpfs qos
mmlinkfileset gpfs qos -J /ibm/gpfs/qos

   2.2 Viewing fileset information
   mmlsfileset gpfs

   2.3 Enter the fileset directory created above
   cd /ibm/gpfs/qos

3. Enable QoS for filesystem
   

   QoS is an attribute of the Spectrum Scale file system, which is disabled by default. Here we enable the QoS function for the file system named gpfs

   3.1 Enable QoS function of the file system
   mmqos filesystem enable gpfs

   3.2 View the QoS status of the current file system
   mmqos fs status gpfs

4. Create User Class
   

   4.1 Create a user class for the fileset named qos
   mmqos class create gpfs --class "Class1" --fileset qos

   4.2 View Class information of the current file system
   mmqos class list gpfs

5. Create the throttle for speed limit condition
   

   5.1 Set the throttle for Class1, and there is unlimited
   mmqos throttle create gpfs --pool system --class Class1 -C all_ local --maxiops unlimited --maxmbs unlimited

   5.2 View speed limit information
   mmqos throttle list gpfs

   5.3 Via dd command to write 1000MB data and observe the speed limit (Note: it can be measured several times to check the average value)
   dd if=/dev/zero of=/ibm/gpfs/qos/test bs=1M count=1000

6. Limit throughput
   

   6.1 Set the maximum throughput of Class1 to 100Mbps
   mmqos throttle update gpfs --pool system --class Class1 -C all_local --maxmbs 100

   6.2 Viewing speed limit information
   mmqos throttle list gpfs

   6.3 Via dd command write 1000MB data and observe the speed limit (Note: Please try more for the command)
   dd if=/dev/zero of=/ibm/gpfs/qos/test bs=1M count=1000