6.0.1

Table Of Contents
5 Select one of the following options:
n
To disable the per le scheduling mechanism, change the value to No.
N After you turn o the per le I/O scheduling model, your host reverts to a legacy
scheduling mechanism that uses a single I/O queue. The host maintains the single I/O queue for
each virtual machine and storage device pair. All I/Os between the virtual machine and its virtual
disks stored on the storage device are moved into this queue. As a result, I/Os from dierent
virtual disks might interfere with each other in sharing the bandwidth and aect each others
performance.
n
To reenable the per le scheduling mechanism, change the value to Yes.
6 Reboot the host for the changes to take eect.
Use esxcli Commands to Enable or Disable Per File I/O Scheduling
You can use the esxcli commands to change to I/O scheduling capability. The capability is enabled by
default.
In the procedure, --server=server_name species the target server. The specied target server prompts you
for a user name and password. Other connection options, such as a conguration le or session le, are
supported. For a list of connection options, see Geing Started with vSphere Command-Line Interfaces.
Prerequisites
Install vCLI or deploy the vSphere Management Assistant (vMA) virtual machine. See Geing Started with
vSphere Command-Line Interfaces. For troubleshooting, run esxcli commands in the ESXi Shell.
Procedure
u
To enable or disable per le I/O scheduling, run the following commands:
Option Description
esxcli system settings kernel set -s
isPerFileSchedModelActive -v
FALSE
Disable per le I/O scheduling
esxcli system settings kernel set -s
isPerFileSchedModelActive -v TRUE
Enable per le I/O scheduling
Chapter 17 Understanding Multipathing and Failover
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