6.0.1

Monitor Flash Devices
You can monitor certain critical ash device parameters, including Media Wearout Indicator, Temperature,
and Reallocated Sector Count, from an ESXi host.
Use the esxcli command to monitor ash devices.
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
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Run the following command to display the ash device statistics:
esxcli server=server_name storage core device smart get -d=flash device_ID
Best Practices for Flash Devices
Follow these best practices when you use ash devices in vSphere environment.
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Make sure to use the latest rmware with ash devices. Frequently check with your storage vendors for
any updates.
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Carefully monitor how intensively you use the ash device and calculate its estimated lifetime. The
lifetime expectancy depends on how actively you continue to use the ash device.
Estimate Lifetime of Flash Devices
When working with ash devices, monitor how actively you use them and calculate their estimated lifetime.
Typically, storage vendors provide reliable lifetime estimates for a ash device under ideal conditions. For
example, a vendor might guarantee a lifetime of 5 years under the condition of 20 GB writes per day.
However, the more realistic life expectancy of the device depends on how many writes per day your ESXi
host actually generates. Follow these steps to calculate the lifetime of the ash device.
Prerequisites
Note the number of days passed since the last reboot of your ESXi host. For example, ten days.
Procedure
1 Obtain the total number of blocks wrien to the ash device since the last reboot.
Run the esxcli storage core device stats get -d=device_ID command. For example:
~ # esxcli storage core device stats get -d t10.xxxxxxxxxxxxxxx
Device: t10.xxxxxxxxxxxxxxx
Successful Commands: xxxxxxx
Blocks Read: xxxxxxxx
Blocks Written: 629145600
Read Operations: xxxxxxxx
The Blocks Wrien item in the output shows the number of blocks wrien to the device since the last
reboot. In this example, the value is 629,145,600. After each reboot, it resets to 0.
vSphere Storage
136 VMware, Inc.