Skip to main content

Using esxtop to identify VMware storage performance issues

Using esxtop to identify VMware storage performance issues

 

 

Configuring monitoring using esxtop
To monitor storage performance per HBA:
  1. Start esxtop by typing esxtop at the command line.
  2. Press d to switch to disk view (HBA mode).
  3. Press f to modify the fields that are displayed.
  4. To view the entire Device name, press SHIFT + L and enter 36 in Change the name field size.
  5. Press b, c, d, e, h, and j to toggle the fields and press Enter.
  6. Press s, then 2 to alter the update time to every 2 seconds and press Enter.
  7. See Analyzing esxtop columns for a description of relevant columns.
Note: The following options are only available in VMware ESX 3.5 and later.
To monitor storage performance on a per-LUN basis:
  1. Start esxtop by typing esxtop from the command line.
  2. Press u to switch to disk view (LUN mode).
  3. Press f to modify the fields that are displayed.
  4. Press b, c, f, and h to toggle the fields and press Enter.
  5. Press s, then 2 to alter the update time to every 2 seconds and press Enter.
  6. See Analyzing esxtop columns for a description of relevant columns.
To increase the width of the device field in esxtop to show the complete naa id:
  1. Start esxtop by typing esxtop at the command line.
  2. Press u to switch to the disk device display.
  3. Press L to change the name field size.
    Note: Ensure to use uppercase L.
  4. Enter the value 36 to display the complete naa identifier.

To monitor storage performance on a per-virtual machine basis:
  1. Start esxtop by typing esxtop at the command line.
  2. Type v to switch to disk view (virtual machine mode).
  3. Press f to modify the fields that are displayed.
  4. Press b, d, e, h, and j to toggle the fields and press Enter.
  5. Press s, then 2 to alter the update time to every 2 seconds and press Enter.
  6. See Analyzing esxtop columns for a description of relevant columns
Analyzing esxtop columns:
CMDS/s : This is the total amount of commands per second and includes IOPS (Input/Output Operations Per Second) and other SCSI commands such as SCSI reservations, locks, vendor string requests, unit attention commands etc. being sent to or coming from the device or virtual machine being monitored.In most cases CMDS/s = IOPS unless there are a lot of metadata operations (such as SCSI reservations)
DAVG/cmd :This is the average response time in milliseconds per command being sent to the device
KAVG/cmd :This is the amount of time the command spends in the VMkernel
GAVG/cmd :This is the response time as it is perceived by the guest operating system. This number is calculated with the formula: DAVG + KAVG = GAVG
If the response time increases to over 5000 ms (or 5 seconds), VMware ESX will time out the command and abort the operation. These events are logged; abort messages and other SCSI errors can be reviewed in the following logs:
  • ESX 3.5 and 4.x – /var/log/vmkernel
  • ESXi 3.5 and 4.x – /var/log/messages 
  • ESXi 5.x - /var/log/vmkernel.log

Comments

Post a Comment

Popular posts from this blog

  Issue with Aria Automation Custom form Multi Value Picker and Data Grid https://knowledge.broadcom.com/external/article?articleNumber=345960 Products VMware Aria Suite Issue/Introduction Symptoms: Getting  error " Expected Type String but was Object ", w hen trying to use Complex Types in MultiValue Picker on the Aria for Automation Custom Form. Environment VMware vRealize Automation 8.x Cause This issue has been identified where the problem appears when a single column Multi Value Picker or Data Grid is used. Resolution This is a known issue. There is a workaround.  Workaround: As a workaround, try adding one empty column in the Multivalue picker without filling the options. So we can add one more column without filling the value which will be hidden(there is a button in the designer page that will hide the column). This way the end user will receive the same view.  
Post a Comment
Read more

57 Tips Every Admin Should Know

Active Directory 1. To quickly list all the groups in your domain, with members, run this command: dsquery group -limit 0 | dsget group -members –expand 2. To find all users whose accounts are set to have a non-expiring password, run this command: dsquery * domainroot -filter “(&(objectcategory=person)(objectclass=user)(lockoutTime=*))” -limit 0 3. To list all the FSMO role holders in your forest, run this command: netdom query fsmo 4. To refresh group policy settings, run this command: gpupdate 5. To check Active Directory replication on a domain controller, run this command: repadmin /replsummary 6. To force replication from a domain controller without having to go through to Active Directory Sites and Services, run this command: repadmin /syncall 7. To see what server authenticated you (or if you logged on with cached credentials) you can run either of these commands: set l echo %logonserver% 8. To see what account you are logged on as, run this command: ...
Post a Comment
Read more
  The Guardrails of Automation VMware Cloud Foundation (VCF) 9.0 has redefined private cloud automation. With full-stack automation powered by Ansible and orchestrated through vRealize Orchestrator (vRO), and version-controlled deployments driven by GitOps and CI/CD pipelines, teams can build infrastructure faster than ever. But automation without guardrails is a recipe for risk Enter RBAC and policy enforcement. This third and final installment in our automation series focuses on how to secure and govern multi-tenant environments in VCF 9.0 with role-based access control (RBAC) and layered identity management. VCF’s IAM Foundation VCF 9.x integrates tightly with enterprise identity providers, enabling organizations to define and assign roles using existing Active Directory (AD) groups. With its persona-based access model, administrators can enforce strict boundaries across compute, storage, and networking resources: Personas : Global Admin, Tenant Admin, Contributor, Viewer Projec...
Post a Comment
Read more