Loading

×Sorry to interrupt
CSS Error

Refresh

Cookie Preference Center

General Information on cookies

When you visit our website, we use cookies to ensure that we give you the best experience. This information does not usually directly identify you, but it can give you a more personalized web experience. Because we respect your right to privacy, you can choose not to allow some types of cookies by clicking on the different category headings to find out more and change your settings. However, blocking some types of cookies may impact your experience on the site and the services we are able to offer. Further information can be found in our

Cookie Policy.

Strictly Necessary

Strictly Necessary

Always Active

Strictly Necessary

Strictly necessary cookies are always enabled since they are essential for our website to function. They enable core functionality such as security, network management, and website accessibility. You can set your browser to block or alert you about these cookies, but this may affect how the website functions. For more information please visit www.aboutcookies.org or www.allaboutcookies.org.

Cookie Details‎

Performance

Performance

Performance

Performance cookies are used to analyze the user experience to improve our website by collecting and reporting information on how you use it. They allow us to know which pages are the most and least popular, see how visitors move around the site, optimize our website and make it easier to navigate.

Cookie Details‎

Please confirm your settings by refreshing the page.

Functional

Functional

Functional

Functional cookies help us keep track of your past browsing choices so we can improve usability and customize your experience. These cookies enable the website to remember your preferred settings, language preferences, location and other customizable elements such as font or text size. If you do not allow these cookies, then some or all of these services may not function properly.

Cookie Details‎

Advertising

Advertising

Advertising

Advertising cookies are used to send you relevant advertising and promotional information. They may be set through our site by third parties to build a profile of your interests and show you relevant advertisements on other sites. These cookies do not directly store personal information, but their function is based on uniquely identifying your browser and internet device.

Cookie Details‎

Advertising Cookies

Consent Leg.Interest

Select All Vendors

Select All Vendors

Select All Hosts

Select All

Clear Filters

Information storage and access

Apply

Confirm My Choices Reject All Allow All

My Subscriptions

Loading

Knowledge Base

An ESX host fails to boot after increasing the Service Console or system memory (1016239)

Last Updated: 2/26/2010Categories: Total Views: 11108Language:
English

Subscribe to get an email
newsletter with new updates

Please provide article feedback:

Symptoms

After increasing the amount of physical RAM or Service Console memory, you may experience these symptoms:

An ESX fails to boot

You may see a purple diagnostics screen that contains an error similar to:

NOT_IMPLEMENTED /build/mts/release/bora-84374/bora/vmkernel/main/util.c:83

Resolution

Cause

This issue occurs when the ESX VMkernel cannot allocate sufficient physical memory below 4GB during boot.

The ESX host requires memory below 4GB (called Low Memory) for the Service Console, drivers, and other uses. The Service Console is configured to use between 272-800MB of the lowest physical memory. The ESX VMkernel requires some low memory to keep trace of high memory pages. The exact amount of memory Reserved can be seen with cat /proc/vmware/mem.

Example Reservations are as follows:

With 256GB of physical memory installed in a server, the ESX VMkernel reserves 1289MB of Low Memory.

With 128GB of physical memory installed in a server, the ESX VMkernel reserves 644MB of Low Memory.

The relationship between Physical Low and High Memory is as follows:

Maximum Console OS memory = Total Low Memory - VMkernel Reserved Low Memory - ~100MB Drivers

The total amount of low memory available is typically 4GB. However, the System BIOS can reserve some of this memory, so less than 4GB is available to the operating system. At a high level, the memory map looks like the figures below:

The following lines within the /var/log/messages log file represent the memory map as presented by the BIOS:

Note: Memory ranges from 000000007ff76300 (2047MB) to 0000000100000000 (4096MB) are reserved by the BIOS and are not usable by the OS.

The following lines from /var/log/messages record the VMkernel interpretations of the RAM map:

Note: The line containing linux MA reflect the Machine Address memory ranges allocated (in bytes) to the service console. The Service Console is using the lower 272MB. The lines containing vmkernel MPN reflect the Machine Page Numbers (4k blocks) allocated for the VMkernel. The VMkernel is using memory ranges 272MB - 2047MB and 4GB - 256GB.

The table below contains several combinations of Physical Memory and Service Console Memory assignment, along with their impact on the amount Unreserved Low Memory available when 2GB of low memory is reserved by the BIOS. The combination of 256GB of Physical Memory and 800MB of Service Console Memory with only 2GB of Low Memory leaves the server with only 7MB of Unreserved Low Memory, insufficient for booting. In this case the ESX VMkernel startup stops with the purple diagnostics screen.

Impact of Memory Allocations

Physical Memory

Physical Low Memory

Reserved Low Memory

Service Console Memory

Unreserved Low Memory

256 GB

4096 MB

1289 MB

272 MB

2535 MB

256 GB

4096 MB

1289 MB

800 MB

2007 MB

256 GB

2048 MB

1289 MB

272 MB

487 MB

256 GB

2048 MB

1289 MB

800 MB

7 MB

128 GB

4096 MB

644 MB

272 MB

3180 MB

128 GB

4096 MB

644 MB

800 MB

2652 MB

128 GB

2048 MB

644 MB

272 MB

1132 MB

128 GB

2048 MB

644 MB

800 MB

604 MB

Resolution

For servers affected by this limitation, it is recommended that the Service Console memory be reduced to between 500MB - 650MB, or that the Physical System Memory be reduced by 16GB - 32GB. Make one of the following changes to increase the amount of Low Memory available below 4GB:

Reduce the amount of Physical Memory in the server.

Reduce the amount of Physical Memory reserved by the BIOS.

Note: The BIOS memory reservation may or may not be configurable in a particular server. Consult your hardware vendor for more information.

Reduce the amount of Service Console Memory assigned by using the following steps:

Restart the ESX host.

When presented the boot menu, ensure you have the default boot option highlighted.

Press the e key to edit the default boot option. A new list appears.

Use the arrow keys to highlight the line which starts with kernel /vmlinuz.

Press the e key to edit the line in the boot configuration. A prompt with the entire line will appear.

Use the arrow key to move over the portion of the line which has a parameter similar to the following:

mem=800M

Change the value to something between 500 and 650 megabytes. The format is mem=M.

Note: The exact threshold may vary depending on the hardware configuration. To determine the exact value, engage your hardware vendor or test different values.

Press enter to accept the changes.

Press the b key to boot the host using the configuration.

Note: The configuration change is not permanent. To make the change permanent, proceed to step 10.

Wait for the host to boot.

When the host has booted, open the vSphere Client and connect to the host.

Under the configuration tab, change the memory properties of the ESX host to ensure that the RAM assignment has been reduced. For more information on adjusting the RAM assignment using the vSphere Client, see Increasing the amount of RAM assigned to the ESX Server Service Console (1003501).

Detectable by VMware SkylineTM

Actions

Copy

link to clipboard
copied!

Print

Language:
English

Attachments

Additional Resources

KB
•
End Of General Availability of the Free vSphere Hypervisor (ESXi 7.x and 8.x) (2107518)

Result 1 of 1

Ask The Community

Get answers quickly from VMware experts in the community

Post Subject

CONTINUE IN COMMUNITIES

Related Products:

VMware ESX Server

Related Versions:

VMware ESX Server 3.5.x

VMware ESX 4.0.x

Take Our Survey

Support Assistant