In the previous post about the ESXi network IOchain we explored the various constructs that belong to the network path.
This blog post builds on top of that and focuses on the tools for advanced network troubleshooting and verification. Today, vSphere ESXi is packaged with a extensive toolset that helps you to check connectivity or verify bandwidth availability. Some tools are not only applicable for inside your ESXi box, but also very usable for the physical network components involved in the network paths.
Access to the ESXi shell is a necessity as the commands are executed here. A good starting point for connectivity troubleshooting is the esxtop network view. Also, the esxcli network commandlet provides a lot of information. We also have vmk ping, traceroute at our disposal. However, if you are required to dig deeper into an network issue, the following list of tools might help you out:.
This command can get you a lot of deep dive insights on what is happening under the covers of networking on a ESXi host as it can collect port stats and. The net-stats -h command displays all flags.VMworld 2017 - SER2965BU - Advanced Troubleshooting of VMware ESXi Server 6.x for vSphere Gurus
The most common one being the list option. This information is also used for input for other tools described in the blog post. The latter was already shipped with ESX i since the early versions. Both tools compliment each other and can be used together or separately. The tcpdump-uw tool is only able to capture packets at the VMkernel interface level. The pktcap-uw tool allows you to also capture frames at the uplink, vSwith or, virtual port levels.
Therefor, is provides for a lot more flexibility and improved troubleshooting. We have a KB article that provides detailed information about different options using pktcap-uw. I would like to highlight some of the options with regards to the diagram we know from the previous blog post. It details on what syntax to use to get the correct data of the network path level of choice.
Server Fault is a question and answer site for system and network administrators. It only takes a minute to sign up. I followed this vmware guide to remove a storage device and replace with another.
Everything worked fine apart from the fact the the datastore still show on the list as inactive. During the procedure I'm supposed to:. I had another one to remove and managed to figure out how to do it correctly by adding another step after 2.
Does anybody know how to remove this inactive ghost datastore? I actually want to use the same name for the new datastore so can't really turn my blind eye on it. If the VMs were connected to the datastore when the snapshot was made the VM will be connected to it until you remove the snapshot.
I had an issue once with an inaccessible NFS datastore. Also look on the individual hosts and see if the data store is mounted. It may be a single file locked to a host causing this. I logged a case with VMware and they helped me by executing these commands in each of the affected ESXi host.
Sign up to join this community. The best answers are voted up and rise to the top. Home Questions Tags Users Unanswered. How to remove inactive datastore from vSphere 6. Ask Question. Asked 3 years, 3 months ago. Active 3 months ago. Viewed 32k times. During the procedure I'm supposed to: unmount the datastore detach storage device make sure it detached with esxcli storage core device detached list permanently remove device config with esxcli storage core device detached remove -d naa.
Any help would be greatly appreciated. Bart C.Dealing with very network heavy guests, however, does sometimes require some tweaking. The loss may not be significant enough to cause a real application problem, but may have some performance impact during peak times and during heavy load. Not unlike physical network cards and switches, virtual NICs must have buffers to temporarily store incoming network frames for processing.
During periods of very heavy load, the guest may not have the cycles to handle all the incoming frames and the buffer is used to temporarily queue up these frames.
If that buffer fills more quickly than it is emptied, the vNIC driver has no choice but to drop additional incoming frames. This is what is known as buffer or ring exhaustion. To demonstrate ring exhaustion in my lab, I had to get a bit creative. This removes all physical networking and allows the guests to communicate as quickly as possible without the constraints of physical networking components. Both are very minimal deployments with only the essentials. The driver installed is 1.
To generate large amounts of TCP traffic between the two machines, I used iperf 2. Although I could have done a bi-directional test, I decided to use one machine as the sender and the other as the receiver. This helps to ensure one side is especially RX heavy. On the sending VM iperf client machine I used the -P 12 option to execute twelve parallel streams.
I also let the test run for a five minute period using the -t option. Packet loss also equates to TCP re-transmissions, window size adjustment and possibly performance impact. Depending on your application and the severity of the loss, you may not notice any problems, but I can pretty much guarantee that a packet capture would contain TCP duplicate ACKs and re-transmissions. Was the sender receiving duplicate ACKs and as a result re-transmitted?
Indeed it was. Clearly, we dropped many frames due to buffering. Over 10, frames were dropped. Most Linux distros provide some good driver statistic information, but that may not always be the case.
Thankfully, you can also check statistics from ESXi. To find this, the net-stats -l command is very useful:. This is an unsupported tool and should be used with caution.
To begin, we can get some generic vSwitch port statistics to see if any drops occurred. As you can see above, the droppedRx count is over 10K — about what we observed in the Linux guest. This tells us that frames were dropped, but not why. And again, we see some more specific statistics that help us to understand why frames were dropped.
Both the first and second rings were exhausted thousands of times. On the receiving node, we can see that the maximum possible value isbut the current is In Windows, you can see the RX Ring and buffering settings in the network adapter properties window. Once again, you can see the current RX queue buffer size from ESXi and this value is generally more trustworthy. First, we can display the number of RX queues being used by the guest by running the following command:.
Above, we can see that this Linux VM has two queues — zero and one. Despite this, we can see that the first ring is actually twice the size as the Linux VM by default:. Warning : Modifying NIC driver settings may cause a brief traffic disruption. After setting it towe can see that the current hardware setting is actually two RX queues of K each. Note: This ethtool setting will be lost as soon as the VM reboots.Firstly, to put a host into maintenance mode there are two options.
To reboot a host from the command line we would use the vicfg-hostops —operation reboot command, to force a reboot you could add the —force option, similarly to shutdown a host you use —operation shutdown, which can also be used with the —force option.
The VMware CLI options have come a long way over the years and you can really quickly and easily automate a lot of tasks using esxcli, PowerCLI and the other command line tools. I would encourage all of you to check them out. All rights reserved. Not to be reproduced for commercial purposes without written permission. Matter of factly I have used them to upgrade a 5. As for the reboot, "dcui" will also allow you to reboot the box.
VMXNET3 RX Ring Buffer Exhaustion and Packet Loss
Or issue a plain "reboot" right there at the prompt. Not very consistent. Enter maintenance mode — esxcli system maintenanceMode set -e on Exit maintenance mode — esxcli system maintenanceMode set -e off Status — esxcli system maintenanceMode get. This site uses Akismet to reduce spam. Learn how your comment data is processed. April 15, Menu Skip to content. To reboot a host: To reboot a host from the command line we would use the vicfg-hostops —operation reboot command, to force a reboot you could add the —force option, similarly to shutdown a host you use —operation shutdown, which can also be used with the —force option.
The dark mode beta is finally here. Change your preferences any time. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. VMware ESXi systems provide a shell with specific commands like esxcli and works only on those nodes.
I want to write a script to read the system IP from a file, login each system and execute the command esxcli network ip get. Simplest fix is to use it with its full path f. You can find the valid path of the esxcli command on the esxi server with the command which esxcli.
Some info here about shell. Learn more. Asked 6 years, 1 month ago.
Quick Tip – Listing Image Profiles From an ESXi Patch Using ESXCLI
Active 1 year, 3 months ago. Viewed 16k times. The script is as below:! Active Oldest Votes. The issue is not with esxcli not installed or path set on esxi server.
When I do manual ssh, login to esxi and execute, that works fine. It is really simple to test: try to run anything from a scripted ssh with full path, and it will work. You can run scripts in ESXI with shell. There are some difference with shell and bash, Some info here about shell.
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We have two clusters with the same hardware specs, built with the same ESXi image, same ixgbe async driver, and the Intel 10 Gbps NIC has the same firmware version installed. But in one cluster, ethtool indicates the Rx maximum cannot be set aboveand the other indicates I found the reason is the MTU size. Just an FYI as it took me a while to figure out this behavior. I have this exact issue with an X on esx 6.
You can not post a blank message. Please type your message and try again. But I'm unsure then how the Rx ring buffer is useful for Jumbo Frames at bytes? I have the same question Show 1 Likes 1. This content has been marked as final. Show 3 replies. Go to original post. Retrieving data Correct Answers - 10 points.Predefined options for connection information such as target host, user name, and so on. Not required when you run the command in the ESXi Shell. Reports on or modifies state on the system.
You have the following choices:. No additional authentication is required. See the vSphere Management Assistant Guide. See Installing vCLI. Each time you run a command, you must specify authentication information.
If you run commands against ESXi 4. If you run commands against ESXi 5. You can drill down into the namespaces for additional help.
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You can therefore not run commands with --server pointing to a vCenter Server system even if you install vCLI 5. The ESXi Shell is disabled by default. You must enable the ESXi Shell before you can run commands in the shell. Run the command. For example, to list NAS storage devices, run the following command.
You can use --help at any level of esxcli for help on available namespaces, commands, or options. Help us improve this information. Send feedback to docfeedback vmware.
Log in to the shell.