Server compatibility is, obviously, the most important part. However, your management workstation can give you some headaches too.

I’ve been working around an error message on my workstation, I/O error occurred, for quite some time. It happens when I try to download large files (and sometimes small files) from ESXi to my workstation using the Datastore Browser.

There is much consternation about this error on the intertubes, and not a lot of answers.

I found a file that would consistently reproduce this problem. Then I shut down my workstation, added an Intel Pro/1000 GT network card, moved the cable over from my onboard NVIDIA nForce Networking Controller, and Shazam! No more “I/O error occurred” for me.

Of course, YMMV.

While we’re on the subject, if you got here as a result of searching for information about server compatibility, here are some helpful links:

• VMware’s Official HCLs
• Unofficial Whitebox (and not white box) Compatibility List
• Another unofficial whitebox list.
• GRC “Securable” app, good for telling whether your system has some commonly needed building blocks.

 The first link is the official VMware hardware compatibility list set. It has a very large number of servers, including which processors, RAID controllers, and network controllers to include in them when there is a choice to be made during parts selection on the vendor website.

Sometimes brand new servers are not in this list, but if you look at the previous model or similar models, you can sometimes find that the server you are querying about has the same processor family, same RAID controller, same network cards, etc in it. In those cases, it’s a pretty good bet that it will be compatible. Of course, the only way to be absolutely sure is to put an ESXi installer disk in the drive and try it. It only takes 10 minutes.

The second and third links include some brand name servers that are not on the HCL but have been tested and posted about in forums. You have to be careful with that because the people who post don’t always specify which controllers and which processor they used when testing. For example, they might say “The Dell Poweredge 840 works fine with ESXi.” without saying whether they used the onboard SATA (no RAID) controller or the PERC5/i controller. If it works with the onboard controller but does not work with the RAID controller, that isn’t really going to be useful for us at a client site.

The second link also includes lists of individual motherboards, SATA controllers, and network cards that are known to work. From this list, you can put together an inexpensive white-box computer with your choice of brand names.

Tags: compatibility, ESXi, HCL, I/O error occurred, whitelist

Perhaps you are not terribly impressed with the Datastore Browser that is built into the Virtual Infrastructure Client. Maybe it’s not the most efficient way to transfer files around.

Here are some tips to help you along the way:

Web Access to the ESXi file system:
https://192.168.0.2/folder?dsName=datastore1
Substitute your ESXi server’s IP address and the name of your datastore. You can download files via web browser. I’m not sure it’s faster for downloading large files, but if nothing else, it will give you a better progress bar. It is certainly faster for browsing around in the file system. If you are plagued by the dreaded “I/O error occurred” problem, and don’t want to use WinSCP or don’t have access to the server console to enable SSH, it will do the job.

PuTTY access to the console, and WinSCP access to the ESXi file system:

1. Go to the ESXi console and press alt+F1
2. Type: unsupported 
3. Enter the root password
4. At the prompt type “vi /etc/inetd.conf”
5. Look for the line that starts with “#ssh” (you can search with pressing “/”)
6. Remove the “#” (press the “x” if the cursor is on the character)
7. Save “/etc/inetd.conf” by typing “:wq!”
8. Restart the host server.

Note: you can avoid restarting the server, but it’s no longer as easy as restarting services.sh. You need to:

1. Run ps | grep inetd
2. Look through the output for something like 1299 1299 busybox       inetd, process id 1299
3. Run kill -HUP <process_id>

ALT+F2 gets you back to the main management screen.

Tags: datastore browser, ESXi, I/O error occurred, putty, ssh, unsupported, winscp