My migration experience from VMware Server to ESXi

I want to share the experience of my team on migration from the ancient VMware Server 2.0 to ESXi 4.1. In the course of optimizing maintenance costs, we were faced with the task of escaping with a heavily slowing down VMware Server under Windows for a free ESXi. The task was complicated by the territorial distribution of servers (throughout Russia) and the tight deadlines during which it was necessary to do this.

Given:

1. A dozen servers in remote locations. Take for granted that they have a remote control interface (DRAC / ILO / IP KVM). Without this, migration is greatly complicated by the large number of missions.
2. There are 3 virtual machines running on the servers - a domain controller, which also works like DNS and a DHCP server (virtual disk 40 gigabytes), WSUS + distribution kit (150 gigabytes), and a server that scans the branch office's network for vulnerabilities (another 40 gigabytes).
3. We don’t have intermediate servers on which we could temporarily put another ESXi and convert live machines to it, but to store the merged information we have file servers connected to our servers on the same switch - at best gigabit, but most often 100 megabits.
4. We have admin rights for all servers through AD groups (in a large company this is not always the case, but in this case we got them). We do not have local admin passwords for these servers.

Required:
Get rid of a bunch of Windows + VMware Server. Profit: we release OS licenses, and we also speed up the work of virtual machines, because from time to time the host machine devoured all processor resources (the reason is the tomcat process of the same relic hypervisor) —the virtual machines became very uncomfortable.

First of all, it was necessary to understand how and for how long it is possible to do all this, and what steps can be taken to speed it up.

The question of "how" after smoking mans and reading the Google issue was resolved in favor of copying the entire virtual machine directory from the hypervisor server to the file server and then backfilling it onto the newly installed ESXi using VMware Converter. On the pilot server, it turned out that the conversion speed (or rather, the uploading of the vmdk file to the host machine with ESXi by the converter) leaves much to be desired - after all, SCP. But other options (for example, there were ideas to include samba on ESXi and upload images directly to the datastor) ended up sticking to unsupported VMware scripts such as editing vmdk and vmx files, which I did not want to resort to. The variant with VMware-vdiskmanager was not liked due to the fact that I didn’t want to re-create the virtual machine configuration from scratch, and for some reason it didn’t turn out to be easy to run on all disks.
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The answer to the question “how long it will take” on the pilot server showed that the total time takes about three days, including the time of copying virtual machines back and forth. This is a lot, you need to accelerate, and most importantly - do not interfere with the work of the business. The first thought is to do on the weekends, and copy operations to be performed at night A business will be unhappy only in the absence of DHCP / DNS, which means that this machine is our priority, and it needs to be given the most attention - even on weekends there are those who want to work.

So, what happened in the end, in steps:

Training
We check remote access via DRAC / ILO, free space on the file server, and install VMware Standalone Converter and VSphere Client on the file server. We also install Standalone Converter on the domain controller. Copy the ISO distributions to the file server (in case we have DRAC / ILO) or cut the blank. It is very desirable to make a backup of the System State of the domain controller. We write down network settings of all virtualok.

Friday evening

1. You need to log in to the admins login for all virtuals - this is very useful if something happens with the network settings (and it happens - the network card for ESXi sees the guest OS as a new device), you can log in with the cached password.
2. We extinguish all cars, except the domain controller. We are waiting for VMware to delete the temporary working files of the machines (5 minutes), then at night put the copying of folders from the second and third virtual machines to the file server

Saturday

1. We switch off and copy the domain controller similarly to Friday servers.
2. Install ESXi and updates, configure the network, datastores and so on.
3. Run Standalone Converter on the file server. We convert the domain controller. This is approximately 5 hours with a 100-megabit link. Restoring the network settings of the controller.
4. Now we have a guest Windows, and with it the converter will run faster. As practice has shown, several times. From the domain controller we convert our WSUS, and on the file server in parallel - the third server. Their conversion will end at about the same time.

Now we just need to check on Sunday whether everything has been converted, return the network settings and drag out the settings of ESXi itself.

So, we got a scheme with extremely small time for human participation and parallelization of tasks, which allowed one person to “spud” 3 or more branches over the weekend.

If someone finds flaws in what we have thought of or knows how else to speed up the process, I will only be glad, it is always good to learn.