VMware ESXi boot and the Config

Sadly this post will be really short as again, lots going on. Recovering a host that failed after a regular reboot, which had a superblock corruption on it’s main OS drive. Also, the BELK series will be done, I just need a bit more time. Sorry for the delays.

“Failed to load /sb.v00” [Inconsistent Data]

Since this drive was not on the main datastore on the host all the VMs were unaffected.

Now loading linux showed the drive data was till accessible, but I also had a feeling this USB drive was on it’s way out. I created a copy using DD, *sadly I didn’t do it the smart way and place it on a drive big enough to save it as a image file, but instead directly to another drive of the same size.

I tried to install the same image of ESXi on top of the current one in hopes it would fix the boot partition files along the way. This only made the host get past /sb.v00 and vault randomly past it with “Fatal Error: 6 [Buffer Too Small]”

I was pretty tired at this point since the server boot times are rather long and attempts were becoming tedious. I did another DD operation of the drive, to the same drive (still not having learned my lesson) and when I awoke to my dismay, it failed only transferring 5 gigs with an I/O error. This really made me sure the drive was on the way out, but it was still mountable (the boot partitions 5, 6 and 8)

At this point you might be wondering, why doesn’t he just re-install and reload a backup config? Which is fair question, however one was not on hand, but surely it must be somewhere on the drive. I know how to create and recover on a working host but a one that can’t boot? Then I found this gem.

Now through out my attempts I did discover the boot partitions to be 5 and 6 and I did even copy them from a new install to my copied version I made about and it did boot but was a stock config. I was stumped till I read the section from the above blog post on “How to recover config from a system that doesn’t boot”. Line 7 was what nailed it on the head for me:

“mount /dev/sda5 /mnt/sda5

7. In the /mnt/sda5 directory, you can find the state.tgz file that contains ESXi configuration. This directory (in which state.tgz is stored) is called /bootblank/ when an ESXi host is booted.”

I was just like … wat? That’s it. Grabbed the bad main drive mounted on a linux system, saw the state.tgz file and made a copy of it, connected the new drive that had a base ESXi config, replaced the state.tgz file with the one I copied, booted it and there was the host in full working state with all network configs and registered VMs and everything.

Not sure why the config is stored in the boot partition, but there you go. Huge Shout out to Michael Bose for his write I suggest you check it out. I have saved it case it disappears from the internet and I can re-publish it. For now just visit the link. 🙂

Upgrading a Windows Volume from MBR to GPT to support EUFI boot and features

I’m going to keep this post short, so there won’t be any use of the TOC plug I recently deployed. 😛

I recently used a img of a sysprepped machine I used to deploy new machines. To my dismay the image was created with an MBR partition and was mostly used via BIOS boot options. This isn’t very secure as many of the security features of EUFI.

It’s been well known that moving from MBR to GPT back in the day was a painful process. I won’t go over the details as this “Microsoft Mechanics” video does a decent job of doing this.

If you’d like a little more nitty gritty details, you can view this Technet Blog.

In short:

  1. Boot into PE.
  2. use “mbr2gpt” command to validate and convert the partition.
  3. Boot into the Mainboard Config (Bios/EUFI)
  4. Configure boot option to EUFI

Now THAT was easy!