UEFI has been the official future of x86 PC firmware for a very long time, and for much of that time your machine's UEFI firmware has still been willing to boot your systems the traditional way x86 PCs booted before UEFI, with 'BIOS MBR' (generally using UEFI CSM booting). Some people have no doubt switched to booting their servers with UEFI (booting) years ago, but for various reasons we have long preferred BIOS (MBR) booting and almost always configured our servers that way if given a choice. Over the years we've wound up with a modest number of servers which only supported UEFI booting, but the majority of our servers and especially our generic 1U utility servers all supported BIOS MBR booting.

Well, those days are over now. We're refreshing our stock of generic 1U utility servers and the new generation are UEFI booting only. This is probably not surprising to anyone, as Intel has been making noises about getting rid of UEFI CSM booting for some time, and was apparently targeting 'by 2024' for server platforms. Well, it is 2024 and here we are with new Intel based server hardware without what Intel calls 'legacy boot support'.

(I'm aware we're late to this party, and it's quite possible that server vendors dropped legacy boot mode a year or two ago. We don't buy generic 1U servers very often; we tend to buy them in batches when we have the money and this doesn't happen regularly.)

To be honest, I don't expect UEFI booting to make much of a visible difference in our lives, and it may improve them in some ways (for example if our Linux kernels use UEFI to store crash information). I think we were right to completely avoid the early implementations of UEFI booting, but it ought to work fine by now if server vendors are accepting Intel shoving legacy boot support overboard. There will be new things we'll have to do on servers with mirrored system disks when we replace a failed disk, but Ubuntu's multi-disk UEFI boot story is in decent shape these days and our system disks don't fail that often.

(However, UEFI booting does introduce some new failures modes. We probably won't run into corrupted EFI System Partitions, since their contents don't get changed very often these days.)