If I used pxelinux and VirtualBox to create a an image of a machine, and stored it on an NFS share, would it work as a quick way to restore a server that died?The only part here that keeps confusing me is that usually when PXE booting is involved they talk about how the server that receives the image doesn't have a hard drive.   So typically, do you just make sure that your image is pointing at the correct infrastructure to do writes?  Or redundant infrastructure that you can write to?  Is this only done with certain types of servers?  Do you have to be sure that everything, os and applications fit in the memory of the machine?  Do the servers have to be on a separate vlan to make sure that when some other machine reboots it doesn't receive the image?
Is PXEBooting a way to quickly restore a server?
pxe
If I used pxelinux and VirtualBox to create a an image of a machine, and stored it on an NFS share, would it work as a quick way to restore a server that died?Yes, this is a possible approach to this problem. You could do this e.g. by using PXELINUX as your NBP; PXELINUX could load a compact Linux-based bootimage, and this bootimage could load a hard disk image from a server and write it to the local disk.I assume that CloneZilla could be used this way, although I've never tried that myself. Some distributions like Debian, Ubuntu and probably several others also can be installed by booting the installer via PXE, and you can supply custom configuration for a unattended installation.There are several problems with this approach though:PXE is insecure. Anyone with access to your LAN can set up a rogue DHCP server and distribute PXE NBPs to all computers in your LAN that are configured to boot via PXE. It's usually a bad idea to configure servers to boot via PXE; if your LAN isn't a well isolated management network, you need at the very least to make sure that your switches filter DHCP replies from all normal ports. Also if a PXE bootimage can load your OS image from a server, then so can anyone else... including vital secrets like the root password hash.You will lose all data and custom configuration from the affected server if you decide to restore this way. If the server doesn't have any important data (e.g. a caching server), then this won't be a big problem, but usually it is. Manually investigating and resolving an issue that prevents the server from working seems preferable to me.Imaging is IMO relatively inflexible. If you want to use this for several different servers, than you'll have to maintain several different images, which will possibly take up a lot of space. If you use only a single baseline image, you'll have to manually configure things like the IP address after the recovery. If you've made configuration changes to a server without updating the image, then you'll lose these changes during restore.Personally, I'd prefer using RAID and backup. The RAID will protect you from downtime when a hard disk fails, and if you lose data, you can restore the system completely (including configuration and data) from the backup. If it fails due to another reason, then investigate and resolve the issue.