We have always had very slow host boot or reboot times (around 30+ minutes to boot an ESXi host, and around 4-5 hours to upgrade ESXi) with our Dell R620 Severs running Dual 12 Core Processors and 384 GBytes of RAM on each ESXi host.
Our R620's are connected to a Dell 10 Gbit Switch running iSCSI to an Equal Logic SAN and boot ESXi from integrated Mirrored SD Cards. Could those be to blame for the slow boots and upgrades? I expect a bit of slowness when the server is scanning the memory, hardware, etc. but once the ESXi software launches, either via a clean boot or restart, or during an upgrade, it is so insanely slow. It seems to take forever on every step of an upgrade whether it be from partitioning the drive, or just loading drivers. We do use update manager to run these upgrades and this issue has occurred in 5.0, 5.5, and 6.0.
Any thoughts on what could be causing this slow boot and upgrade time and more importantly, can anything be done to fix it? I'm leaning towards the SD Cards as the bottleneck, but if that is the case, I don't know that much can be done, show of changing the way we boot the servers such as changing to hard drives or booting from the SAN.
Once the hosts are booted up, Vcenter and the VM's run great without any bottlenecks.
What do you think?
Jim
