Choosing a RAID level for a storage server
Eight 12 TB drives give you 96 TB raw and four sensible ways to arrange them. What each level costs in capacity, what it buys in redundancy, and how long a rebuild really takes.
Every dedicated machine ships with out-of-band access, so a reinstall is yours to run at 3 a.m. without a ticket. The order of operations, and the three places it usually goes wrong.
Every dedicated machine ships with IPMI / out-of-band access, reachable from your client area. It is an independent little computer on the motherboard: it works when the server is powered off, when the OS will not boot, and when your firewall rule locked you out. Power cycling, mounting an ISO and reinstalling the OS are all yours to do, at any hour, without opening a ticket.
Log in to the IPMI web interface and open the remote console (labelled iKVM, Virtual Console, iDRAC console or iLO Remote Console depending on the board). Modern boards serve an HTML5 console; older ones offer a Java client and will make you edit a security exception. Confirm you can see the current screen and that your keystrokes arrive before you go further — a console that only paints is a console you cannot install from.
Take a note of the current network configuration while the machine is still up:
ip -br addr
ip route
cat /etc/resolv.conf
You will need the address, gateway and prefix during the install, and after the wipe there is nowhere to look them up.
In the console's virtual media menu, attach your ISO image as a virtual CD/DVD. Two things bite here:
Set the one-time boot device — "Boot Override", "Boot Once", or the equivalent on your board — rather than editing the permanent boot order. Then power-cycle from the IPMI power menu.
This is the single most common way a reinstall goes wrong: a permanent boot-order change that nobody undoes leaves the machine booting the installer forever, and it looks exactly like a dead server from the outside.
If the board offers no one-time option, change the order, but write yourself a note to change it back.
Nothing special here — it is the same installer you would run locally, driven through a slightly laggy console. Three things to get right while you are in it:
/dev/sda.When the installer asks to reboot:
Treat the BMC as a device that must never be publicly reachable. BMC firmware is patched slowly and has a long history of authentication bugs. Reach it through the access your client area provides, restrict it to known addresses where you can, and never reuse a password with it.
Usually a display that has gone to sleep or a console session that is stale: send a key, or close and reopen the console. If it stays blank through a power cycle, capture what you see and open a ticket — that pattern can mean the machine is not POSTing, which is a hardware question.
VPS instances use the VNC console in the client area. You can upload your own ISO and install over it the same way, and standard Linux templates are available if you would rather not.
If a template-based reinstall is offered for your product in the client area, that is the faster path. IPMI is what you use for a custom ISO, a non-standard partition layout, or when the machine will not boot.
After the reinstall, confirm the network is delivering what it should — how to verify your port speed — and secure the machine before you put anything on it. More material lives in the knowledge base.