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mcidrac

Boot a server from an ISO

The flagship workflow: serve an ISO over HTTP, mount it as virtual media, and boot the host from it. One tool does the whole chain.

1. Serve the ISO

Section titled “1. Serve the ISO”

The iDRAC streams the image from your URL for as long as it’s mounted — the server must stay up for the entire install and support HTTP range requests:

Terminal window
cd /path/to/isos && python3 -m http.server 80

Plain HTTP on the management LAN sidesteps the self-signed-certificate gotcha. If you must use HTTPS with a self-signed cert, first enable RFS.1.IgnoreCertWarning:

“Set the iDRAC attribute RFS.1.IgnoreCertWarning to Enabled on r740-lab.”

2. One-shot boot

Section titled “2. One-shot boot”

“Boot r740-lab from http://192.0.2.50/rocky-9.iso”

The four boot-to-ISO steps — eject, mount, boot-once, restart — each with an amber read-back verification loop, and the step ledger recorded underneath.

This runs idrac_boot_to_iso, which performs and verifies each step:

  1. Ejects any image already in the virtual CD (verified empty)
  2. Mounts your ISO (verified inserted)
  3. Sets Dell’s OEM boot-once attributes ServerBoot.1.BootOnce + FirstBootDevice=VCD-DVD (verified by re-reading)
  4. Restarts the host — only after step 3 verified

Why the OEM attributes instead of the standard Redfish Cd boot override? On a box with a physical DVD drive, Cd boots whichever optical device the BIOS enumerates first. VCD-DVD targets the virtual CD unambiguously.

If any step fails, the error carries a ledger of what completed, so you know exactly what state the BMC is in before retrying.

3. Watch the install

Section titled “3. Watch the install”

“Give me the console for r740-lab.”

idrac_console mints a one-shot HTML5 console URL (no login page) on firmware that supports it. Open it promptly — the embedded credentials expire in about a minute.

4. Clean up

Section titled “4. Clean up”

After the installer finishes:

“Unmount the virtual media on r740-lab.”

The boot-once flag clears itself after one boot, but the ISO stays mounted until ejected — and a mounted installer plus a stray boot-order change can restart the whole install. Stop your HTTP server too.

Staging without rebooting

Section titled “Staging without rebooting”

Pass reboot=false to stage everything (mount + boot-once) so the next boot, whenever it happens, enters the installer. Useful for maintenance windows.

a Supported Systems joint