The real-time models on the k1srm were downed by many problems.

1. LAN cable was broken.
k1srm was connected with DGS network as the 100Mbps.
In this case, RTFE cannot be booted up because PXE boot is timed out.
So I replaced the LAN cable with new one.

2. IO chassis was turned off.
Someone may be turned off the IO chassis without stopping the real-ties models and shutting down the RTFE.
I turned on the IO chassis and reboot up the RTFE.
Don't stopped IO chassis before stopping RTFE.

3. Kernel panic caused by bad DAC was occurred.
After rebooting, kernel panic was occurred.
Some DAC cards cause DAC BRC=0xffffff and kernel panic.
I booted up the RTFE without the DAC cards for checking that there are no problem on the IO chassis and RTFE.
After that I rebooted up the RTFE with the DAC cards and k1srm comes back online.