After about a week the issue has not happened again.  All the chassis' CMCs are working properly now, after the upgrade to 2.82 in all iDRACs and after setting the power cap to 6000W instead of 4000W
We have seven M1000e chassis all with 16x M630, 2x Force10MXL switches and dual CMC's with 6.21 firmware.  The chassis were set up between Aug and Dec 2021.  Everything worked fine until we started moving production traffic to the chassis.  Once all the blades had an average of 20% CPU load, parts of the CMC functions stopped working.   For instance, the initial CMC screen stays at "Initializing" forever, and no components are displayed. [IMAGE]Initial screen, stays at "Initializing" forever   When trying to reset the CMCs, this happens after clicking on the Troubleshooting link: [IMAGE]Trying to reset the CMCs We can login to the CMC through ssh.  Some commands work, and some never respond, and some return partial information.   All the time, the blades work properly, and iDRAC on the blades work properly, and so do the switches.  It is only the CMC that malfunctions. We've tried switching over to the standby CMC, and manually removing one CMC from the chassis, but nothing changes.  The racreset command does not work - it timeouts and never responds.   In the CMC log, there is a low memory message in the CMCs which are failing:   SeqNumber       = 40844 Message ID      = MEM8500 Category        = Audit AgentID         = CMC Severity        = Critical Timestamp       = 2021-10-11 05:37:49 Message         = Low memory condition detected. -------------------------------------------------------------------------------- SeqNumber       = 40843 Message ID      = MEM8501 Category        = Audit AgentID         = CMC Severity        = Warning Timestamp       = 2021-10-11 02:50:53 Message Arg   1 = 253968 Message Arg   2 = 25390 Message         = Low memory warning, 253968KB, 25390KB. --------------------------------------------------------------------------------   The date on the message is around the date we started sending production traffic to the blades.  This is the output of 'getversion':                             server-1    2.75.100.75 (02)       PowerEdge M630         iDRAC8       Y server-2    2.75.100.75 (02)       PowerEdge M630         iDRAC8       Y server-3    2.75.100.75 (02)       PowerEdge M630         iDRAC8       Y server-4    2.75.100.75 (02)       PowerEdge M630         iDRAC8       Y server-5    2.75.100.75 (02)       PowerEdge M630         iDRAC8       Y server-6    2.75.100.75 (02)       PowerEdge M630         iDRAC8       Y server-7    2.75.100.75 (02)       PowerEdge M630         iDRAC8       Y server-8    2.75.100.75 (02)       PowerEdge M630         iDRAC8       Y server-9    2.75.100.75 (02)       PowerEdge M630         iDRAC8       Y server-10   2.75.100.75 (02)       PowerEdge M630         iDRAC8       Y server-11   2.75.100.75 (02)       PowerEdge M630         iDRAC8       Y server-12   2.75.100.75 (02)       PowerEdge M630         iDRAC8       Y server-13   2.75.100.75 (02)       PowerEdge M630         iDRAC8       Y server-14   2.75.100.75 (02)       PowerEdge M630         iDRAC8       Y server-15   2.75.100.75 (02)       PowerEdge M630         iDRAC8       Y server-16   2.75.100.75 (02)       PowerEdge M630         iDRAC8       Y                                     switch-1    MXL 10/40GbE                       A00              9.14(1.3)       switch-2    MXL 10/40GbE                       A00              9.14(1.3)         It does not include both CMCs, which are shown in the chassis where the CMCs do not display this issue.   Any ideas?     Thanks!  
CMC 6.21 stops working when blades are under load