[Informatics Forum] - IPMI power management for older Dell servers equipped with IPMI v1.5

Contents

These notes describe how to configure a Dell server in the Informatics Forum whose BMC implements IPMI v1.5 (rather than the current version v2.0) in order that its power can be remotely managed. They are additional to the notes which describe how to configure a Dell server to provide a console managed by IPMI Serial-over-Lan in the Informatics Forum.

Important: These instructions apply to the Informatics Forum only; there are separate instructions for configuring a Dell server equipped with an IPMIv1.5 for power management at either AT or KB.

1. Initial Baseboard Management Controller configuration

The BMC first needs to be configured at the BIOS level. Turn on or restart the machine, press Ctrl-E when prompted in order to enter the Remote Access Configuration Utility, then make the following changes:

Remote Access Configuration Utility DEFAULT: CHANGE TO:
IPMI Over LAN Off On
LAN Parameters ->
IP Address Source Static DHCP
MAC Address < take a note of this >
VLAN Enable Off On
VLAN ID 0001 468
LAN User Configuration ->
Account User Name: root root
Enter Password: < something you can remember >

Notes:

  1. The exact configuration changes necessary depend, unfortunately, on the exact model of machine involved; they may differ in detail from those above. The example above should at least make it clear what, exactly, the configuration is aiming to achieve.
  2. The above has been tested with the PowerEdge 1850 machine scimitar (i.e. the old mars7).

2. IP address / DNS / DHCP configuration

In order that the BMC can acquire an IP address via DHCP, the usual DNS and DHCP arrangements have to be made:

  1. Allocate an IP address for the BMC on the Forum server management subnet, 192.168.68/23.
  2. Ensure that the port to which NIC1 of the host machine is connected carries the corresponding VLAN SOL (i.e. the VLAN whose 802.1Q tag is 468) as an additional tagged VLAN. To achieve this, the machine's port entry in the relevant ports file needs to look something like:
    port  n myserver - S33 SOL
  3. Add the allocated IP address to the DNS, with the hostname set to <machinename>.bmc.inf.ed.ac.uk
  4. Edit the existing LCFG source profile of the machine to which the BMC belongs so that the DHCP resources for the BMC are set appropriately. The resources bmchostname and bmcmac must both be specified: bmchostname should be the fully-qualified domain name chosen in the preceding step; bmcmac should be the MAC address identified in Section 2 above.

Example:

  [sandilands]idurkacz: rfe -g lcfg/myserver
  ...[snip]...
  dhclient.hostname               myserver.inf.ed.ac.uk
  dhclient.mac                    00:1d:09:6a:c9:b7
  !dhclient.cluster               mSET(dhcp/all)

  /* BMC */
  dhclient.bmchostname            myserver.bmc.inf.ed.ac.uk
  dhclient.bmcmac                 00:1d:09:6a:c9:bb
  !dhclient.cluster               mADD(dhcp/forum/consoles)

  /* Inventory information */
  ...[snip]...

Allow time for these DNS and DHCP changes to propagate.

3. Final Baseboard Management Controller configuration

Reboot the machine; the BMC should now active on the network. (Note: you will probably not be able to test this by ping'ing the BMC from marriner. This appears to be normal for Dell BMC's which implement IPMI v1.5: they don't respond to ping requests.)

Now, set its 'root' user password to our standard one, using the conserver-ipmisetpass command (which is provided by the conserver component) as follows:

  1. ssh to marriner
  2. nsu to root
  3. Issue the command /usr/sbin/conserver-ipmisetpass -I lan <machinename>.bmc

In step 3, you will be prompted to enter the temporary password you set in Section 2 above.

4. Remote power control

If a machine has been set up as above, then its power supply can be remotely controlled from the Informatics Forum console server (currently, marriner) via IPMI. To do this, use the conserver-ipmipower command (a wrapper to ipmitool) which is provided by the conserver component:

  1. ssh to marriner
  2. nsu to root
  3. Issue the command /usr/sbin/conserver-ipmipower -I lan <bmchostname> <power command>

Note that the the -I lan switch is mandatory in the above command: only the lan channel is supported for remote communication in IPMI v1.5.

Examples:

  [marriner]root: /usr/sbin/conserver-ipmipower
  Usage: conserver-ipmipower [-hv] [-I <channel>] <bmchostname> <power command>
  Wrapper for 'ipmitool -I <channel> -H <bmchostname> chassis power <power command>'
  Options:        -h            This help
                  -v            Verbose
                  -I <channel>  Selects the IPMI interface to be used
                                Must be either 'lanplus' (the default) or 'lan'
  chassis power Commands: status, on, off, cycle, reset, diag, soft

  [marriner]root: /usr/sbin/conserver-ipmipower -I lan myserver.bmc status
  Chassis Power is on

The effect of the various power commands is as follows:

status Show current power status
on Power up chassis, and reboot
off Power down chassis
(Note that this does not initiate a clean shutdown: the effect is the same as abruptly hitting the front-panel power button.)
cycle Power cycle chassis
(Has the effect: abrupt power off, 1 second wait, power on.)
soft Initiate a soft shutdown and power-off of a live machine
(Has the effect of shutdown -h now.)

Note: The setting of the machine's BIOS AC Power Recovery parameter has no effect on any of the above behaviour. That setting affects the behaviour of the system when mains power is restored to the system as a whole (i.e. through the incoming power cables); but the fact that the IPMI interface is functional at all implies that mains power is being applied to the system. So, for example, a soft shutdown, followed by a on, should always result in a reboot.

For more information on the details of the available power commands, man ipmitool.

5. Possible problems and quirks; other observations

  1. The BIOS configuration page for configuring the BMC seems to differ depending on which model of Dell is in use, so it's difficult (referring to section 1 above) to be explicit about the exact configuration necessary.
  2. As mentioned in section 3 above, Dell IPMI v1.5 BMC's do not appear to respond to ping requests. That can be confusing, and certainly makes liveness testing difficult. Looking at the DHCP logs (found in /var/log/lcfg/syslog) on the relevant site DHCP server can be useful if you're trying to ascertain whether or not a BMC is acquiring an IP address as expected.
  3. In order for a BMC's IP configuration to be (re-)initialised, power may need to be completely cycled on the chassis of the machine; i.e. the power cable(s) may need to be completely pulled. (Again, whether or not this is in fact necessary probably depends on the model of the machine.) This has obvious implications for the configuration of a machine which is already up-and-running!
  4. Anecdotally, the BMC's on some older Dell servers may not work correctly when configured to use tagged VLANs. (Although I emphasise that the BMC on the PowerEdge 1850 used for testing did work correctly in this regard.) If you suspect problems of this kind in any particular case, allocate the BMC an address on the S33 or S32 subnets, and revise the above instructions accordingly. Again, note the preceding point: to be sure that the BMC has been reinitialised, it may be necessary to completely remove the power from the machine in question.
  5. According to an informational warning message emitted by a Dell PowerEdge 1850 (equipped with IPMI v1.5):
    "BMC management traffic will not function if the LAN on motherboard (LOM) is used in an EtherChannel or Link Aggregation team."
    The implication is that IPMI will probably not work as expected on a machine which is equipped with IPMI v1.5 and which has also been set up to use a pair of bonded ethernet interfaces. Certainly, IPMI traffic will not failover in such circumstances (as it does when configured appropriately on a Dell equipped with IPMI v2.0). Any such configuration should be tested - it's possible that the results will vary from one machine model to another.
  6. If you are not sure what version of IPMI an already-installed machine supports, it should be possible to find this out from an xterm as follows:
    • nsu to root.
    • Load the kernel modules necessary for the OpenIPMI kernel device driver:
        /sbin/modprobe ipmi_msghandler
        /sbin/modprobe ipmi_si
        /sbin/modprobe ipmi_devintf
      
    • Run the command ipmitool bmc info and look for the IPMI Version field.

-- IanDurkacz - 16 Nov 2009

Topic revision: r6 - 28 Sep 2010 - 15:54:31 - IanDurkacz
 
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