C7000 Power-up sequence questions

[chuckk281]

Alex was looking to help his customer:

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My customer faces an issue with auto power-on of a full enclosure. One (AC) respectively four (DC) blades do not power on immediately due to the chosen N+N Power Redundancy configuration. The blades affected get to a degraded state due to power constraints.

What my customer wants to know from us now is a clear advisory on how to configure the OA in order to achieve a controlled and fast power-on of all blades after e.g. a power outage. They wanted to use the delay function, but there seems to be no clear guidance on the applicable delay to be used.

For them down-time is very critical and therefore the mechanisms to bring systems back up after an issue like a power outage are very important.

Thank you for your support.

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Reply from Dan:

What I’ve always heard is use 30 seconds as your minimum for I/O modules and 60 seconds for servers.

Then add padding based on server boot order.

So 60 seconds for phase 1 servers

90? Seconds for phase 2

120? for phase 3

etc.

Reply from Alex:

Hi Dan et al, Thank you very much for your response.

My customer has started their own trials on the right delay time and found that everything below 2.5 minutes did not work for them. What we are now looking for would be an HP “advisory” on this that we can officially present to the customer. Best would be an official document. Have you come across anything like that?

From  Fredy:

Alex,

The settings that Dan mentioned seem to be fairly close to the settings that were specified for the older P4800 VDI Solution.

Maybe you can use this as guidelines for your own environment and experimentation?? Just a thought….

Step 6—Set power-on sequence for disaster recovery

After the firmware has been upgraded, you may set the power-on sequence in the OA to ensure

proper recovery after catastrophic power failures.

1. Log in to the OA as Administrator.

2. Navigate to Enclosure Information→ Enclosure Settings→ Device Power Sequence.

3. Click the Interconnect Bays tab and configure the following settings.

Table 6 Power on delays for interconnect bays

Interconnect bays Power-on setting

1 and 2—Flex-10 modules After 3 minutes and 30 seconds

5 and 6—3Gb SAS BL Switches After 3 minutes

Setting the power-on delays for the Flex-10 modules and the 3Gb SAS BL Switches ensures

that the disks in the MDS600 disk enclosure have time to spin up.

4. Click the Device Bays tab.

5. Set the storage blade device bays to power on after 270 seconds.

NOTE: See Table 1 (page 5) for the preferred layout of the storage blades in the c7000

enclosure.

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Any other advice for Alex?