Monday, March 11, 2013

Different Sized Disks in a RAID Group


We encountered an interesting situation up here recently, and it generated a lot of debate between the PSC’s.  We finally locked down the answer, and I figured I would write it up and spread the knowledge! 

 The issue was that a RAID DP group on a system had 13 450GB data drives, 1 450GB Parity drive, 1 600GB data drive, and 1 600GB DP drive.  The data drives were all right-sized to the same “effective used” size, but the 600GB DP drive was showing as not right-sized.  This was in debate because it was commonly believed that all disks within a single RAID Group were required to be the same effective size.

  In an amazing FAQ document (please find it attached), we found the following:


  The document is written by Jay White, a Technical Marketing Engineer widely regarded as the authority on NetApp storage subsystems.  It’s a fascinating series of scenario studies that comes highly recommended.

FAS2240 Cabling


Interesting: a single-chassis HA 2240’s installed without shelves still require SAS cabling.   In order to be considered MPHA, cable 0a-0b and 0b-0a across the two controllers.  A lot of NetApp people still don’t know this, so be sure your sales guy puts SAS cables on the SO.

Credit:NetApp

Sunday, March 10, 2013

Ha-config


Yesterday we booted up a new 7-mode cluster and saw a couple things:
  • The systems were rebooting rather than going to the setup prompt.
  • The systems’ NVRAM cards’ LED’s weren’t lit up correctly.
  • And an error message:

Cannot determine whether configuration should be stand-alone or HA. Chassis is in default configuration, controller is in default configuration, and the non-volatile memory is dirty. Boot into Maintenance mode and run the 'ha-config modify' command to set the controller and chassis configuration to stand-alone or HA, as appropriate. Setting the wrong configuration might lead to data loss. If you need assistance, contact support.

Mar 07 04:01:46 [localhost:haosc.config.unknown.nv:ALERT]: Cannot determine whether configuration should be stand-alone or HA. Chassis is in default configuration, controller is in default configuration, and the nonvolatile memory is dirty.

This is what we did to fix it.
  • Boot to special boot menu.
  • Choose 5 to get to maintenance mode.
  • Set these:
    • ha-config modify chassis ha
    • ha-config modify controller ha
  • Reboot to setup prompt
  • Configure initial setup
  • Cf enable
  • Verify via sysconfig that the systems knew their partner’s hostname and sysid now
  • Cf disable
  • Halt to loader prompt
    • Printenv
    • Verify psm-cc-config is true
    • Verify partner-sysid was properly set
  • Boot up and cf enable