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cat pants
Asked: 2012-05-04 10:01:04 +0800 CST

How to interpret this output from MegaCli? [duplicate]

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/opt/MegaCli -CfgDsply -a0 | less RAID Level : Primary-1, Secondary-3, RAID Level Qualifier-0

Almost positive this is not running a RAID3, my guess is a RAID 10, where "Primary" means what is being done in the "spans" (span being Mega Cli term for the first RAID operation blocks) and then the "RAID Level Qualifier" is the RAID level operation being done on top of the spans, and finally, "Secondary-3" means that there are 3 spans being RAID0'd across. This interpretation matches the disk space sanity checks, indeed the total capacity of the array is that of three physical drives. However, this interpretation and output syntax is convoluted to the point where a clarification is definitely needed.

megacli

4 Answers

  1. Take a look: http://globalroot.wordpress.com/2013/06/18/megacli-raid-levels/

    # Explanation of Raid Levels: 
['Primary-0, Secondary-0, RAID Level Qualifier-0'] = RAID-0
['Primary-1, Secondary-0, RAID Level Qualifier-0'] = RAID-1
['Primary-5, Secondary-0, RAID Level Qualifier-3'] = RAID-5
['Primary-6, Secondary-0, RAID Level Qualifier-3'] = RAID-6
['Primary-1, Secondary-3, RAID Level Qualifier-0'] = RAID-10

    And match:

    $ sudo /opt/MegaRAID/MegaCli/MegaCli64 -LDInfo -Lall -aALL | grep RAID
RAID Level          : Primary-1, Secondary-0, RAID Level Qualifier-0
RAID Level          : Primary-1, Secondary-3, RAID Level Qualifier-0

$ sudo ./megasasctl
a0d0      136GiB RAID 1   1x2  optimal
a0d1      272GiB RAID 10  2x2  optimal
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  2. Best Answer

    Your answer appears to start at page 13 of this SNIA specification http://www.snia.org/sites/default/files/SNIA_DDF_Technical_Position_v2.0.pdf

    Primary-1 "Mirrored array"

    Secondary-3 "Spanned 0x03 A combination of stripping and concatenations involving Basic VDs of different sizes."

    RAID Level Qualifier-0 "Mirroring across two extents"

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  3. Since MegaCli is not terribly well documented we can at least compare outputs

    My disks are in raid 10 (I checked in the bios)

    from MegaCLI:

     RAID Level: Primary-1, Secondary-0, RAID Level Qualifier-0


                Versions
            ================
Product Name    : ServeRAID M5015 SAS/SATA Controller
Serial No       : SV13409496
FW Package Build: 12.12.0-0047


               Device Present
             ================
Virtual Drives    : 1 
  Degraded        : 0 
  Offline         : 0 
Physical Devices  : 6 
  Disks           : 4 
  Critical Disks  : 0 
  Failed Disks    : 0
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  4. You should combine with the Span Depth info to determine what raid is it. for example, RAID Level : Primary-1, Secondary-3, RAID Level Qualifier-0 with Span Depth: 1 means RAID 1, while RAID Level : Primary-1, Secondary-3, RAID Level Qualifier-0 with Span Depth: 2 means RAID 13.

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