[gpfsug-discuss] RAID type for system pool

[Buterbaugh, Kevin L]

Hi All,

So while I’m waiting for the purchase of new hardware to go thru, I’m trying to gather more data about the current workload.  One of the things I’m trying to do is get a handle on the ratio of reads versus writes for my metadata.

I’m using “mmdiag —iohist” … in this case “dm-12” is one of my metadataOnly disks and I’m running this on the primary NSD server for that NSD.  I’m seeing output like:

11:22:13.931117  W       inode    4:299844163        1    0.448  srv   dm-12                 <redacted>
11:22:13.932344  R    metadata    4:36659676         4    0.307  srv   dm-12                 <redacted>
11:22:13.932005  W     logData    4:49676176         1    0.726  srv   dm-12                 <redacted>

And I’m confused as to the difference between “inode” and “metadata” (I at least _think_ I understand “logData”)?!?  The man page for mmdiag doesn’t help and I’ve not found anything useful yet in my Googling.

This is on a filesystem that currently uses 512 byte inodes, if that matters.  Thanks…

Kevin

—
Kevin Buterbaugh - Senior System Administrator
Vanderbilt University - Advanced Computing Center for Research and Education
Kevin.Buterbaugh at vanderbilt.edu<mailto:Kevin.Buterbaugh at vanderbilt.edu> - (615)875-9633



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