1. (Guessing) perhaps it was considered useful to distinguish inode traffic from log traffic and just lump other metadata together. 2. A 512 byte inode has space for up to 384 bytes of data-in-inode data. (Says tsdbfs )
From: "Buterbaugh, Kevin L" <kevin.buterba...@vanderbilt.edu> To: gpfsug main discussion list <gpfsug-discuss@spectrumscale.org> Date: 09/11/2018 11:49 AM Subject: Re: [gpfsug-discuss] RAID type for system pool Sent by: gpfsug-discuss-boun...@spectrumscale.org Hi Marc, Understood … I’m just trying to understand why some I/O’s are flagged as metadata, while others are flagged as inode?!? Since this filesystem uses 512 byte inodes, there is no data content from any files involved (for a metadata only disk), correct? Thanks… Kevin On Sep 11, 2018, at 9:12 AM, Marc A Kaplan <makap...@us.ibm.com> wrote: Metadata is anything besides the data contents of your files. Inodes, directories, indirect blocks, allocation maps, log data ... are the biggies. Apparently, --iohist may sometimes distinguish some metadata as "inode", "logData", ... that doesn't mean those aren't metadata also. From: "Buterbaugh, Kevin L" <kevin.buterba...@vanderbilt.edu> To: gpfsug main discussion list <gpfsug-discuss@spectrumscale.org> Date: 09/10/2018 03:12 PM Subject: [gpfsug-discuss] RAID type for system pool Sent by: gpfsug-discuss-boun...@spectrumscale.org From: gpfsug-discuss-ow...@spectrumscale.org Subject: Re: [gpfsug-discuss] RAID type for system pool Date: September 10, 2018 at 11:35:05 AM CDT To: k...@accre.vanderbilt.edu 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 _______________________________________________ gpfsug-discuss mailing list gpfsug-discuss at spectrumscale.org http://gpfsug.org/mailman/listinfo/gpfsug-discuss _______________________________________________ gpfsug-discuss mailing list gpfsug-discuss at spectrumscale.org https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fgpfsug.org%2Fmailman%2Flistinfo%2Fgpfsug-discuss&data=02%7C01%7CKevin.Buterbaugh%40vanderbilt.edu%7C2dbbb1fe9f5a4b80aa6b08d617f0a664%7Cba5a7f39e3be4ab3b45067fa80faecad%7C0%7C0%7C636722719686369131&sdata=uOPawxUhx4Wvxja5%2FLvJJMpAHj3uRb0Q1eiogmRXGgw%3D&reserved=0 _______________________________________________ gpfsug-discuss mailing list gpfsug-discuss at spectrumscale.org http://gpfsug.org/mailman/listinfo/gpfsug-discuss
_______________________________________________ gpfsug-discuss mailing list gpfsug-discuss at spectrumscale.org http://gpfsug.org/mailman/listinfo/gpfsug-discuss