[lug] Debugging I/O performance

[Dylan Richards]

Sorry to interrupt... but is there some way to unsubscribe from this
mailing list?

Thanks,
Dylan Richards

On Tue, Mar 13, 2018 at 10:13 AM, Rob Nagler <nagler at bivio.biz> wrote:

> We have some Dell m620s in a m1000e chassis. I was switching around disk
> controllers to figure out if the Dell H310 (non-RAID) worked better than
> the S110 (non-RAID or AHCI) was faster. One of the m620s has twice as slow
> disk I/O, and I can't figure out why.
>
> There are no errors in the logs. lshw, hdparm, etc. are identical. I
> walked through the BIOS config. Also, identical. Simple CPU benchmarks are
> identical. Fresh installs with the same CentOS 7 kickstart config (minimal
> install).
>
> Many details have been documented here: https://github.com/
> radiasoft/devops/wiki/DellRAID#performance
>
> The two identical machines are f2 and f3 with H310s. f4 is almost the same
> but uses an onboard controller (AHCI).
>
> I can afford to swap around m620s with some in our diskless cluster, which
> would avoid the problem. However, it seems to me there's something wrong,
> and I should understand what it is.
>
> Any ideas how to determine what's causing the performance difference?
>
> Thanks,
> Rob
>
>
> _______________________________________________
> Web Page:  http://secure-web.cisco.com/1Qvm9ik6x3WRR6tN5mn9mjoT01KkLyUC_
> NJ6GlDMDuBau5Y9Y3iKTJIXcJqlvMpkdeuno53cQhYaCcSFePB6sH5XmEaRd
> DBMMsjTntbEFDkCknKeZeoI_TExMDUwPy71gu3hDMwWnIW-Uco_rzj4gD0iC5u8_
> yd4horvuXyRdPsT9bpoHTSZXypFgakCHEDCofMdD09I-QDAgx8dYdI1Ce1-
> dKSFCDN5Sghwp6V9vcEzfgEPiRrXVOdHgKzNepqNB2OcRDZiGSV9iiLixt8GKwl_
> QzIh0GqNWjt0zYTvIt8Xd75xLDO2Yuj_YlblKiJdSizm0ySnqbGFUrt6jPrBG2AWOZE-kPWG_
> jICJY4VrsoApwxPVKoynXt3JV0onLuASWudqCdhY-7egYsrrFE9FIr_
> 3II541D8nF33oSCZwMJrUG4De9FkW_pkpu2EyQQVPM4ShGkQL3-
> Z6E88I0tIjvg/http%3A%2F%2Flug.boulder.co.us
> Mailing List: http://secure-web.cisco.com/1CoNDp9vuMYgxx6Nuj2qUlo5PrNXtZ
> hGlEMJIGXQZzEj96zU7z00FtrvkUPejKbUsLZH5TfDSJTNrzSyFFkbzlw9XM
> 5A0h7z0CrJJP5armBDgqs6mppBeIt86uhot-akoSnrexST3JBvjOLI8y7uYhfVm-
> V2X8KgMX6nzaf-VrZW2vEtwE8He14UH9MxnwJfBcoUZID9lptntVWpGtjEeRDqYEmjj00F67oY
> _BLNvkRz6S4OO9irv31evkK9A60opIQLRDCjNPbrEf79evreMF-
> iK6osOMNaWcBHDfCwKW-mTai_sQM5GzMeQsNqasgDG9MmDE-zzlO_
> KSPuEHRArHTEYtoDSFpBgQVHNDjtEHvQO4q4X0DMW_Usl7u3DtvSOeu7dlIhCtecCM35R8rc
> puubcAhMQQBIK05IhkF8ppcwYnoDszLwrJH-zZL5R7eTGQauMQV_e5E6l_
> FfvrhQX0A/http%3A%2F%2Flists.lug.boulder.co.us%2Fmailman%2Flistinfo%2Flug
> Join us on IRC: irc.hackingsociety.org port=6667 channel=#hackingsociety
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.lug.boulder.co.us/pipermail/lug/attachments/20180313/ce962eab/attachment.html>