>From some graphs I have seen the overhead varies a lot depending on the I/O
>size and if read or write and if random IO or not.
So definitely YMMV.
Remember too that ESS uses powerful processors in order to do the erasure
coding and hence has performance to do checksums too. Traditionally ordinary
NSD servers are merely ‘routers’ and as such are often using low spec cpus
which may not be fast enough for the extra load?
Daniel
Dr Daniel Kidger
IBM Technical Sales Specialist
Software Defined Solution Sales
+ 44-(0)7818 522 266
[email protected]
> On 11 May 2018, at 19:34, Oesterlin, Robert <[email protected]>
> wrote:
>
> Ah be careful! looking at the man page for mmchconfig “nsdCksumTraditional:
>
> https://www.ibm.com/support/knowledgecenter/STXKQY_5.0.1/com.ibm.spectrum.scale.v5r01.doc/bl1adm_mmchconfig.htm
>
> Enabling this feature can result in significant I/O performance degradation
> and a considerable increase in CPU usage.
>
>
> Bob Oesterlin
> Sr Principal Storage Engineer, Nuance
>
>
> From: <[email protected]> on behalf of "Buterbaugh,
> Kevin L" <[email protected]>
> Reply-To: gpfsug main discussion list <[email protected]>
> Date: Friday, May 11, 2018 at 1:29 PM
> To: gpfsug main discussion list <[email protected]>
> Subject: [EXTERNAL] Re: [gpfsug-discuss] FYI, Spectrum Scale 5.0.1 is out
>
> On the other hand, we are very excited by this (from the README):
> File systems: Traditional NSD nodes and servers can use checksums
>
> NSD clients and servers that are configured with IBM Spectrum
> Scale can use checksums
>
> to verify data integrity and detect network corruption of file
> data that the client
>
> reads from or writes to the NSD server. For more information, see
> the
>
> nsdCksumTraditional and nsdDumpBuffersOnCksumError attributes in
> the topic mmchconfig command.
>
> Finally! Thanks, IBM (seriously)…
>
> Kevin
>
>
> On May 11, 2018, at 12:11 PM, Sanchez, Paul <[email protected]> wrote:
>
> I’d normally be excited by this, since we do aggressively apply GPFS
> upgrades. But it’s worth noting that no released version of Scale works with
> the latest RHEL7 kernel yet (anything >= 3.10.0-780). So if you’re also in
> the habit of aggressively upgrading RedHat then you’re going to have to wait
> for 5.0.1-1 before you can resume that practice.
>
> From: [email protected]
> <[email protected]> On Behalf Of Bryan Banister
> Sent: Friday, May 11, 2018 12:25 PM
> To: gpfsug main discussion list ([email protected])
> <[email protected]>
> Subject: [gpfsug-discuss] FYI, Spectrum Scale 5.0.1 is out
>
> It’s on fix central, https://www-945.ibm.com/support/fixcentral
>
> Cheers,
> -Bryan
>
>
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