Re: Direct NFS and ZS3
Date: Thu, 7 May 2015 11:27:20 -0400
Message-ID: <CAAaXtLDy2B2odxF+35UCR_ObPMUtzPBhF3YmSoF8O9MnkeF-Mg_at_mail.gmail.com>
It would be interesting to compare dNFS to iSCSI-with-a-TOE-card.
Which is going to offload more burden from the database server's CPUs, I wonder? I'm pretty sure I have never seen any analysis on this.
On Thu, May 7, 2015 at 1:07 AM, Mladen Gogala <dmarc-noreply_at_freelists.org> wrote:
> On 05/06/2015 03:02 PM, Kevin Jernigan wrote:
>
>> Mldaen,
>>
>> The primary design goal for Direct NFS (dNFS) was / is to provide
>> SAN-equivalent (or better) performance, in terms of both latency and
>> throughput, while using NFS / Ethernet infrastructure. A secondary goal is
>> to simplify the configuration and tuning process for Oracle Database with
>> NFS storage. dNFS accomplishes these goals by implementing the NFS client
>> inside Oracle Database, rather then using the OS-supplied "kernel" NFS
>> client. This allows dNFS to skip some parts of the networking stack, and to
>> skip some of functionality that is required for a general-purpose NFS
>> client, such as write ordering. In addition, dNFS creates a separate
>> connection to the NFS server for each Oracle process, unlike kNFS, which
>> essentially multiplexes all the processes' I/O's through one or a very
>> small number of connections to the NFS server. There are other
>> optimizations in dNFS which provide major performance improvements over
>> kNFS, and which allow dNFS to auto-configure itself based on interrogating
>> the NFS server.
>>
>
> Well, I'll have to check it out then. I was lazy and was simply using
> /etc/exports and put the nfs4 mount with the corresponding options into
> /etc/fstab and that was about it. So far, I used kNFS because I know how
> to configure it and have been using it for a long, long time. Usually, I
> didn't have much trouble with it, if the connection was fast enough. 10GB
> LAN is the norm for NFS based DB.
>
>
>> In general, if the NFS server can handle the workload, then dNFS can
>> provide SAN or iSCSI-equivalent performance, with very little configuration
>> work required of the DBA or system administrator.
>>
>
> In my experience, NFS provides better performance than iSCSI without a
> specialized HBA. As I have said, I don't have numbers, just impressions.
>
>
> --
> Mladen Gogala
> Oracle DBA
> http://mgogala.freehostia.com
>
> --
> http://www.freelists.org/webpage/oracle-l
>
>
>
-- http://www.freelists.org/webpage/oracle-lReceived on Thu May 07 2015 - 17:27:20 CEST