thank for your ideas,

I have measure the OST RAID performance, and there isn’t a bottleneck in the 
RAID disk. If I write directly in the RAID I got:

dd if=/dev/zero of=test.dat bs=1M count=1000
1000+0 records in
1000+0 records out
1048576000 bytes (1,0 GB) copied, 1,34852 s, 778 MB/s

And If i use /dev/urandom as input file I get the same performance again for 
infiniband and ethernet connection.

How can I write directly forgoing cache?


Thanks again!




El 19/05/2014, a las 13:24, Hammitt, Charles Allen <chamm...@email.unc.edu> 
escribió:

> Two things:
> 
> 1)  Linux write cache is likely getting in the way; you'd be better off 
> trying to write directly forgoing cache
> 2)  you need to write a much bigger file than 1GB; try 50GB
> 
> 
> Then as the previous poster said, maybe your disks aren't up to snuff or are 
> misconfigured.  
> Also, very interesting, and impossible, to get 154MB/s out of a Single GbE 
> link [128MB/s].  Should be more like 100-115.  Less this is 10/40GbE...if 
> so... again, start at #1 and #2.
> 
> 
> 
> 
> Regards,
> 
> Charles
> 
> 
> 
> 
> -- 
> ===========================================
> Charles Hammitt
> Storage Systems Specialist
> ITS Research Computing @ 
> The University of North Carolina-CH
> 211 Manning Drive
> Campus Box # 3420, ITS Manning, Room 2504  
> Chapel Hill, NC 27599
> ===========================================
> 
> 
> 
> 
> -----Original Message-----
> From: lustre-discuss-boun...@lists.lustre.org 
> [mailto:lustre-discuss-boun...@lists.lustre.org] On Behalf Of Vsevolod 
> Nikonorov
> Sent: Monday, May 19, 2014 6:54 AM
> To: lustre-discuss@lists.lustre.org
> Subject: Re: [Lustre-discuss] Same performance Infiniband and Ethernet
> 
> What disks do your OSTs have? Maybe you have reached your disk performance 
> limit, so Infiniband gives some speedup, but very small. Did you try to 
> enable striping on your Lustre filesystem? For instance, you can type 
> something like this: "lfs setstripe -c <count of stripes> 
> /mnt/lustre/somefolder" and than copy a file into that folder.
> 
> Also, there's an opinion that sequence of zeros is not a good way to test a 
> performance, so maybe you should try using /dev/urandom (which is rather 
> slow, so it's better to have a pre-generated "urandom" file in /ram, or 
> /dev/shm, or where your memory space is mounted to, and copy that file to 
> Lustre filesystem as a test).
> 
> 
> 
> Pardo Diaz, Alfonso писал 2014-05-19 14:33:
>> Hi,
>> 
>> I have migrated my Lustre 2.2 to 2.5.1 and I have equipped my OSS/MDS 
>> and clients with Infiniband QDR interfaces.
>> I have compile lustre with OFED 3.2 and I have configured lnet module
>> with:
>> 
>> options lent networks=“o2ib(ib0),tcp(eth0)”
>> 
>> 
>> But when I try to compare the lustre performance across Infiniband 
>> (o2ib), I get the same performance than across ethernet (tcp):
>> 
>> INFINIBAND TEST:
>> dd if=/dev/zero of=test.dat bs=1M count=1000
>> 1000+0 records in
>> 1000+0 records out
>> 1048576000 bytes (1,0 GB) copied, 5,88433 s, 178 MB/s
>> 
>> ETHERNET TEST:
>> dd if=/dev/zero of=test.dat bs=1M count=1000
>> 1000+0 records in
>> 1000+0 records out
>> 1048576000 bytes (1,0 GB) copied, 5,97423 s, 154 MB/s
>> 
>> 
>> And this is my scenario:
>> 
>> - 1 MDs with SSD RAID10 MDT
>> - 10 OSS with 2 OST per OSS
>> - Infiniband interface in connected mode
>> - Centos 6.5
>> - Lustre 2.5.1
>> - Striped filesystem “lfs setstripe -s 1M -c 10"
>> 
>> 
>> I know my infiniband running correctly, because if I use IPERF3 
>> between client and servers I got 40Gb/s by infiniband and 1Gb/s by 
>> ethernet connections.
>> 
>> 
>> 
>> Could you help me?
>> 
> 
>> 
>> Regards,
>> 
>> 
>> 
>> 
>> 
>> Alfonso Pardo Diaz
>> System Administrator / Researcher
>> c/ Sola nº 1; 10200 Trujillo, ESPAÑA
>> Tel: +34 927 65 93 17 Fax: +34 927 32 32 37
>> 
>> 
>> 
>> 
>> ----------------------------
>> Confidencialidad:
>> Este mensaje y sus ficheros adjuntos se dirige exclusivamente a su 
>> destinatario y puede contener información privilegiada o confidencial.
>> Si no es vd. el destinatario indicado, queda notificado de que la 
>> utilización, divulgación y/o copia sin autorización está prohibida en 
>> virtud de la legislación vigente. Si ha recibido este mensaje por 
>> error, le rogamos que nos lo comunique inmediatamente respondiendo al 
>> mensaje y proceda a su destrucción.
>> 
>> Disclaimer:
>> This message and its attached files is intended exclusively for its 
>> recipients and may contain confidential information. If you received 
>> this e-mail in error you are hereby notified that any dissemination, 
>> copy or disclosure of this communication is strictly prohibited and 
>> may be unlawful. In this case, please notify us by a reply and delete 
>> this email and its contents immediately.
>> ----------------------------
>> 
>> _______________________________________________
>> Lustre-discuss mailing list
>> Lustre-discuss@lists.lustre.org
>> http://lists.lustre.org/mailman/listinfo/lustre-discuss
>> 
>> Email secured by Check Point
> 
> --
> Никоноров Всеволод Дмитриевич, ОИТТиС, НИКИЭТ
> 
> Vsevolod D. Nikonorov, JSC NIKET
> 
> Email secured by Check Point
> _______________________________________________
> Lustre-discuss mailing list
> Lustre-discuss@lists.lustre.org
> http://lists.lustre.org/mailman/listinfo/lustre-discuss
> _______________________________________________
> Lustre-discuss mailing list
> Lustre-discuss@lists.lustre.org
> http://lists.lustre.org/mailman/listinfo/lustre-discuss

_______________________________________________
Lustre-discuss mailing list
Lustre-discuss@lists.lustre.org
http://lists.lustre.org/mailman/listinfo/lustre-discuss

Reply via email to