[Gluster-users] [SPAM?] Storage Design Overview

Joe Landman landman at scalableinformatics.com
Wed May 11 14:35:48 UTC 2011

On 05/11/2011 10:22 AM, Burnash, James wrote:

Standard disclaimers apply ... we build really fast storage systems and 
storage clusters and have a financial interest in these things, so take 
what we say in this context.

> Answers inline below as well J
> Hope this helps.
> James Burnash, Unix Engineering
> *From:*gluster-users-bounces at gluster.org
> [mailto:gluster-users-bounces at gluster.org] *On Behalf Of *Nyamul Hassan
> *Sent:* Wednesday, May 11, 2011 10:04 AM
> *To:* gluster-users at gluster.org
> *Subject:* Re: [Gluster-users] [SPAM?] Storage Design Overview
> Thank you for the prompt and insightful answer, James. My remarks are
> inline.
>     1.Can we mount a GlusterFS on a client and expect it to provide
>     sustained throughput near wirespeed? <No>
> In your scenario, what were the maximum read speeds that you observed?
>                  Read (using dd) approximately 60MB/sec to 100MB/sec.

Depends upon many things in a long chain ... network performance, local 
stack performance, remote disk performance, etc.

Our experience has been that the cause of a majority of the lower 
performing situations we have observed in self-designed systems, has 
been a significant (often severe and designed in) bottleneck, that 
actively prevents users from achieving anything more than moderate speed.

We have measured up to 700 MB/s for simple dd's over an SDR Infiniband 
network using gluster 3.1.3, and about 500 MB/s over 10GbE.  It is 
achievable, but you have to start with a good design.  Good designs 
aren't buzzword enabled ... there are methods to the madness as it were. 
   This is what we provide to our customer base.

>     3.Does it put extra pressure on the client?<What do you mean by
>     pressure? My clients (HP ProLiant DL360 G5 Quad Core with 32GB RAM)
>     show up to 2GB of memory usage when the native Gluster client is
>     used for mounts – but that is dependent on what you set the client
>     cache max for – in my case, 2GB. CPU utilization is usually
>     negligible in my systems, network bandwidth utilization and I/O
>     throughput … depend on what the files sizes and access patterns look
>     like>

Heavy IO will fill up work queue slots in the kernel.  This is true of 
every file system.

> Thx for the insight. Can you describe your current deployment a bit
> more, like configs of the storage nodes, and the client nodes, and what
> type of application you are using it for? Don't want to be too
> intrusive, just to get an idea on what others are doing.
> All on Gluster 3.1.3

We are also at 3.1.3 in the lab after experiencing problems with 3.1.4 
and 3.2.0.  Have a few bugs filed.

Joseph Landman, Ph.D
Founder and CEO
Scalable Informatics Inc.
email: landman at scalableinformatics.com
web  : http://scalableinformatics.com
phone: +1 734 786 8423 x121
fax  : +1 866 888 3112
cell : +1 734 612 4615

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