HW Raid poor io performance Post: 302461302

Sponsored Content

Top Forums UNIX for Advanced & Expert Users HW Raid poor io performance Post 302461302 by roli8200 on Sunday 10th of October 2010 03:53:43 AM

10-10-2010

Registered User

HW Raid poor io performance

Hello all

We just built a storage cluster for our new xenserver farm. Using 3ware 9650SE raid controllers with 8 x 1TB WD sata disks in a raid 5, 256KB stripe size.

While making first performance test on the local storage server using dd (which simulates the read/write access to the disk mostly equal as the iscsi target does it later) we see very strange performance values.

Using the default dd (with the hardware reported block size of 512bytes) directly on the device (/dev/sdb) gives around 44MB/s write performance.

Using dd with a 1MB blocksize (bs=1M) gives around 587MB/s write performance.

Also the partition alignment makes huge diffrences between 28MB/s and 250MB/s (by 512byte blocksize).

The values are all the same using diffrent linux distros: CentOS, Fedora 13, Ubuntu, SLES.

I know it must have something to do with the stripe size and scheduler settings such as queue_depth and nr_requests, etc. But I can't see the relation between all this settings.

Is there a crack who can give me a little help getting this done? It would be very helpful especially that we work on this issue more than two weeks, read all the available documentations to this topics and the people from 3ware couln't help us yet.

Thanks in advance.

Roland Kaeser

roli8200

View Public Profile for roli8200

Find all posts by roli8200

9 More Discussions You Might Find Interesting

1. UNIX for Advanced & Expert Users

Samba on E3500 Poor Performance!!!

Hi you all, I have a BIG performance problem on an Sun E3500, the scenario is described below: I have several users (30) accessing via samba to the E3500 using an application built on Visual Foxpro from their Windows PC , the problem is that the first guy that logs in demands 30% of the E3500...

2. Filesystems, Disks and Memory

Poor read performance on sun storedge a1000

Hello, i have a a1000 connected to an e6500. There's a raid 10 (12 disks) on the a1000. If i do a dd if=/dev/zero of=/mnt/1 bs=1024k count=1000 and then look at iostat it tells me there's a kw/s of 25000. But if i do a dd of=/dev/zero if=/mnt/1 bs=1024k count=1000 then i see only a...

3. UNIX for Dummies Questions & Answers

poor performance processing file with awk

Hello, I'm running a script on AIX to process lines in a file. I need to enclose the second column in quotation marks and write each line to a new file. I've come up with the following: #!/bin/ksh filename=$1 exec >> $filename.new cat $filename | while read LINE do echo $LINE | awk...

4. Solaris

Poor Disk performance on ZFS

Hello, we have a machine with Solaris Express 11, 2 LSI 9211 8i SAS 2 controllers (multipath to disks), multiport backplane, 16 Seagate Cheetah 15K RPM disks. Each disk has a sequential performance of 220/230 MB/s and in fact if I do a dd if=/dev/zero of=/dev/rdsk/<diskID_1> bs=1024k...

5. Solaris

Poor disk performance however no sign of failure

Hello guys, I have two servers performing the same disk operations. I believe one server is having a disk's impending failure however I have no hard evidence to prove it. This is a pair of Netra 210's with 2 drives in a hardware raid mirror (LSI raid controller). While performing intensive...

6. AIX

Poor Performance of server

Hi, I am new registered user here in this UNIX forums. I am a new system administrator for AIX 6.1. One of our servers performs poorly every time our application (FINACLE) runs many processes/instances. (see below for topas snapshot) I use NMON or Topas to monitor the server utilization. I...

7. Solaris

Poor performance on an M3000

Hi We have an M3000 single physical processor and 8gb of memory running Solaris 10. This system runs two Oracle Databases one on Oracle 9i and One on Oracle 10g. As soon as the Oracle 10g database starts we see an immediate drop in system performance, for example opening an ssh session can...

8. AIX

ISCSI poor performance 1.5MB/s fresh install AIX7.1

Hi Everyone, I have been struggling for few days with iSCSI and thought I could get some help on the forum... fresh install of AIX7.1 TL4 on Power 710, The rootvg relies on 3 SAS disks in RAID 0, 32GB Memory The lpar Profile is using all of the managed system's resources. I have connected...

9. Windows & DOS: Issues & Discussions

Poor Windows 10 Performance of Parallels Desktop 15 on macOS Catalina

Just a quick note for macOS users. I just installed (and removed) Parallels Desktop 15 Edition on my MacPro (2013) with 64GB memory and 12-cores, which is running the latest version of macOS Catalina as of this post. The reason for this install was to test some RIGOL test gear software which...

LEARN ABOUT OPENSOLARIS

si3124

si3124(7D)							      Devices								si3124(7D)

NAME

       si3124 - SiliconImage 3124/3132 SATA controller driver

SYNOPSIS

       sata@unit-address

DESCRIPTION

       The  si3124 driver is a SATA framework-compliant HBA driver that supports Silicon Image 3124 and 3132 SATA controllers. Note that while the
       Silicon Image controllers supports standard SATA features including SATA-II disks, NCQ, hotplug,  port  multiplier  and	ATAPI  disks,  the
       si3124 driver currently does not support NCQ, port multiplier or ATAPI features.

CONFIGURATION

       There are no tunable parameters in the si3124.conf file.

FILES

       /kernel/drv/si3124	   32-bit ELF kernel module (x86).

       /kernel/drv/amd64/si3124    64-bit ELF kernel module. (x86).

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Architecture		     |x86			   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWsi3124		   |
       +-----------------------------+-----------------------------+

SEE ALSO

       cfgadm(1M), prtconf(1M), cfgadm_sata(1M), attributes(5), nv_sata(7D), sata(7D)

       Writing Device Drivers

SunOS 5.11							  17 August 2007							si3124(7D)