Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: HW Raid poor io performance
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
Old 10-10-2010
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
 

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 Replies)
Discussion started by: alex blanco
2 Replies

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... (1 Reply)
Discussion started by: mbrenner
1 Replies

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... (2 Replies)
Discussion started by: scooter53080
2 Replies

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... (1 Reply)
Discussion started by: golemico
1 Replies

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... (4 Replies)
Discussion started by: s ladd
4 Replies

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... (9 Replies)
Discussion started by: guzzelle
9 Replies

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... (6 Replies)
Discussion started by: gregsih
6 Replies

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... (11 Replies)
Discussion started by: frenchy59
11 Replies

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... (6 Replies)
Discussion started by: Neo
6 Replies

LEARN ABOUT OPENSOLARIS

mega_sas

mega_sas(7D)							      Devices							      mega_sas(7D)

NAME

       mega_sas - SCSI HBA driver for LSI MegaRAID SAS controller

DESCRIPTION

       The mega_sas MegaRAID controller host bus adapter driver  is a  SCSA-compliant  nexus  driver that supports the Dell PERC 5/E, 5/i, 6/E and
       6/i RAID controllers, the IBM ServeRAID-MR10k SAS/SATA  controller and  the  LSI  MegaRAID  SAS/SATA  8308ELP,  8344ELP,  84016E,  8408ELP,
       8480ELP, 8704ELP, 8704EM2, 8708ELP, 8708EM2, 8880EM2 and 8888ELP series of controllers.

       Supported  RAID	features  include RAID levels 0, 1, 5, and 6, RAID spans 10, 50 and 60, online capacity expansion (OCE), online RAID level
       migration (RLM), auto resume after loss of  system power during arrays, array rebuild or reconstruction (RLM) and configurable stripe  size
       up  to  1MB. Additional supported RAID features include check consistency for background data integrity, patrol read for media scanning and
       repairing, 64 logical drive support, up to 64TB LUN support, automatic rebuild and global and dedicated hot spare support.

CONFIGURATION

       The mega_sas.conf file contains no user configurable parameters. Please configure your hardware through the related  BIOS  utility  or  the
       MegaCli	configuration  utility.  If  you  want to install to a drive attached to a mega_sas HBA, you should create the virtual drive first
       from the BIOS before running the Solaris install. You can obtain the MegaCli utility from the LSI website.

       The mega_sas device can support up to  64 virtual disks. Note that BIOS numbers the virtual disks as 1 through 64, however in  the  Solaris
       operating  environment virtual disks are numbered from 0 to 63.	Also note that SAS and SATA drives cannot be configured into the same vir-
       tual disk.

KNOWN PROBLEMS AND LIMITATIONS

       The mega_sas driver does not support the LSI MegaRAID SAS 8204ELP, 8204XLP, 8208ELP, and 8208XLP controllers.

FILES

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

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

       /kernel/drv/mega_sas.conf     Driver configuration file (contains no user-configurable options).

ATTRIBUTES

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

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Architecture		     |x86-based systems 	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWmegasas		   |
       +-----------------------------+-----------------------------+
       |Interface stability	     |Uncommitted		   |
       +-----------------------------+-----------------------------+

SEE ALSO

       prtconf(1M), attributes(5), sata(7D), scsi_hba_attach_setup(9F), scsi_sync_pkt(9F), scsi_transport(9F), scsi_inquiry(9S),  scsi_device(9S),
       scsi_pkt(9S)

       Small Computer System Interface-2 (SCSI-2)

SunOS 5.11							    14 Aug 2008 						      mega_sas(7D)
All times are GMT -4. The time now is 04:50 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy