Increasing Performance of Disc Arrays Post: 302575018

Sponsored Content

Operating Systems Linux Red Hat Increasing Performance of Disc Arrays Post 302575018 by mark54g on Saturday 19th of November 2011 06:44:25 PM

11-19-2011

Registered User

If you are having performance issues, perhaps RAID 5 is a bad choice. Other options might be to check the controller settings to see if you are doing write-through instead of write-back (using the controller's cache or bypassing it).

Another thing to consider is the chunk/stripe size in RAID 5. Depending on workload, it could be an issue. Did you align the file systems so that you are not on a boundary?

Also, even though you have dual RAID 5 arrays, you can and will lose data in a Software RAID 0 system during a failure if you lose 2 drives in an array or part of it becomes inaccessible, as there are parts of the same blocks of data on different parts of the software array. You will have used your disks in the least efficient manner possible.

I suggest you consider RAID 10 for your system if you plan on doing thing this way. Alternately, you may want to check/change your I/O elevator (scheduler), and determine what your most common workload for the disks will be, and then create a setup that will work best in that scenario.

This User Gave Thanks to mark54g For This Post:

mark54g

View Public Profile for mark54g

Find all posts by mark54g

9 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Disc Copy

Is there a disk copy utiliy for unix systems eg: I need to make a duplicate copy of a netraT1 to a netraT1 Thanks

2. UNIX for Dummies Questions & Answers

Copy of HP-UX from MO disc

This is my newbi question. I have HP-UX on a MO drive, need to backup that MO in case of damaging the original. Therefor I need a copy on server and be able to put that copy onto a blank MO to recreate a working bootable disc. This what I did. First I tried to make a copy with dd dd...

3. HP-UX

New MO disc format under HP Unix

How to format new MO disc under HP Unix?

4. UNIX for Dummies Questions & Answers

Disc Needs Maintenance

Hello All Here I am using Sun V880 server which have discsuit pack of 8 discs with 2 sub mirrors each. Everything was fine for the last 1 year. Now I am getting problem of taking backup of the server. After analysis what I got that each 2nd submirrors are in NEEDS MAINTENANCE status. What...

5. News, Links, Events and Announcements

Announcing collectl - new performance linux performance monitor

About 4 years ago I wrote this tool inspired by Rob Urban's collect tool for DEC's Tru64 Unix. What makes this tool as different as collect was in its day is its ability to run at a low overhead and collect tons of stuff. I've expanded the general concept and even include data not available in...

6. UNIX for Dummies Questions & Answers

format disc

What is the best way to format the partition?

7. Solaris

Ultra 10 - Copying Files From Disc After Booting Up With Recovery Disc?

Hello, I'm still learning unix and I have what is probably a simple question but I can't seem to find the question to. I have an Ultra 10 Sparc Server running solaris 8 and the drive may have crashed (I hope not). Currently, it appears some files in the /etc folder are missing. I have a backup...

8. Web Development

PHP arrays in arrays

PHP question... I have an SQL query that's pulled back user IDs as a set of columns. Rather than IDs, I want to use their names. So I have an array of columns $col with values 1,7,3,12 etc and I've got an array $person with values "Fred", "Bert", "Tom" etc So what I want to do is display the...

9. Programming

question about int arrays and file pointer arrays

if i declare both but don't input any variables what values will the int array and file pointer array have on default, and if i want to reset any of the elements of both arrays to default, should i just set it to 0 or NULL or what?

LEARN ABOUT OSX

ataraid

ATARAID(4)						   BSD Kernel Interfaces Manual 						ATARAID(4)

NAME

     ataraid -- ATA software RAID support

SYNOPSIS

     device ata
     device ataraid

DESCRIPTION

     The ataraid driver provides support for so-called software RAID (sometimes referred to as fake RAID or pseudo RAID).

     When a controller that supports software RAID is instructed to create a RAID array, its BIOS writes data structures in a specific metadata
     format to the disks.  These data structures are picked up by the ataraid driver, so that FreeBSD can work with the array.	The ataraid driver
     has to understand the specific metadata format of a controller BIOS in order to support its RAID capabilities.

     Read-only support for a metadata format means that FreeBSD can use the given RAID array for normal read/write operations.	Creation and
     rebuild of such arrays has to be done from the controller BIOS.

     Read and write support for a metadata format means that FreeBSD can use the given RAID array for normal read/write operations.  Additionally,
     the atacontrol(8) utility can be used to create, rebuild, update and fail such RAID arrays.

     The ataraid driver can read the following metadata formats:

     o	 Adaptec HostRAID
     o	 Highpoint V2 RocketRAID
     o	 Highpoint V3 RocketRAID
     o	 Intel MatrixRAID
     o	 Integrated Technology Express (ITE)
     o	 JMicron
     o	 LSI Logic V2 MegaRAID
     o	 LSI Logic V3 MegaRAID
     o	 NVIDIA MediaShield
     o	 Promise FastTrak
     o	 Silicon Image Medley
     o	 Silicon Integrated Systems (SiS)
     o	 VIA Tech V-RAID
     o	 FreeBSD PseudoRAID

     The ataraid driver can write the following metadata formats:

     o	 Highpoint V2 RocketRAID
     o	 Intel MatrixRAID
     o	 JMicron
     o	 Promise FastTrak
     o	 Silicon Integrated Systems (SiS)
     o	 VIA Tech V-RAID
     o	 FreeBSD PseudoRAID

     It is also possible to use software RAID on controllers that do not have special software RAID capabilities.  See atacontrol(8) for details.

FILES

     /dev/ar*  ATA RAID device nodes

SEE ALSO

     ata(4), atacontrol(8)

CAVEATS

     RAID5 is not supported at this time.  Code exists, but it neither uses nor maintains parity information.

AUTHORS

     The ataraid driver was written by Soren Schmidt <sos@FreeBSD.org>.  This manual page was written by Christian Brueffer
     <brueffer@FreeBSD.org>.

BSD
								 February 17, 2006							       BSD