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RAID 5 or RAID 10?

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September 17, 2009 11:38:57 AM

I am running a workstation appz with lots of I/O & bandwidth, i.e. digital audio/video recording/editing, what RAID configurations would be best?

I am leaning to RAID10 (4 HDs) over RAID5 (3 or 4 HDs)?

If i am using a hardware RAID PCIe card, are the cheaper 7200 3GBs SATA HDs fast enough? do the super fast 10K nor 15K HD buy much performance with my type application?

thanks,
billy

More about : raid raid

September 17, 2009 12:11:59 PM

http://www.buzzle.com/articles/raid5-vs-raid10.html

RAID 5 Vs. RAID 10

There is often a comparison between RAID 5 and RAID 10 and a debate on the difference between RAID 5 and RAID 10. This article has thus been written, to present the RAID 5 vs RAID 10 comparison. But before we start with the RAID 5 vs RAID 10 comparison, we need to know what is RAID?
RAID 5 vs RAID10
Data Loss and Data Recovery
Let us start off by having RAID 5 explained. In RAID 5, the data backup of any one of the disks is created. If there are 5 disks, in the storage system, then 4 of the disks will be used for storing the data and one of the disks will be used for keeping the backup of any one of the hard disks. If one of the disks in the array fails, then the data can be recovered, but in the event of a second disk failure, the recovery is not possible. RAID 10 on the other hand is a combination of RAID 0 and RAID 1. In a RAID 10 storage scheme, an even number of disks is required. Each disk array has a disk array, which is a mirrored set of the former. In RAID 10, data recovery of all but one disk can be performed. In the case of a disk failure, all the remaining disks can be used effectively without any impact on the storage scheme.

Performance
The RAID 5 performance in the read operations is quite appreciated, though its write operation is quite slow, as compared to RAID 10. RAID 10 is thus used for systems which require high write performance. Hence, it is very obvious, RAID 10 is not used for systems like heavy databases, which require high speed write performance.

Redundancy
The RAID 10 arrays are more data redundant than the RAID 5 arrays. This makes RAID 10 an ideal option for the cases where high data redundancy is required.

Architectural Flexibility
RAID 10 provides more architectural flexibility, as compared to RAID 5. The amount of free space left is also minimized, if you use a RAID 10 data storage scheme.

Controller Requirement
RAID 5 demands a high end card for the data storage performance. If the purpose of the RAID 5 controller is being solved by the operating system, then it will result in the slowing down of the performance of the computer. In case of a RAID 10 controller, any hardware controller can be used.

Applications
RAID 10 finds a wide variety of applications. Systems with RAID 0, RAID 1 or RAID 5 storage schemes are often replaced with a RAID 10 storage scheme. They are mainly used for medium sized databases. RAID 5 disks are primarily used in the processes that require transactions. Relational databases are among the other fields that run very well under a RAID 5 storage scheme.

also http://www.tomshardware.co.uk/forum/page-244551_14_0.ht...
a c 415 G Storage
September 17, 2009 5:43:54 PM

To boil it down to simple terms: RAID 0+1 is superior to RAID 5 in performance (especially write performance) and reliability (particularly with 4 or more disks). It's only drawback is that is has less capacity.

High speed drives will give better performance than ordinary drives even in a RAID array. The question isn't whether they'll be faster, it's whether or not the performance in a RAID array with just standard drives will be good enough. My guess is that with a 4-drive RAID 0+1 it probably would be, but it really depends on how hard you're pushing the system. Video editing can be very demanding.
Related resources
a c 415 G Storage
September 17, 2009 5:44:23 PM

sirkillalot said:
Hence, it is very obvious, RAID 10 is not used for systems like heavy databases, which require high speed write performance.
This is a typo, they should mean "RAID 5 is not used for ... databases".
September 17, 2009 10:45:05 PM

are you familiar with the HighPoint RR4320? it is a Hardward RAID PCIe card. it can most any RAID config but it mentions it's great hardware performance with RAID5 and RAID6 which i am not sure why it's high-lighted!

RAID5 vs RAID6? it still seems like RAID 10 is the one to use for high write & read apps. again i am planning to use 4 HDs if needed to do it right.

do you are anyone have time to check-out the RR4320 card and give me your opinion on that card? i just got the cad today and have NOT purchased any HDs YET! i want to do it right this time!

suggestions needed before i move on to buying the (4) HDs. i found 4 refurbished Futijsu MAX SAS 15k 3GB/s 16Mb cache (not made anymore) HDs for a good price (i can get the 150 Gb version for $85.00 each). good deal i guess.

sincere thanks,
billy
September 17, 2009 11:34:06 PM

7200 SATA dirve = 30 - 80 IOPS
10k SCSI/SAS = 140 IOPS
15k SCSI/SAS = 180 IOPS
(actual IOPS vary by make model, blah blah blah...)


raid 10:
read = 1 IOPS
write = 2 IOPs (mirroring write penatly)

raid 5
read = 1 IOPS
write = 4 IOPS(parity write penatly)

do the math, find out how many IOPS you require for you application.
a c 167 G Storage
September 17, 2009 11:38:38 PM

How much do you need the hard drive protection capabilities of raid?
The value of raid-1 and it's variants like raid-5 for protecting data is that you can recover from a hard drive failure quickly.
It is for servers that can't afford any down time.
Recovery from a hard drive failure is just moments.
Fortunately hard drives do not fail often.
Mean time to failure is claimed to be on the order of 1,000,000 hours.(100 years)
Raid-1 does not protect you from other types of losses such as viruses,
software errors,raid controller failure, operator error, or fire...etc.
For that, you need EXTERNAL backup.
If you have external backup, and can afford some recovery time, then you don't need raid-1 or...

Perhaps for sequential operations, you might be better served by a couple of simple raid-0 striped arrays.

As to the speed of hard drives, there is not much difference in sequential speed with most 7k, 10k, or 15k drives. The rotation rate does not translate directly into how fast the drive can transfer data. The faster rotation rate does directly improve the positioning or access time of the drive. Look in the drive's spec sheet to find the maximum continuous data transfer rate. The fastest rates usually come with the larger, denser drives.



a c 415 G Storage
September 18, 2009 6:39:43 AM

GrievousAngel said:
are you familiar with the HighPoint RR4320? it is a Hardward RAID PCIe card. it can most any RAID config but it mentions it's great hardware performance with RAID5 and RAID6 which i am not sure why it's high-lighted!
Not familiar with the card. Raid 5/6 by their very nature have very poor write performance. Some cards use caching and other techniques to overcome this, and so I suspect their claim of high performance means "high performance (considering it's RAID 5)" and not "high performance (compared to RAID 1)". In other words, RAID 1 or 0+1 is still going to beat RAID 5 or 6 by a long shot in terms of write performance.
a c 415 G Storage
September 18, 2009 6:43:07 AM

spinning rust said:
7200 SATA dirve = 30 - 80 IOPS
10k SCSI/SAS = 140 IOPS
raid 10:
read = 1 IOPS
write = 2 IOPs (mirroring write penatly)
raid 5
read = 1 IOPS
write = 4 IOPS(parity write penatly)
I assume "IOPS" = "IO operations/sec"? Where the heck do these numbers come from? There's no way that bare drives can beat RAID arrays in performance, and there's no way that RAID 5 can have 4X better write performance than read performance.
a c 415 G Storage
September 18, 2009 6:45:58 AM

geofelt said:
Raid-1 does not protect you from other types of losses such as viruses,
software errors,raid controller failure, operator error, or fire...etc.
For that, you need EXTERNAL backup.
If you have external backup, and can afford some recovery time, then you don't need raid-1 or...
This is a very important point! Grievous, if you're going to buy 4 drives and haven't allowed for external backup, you're probably better off deploying 2 of those drives for external backup than for online use in your RAID array, assuming you don't want to loose your data.

Best practice for backups: you should have two OFFLINE copies copies of your data, and one of those copies should be OFFSITE.
September 18, 2009 8:42:14 AM

'In other words, RAID 1 or 0+1 is still going to beat RAID 5 or 6 by a long shot in terms of write performance.'

above: did you meant to say RAID0 not RAID1? RAID0 correct.

billy
September 18, 2009 8:49:46 AM

sminlal said:
This is a very important point! Grievous, if you're going to buy 4 drives and haven't allowed for external backup, you're probably better off deploying 2 of those drives for external backup than for online use in your RAID array, assuming you don't want to loose your data.

Best practice for backups: you should have two OFFLINE copies copies of your data, and one of those copies should be OFFSITE.


i have an extra Port 2 on the RR4320 OR i could use the eSATA port on the mobo, so 'local backup' is certainly in reach and needed.

the extra Port 2 on the RR4320 brings up another question - should build a 2nd RAID on Port 2? i do not want to build RAIDs just for building RAIDs but if it buys me performance and safer data then . . . .

thnaks.

billy
September 18, 2009 8:58:56 AM

since some of this thread mentions my RR4320, i thought i would post the RR4320 specs for others to read:

HighPoint Products -> SAS Series -> RocketRAID 4320


Host Adapter Architecture
Intel IOP348 (1.2GHz)
Up to 256MB DDR-II Memory
PCI-Express x8
2 internal mini-SAS/SATA 3Gb/s Device connectors
Up to 8 SAS/SATA Hard Drives 128 max hard drives via SAS expanders
NCQ (Native Command Queuing)
NVRAM
Battery Backup Unit Ready (BBU-03)
Low Profile
Supported RAID Feature
RAID Levels 0, 1, 3, 5, 6, 10, 50 and JBOD Multiple RAID Support
Online Array Roaming
Automatic RAID Rebuild
Automatic Drive Insertion
Quick Initialization
Online Capacity Expansion / Online RAID Level Migration
Hot Spare - (global)
Configurable stripe size
Staggered Drive Spin-up

Bad Sector Repair and Remapping
BIOS Booting Support
HighPoint RAID Management (HRM) Suite
Web GUI management utility
CLI (Command Line Interface)
Firmware / BIOS Management
Independent RAID Module Onboard
Monitor, Alert & Indicator
SMTP (Email Notification)
(Hard drive activity and failure) LED
SAF-TE chassis environment monitoring
Operating System Support
Microsoft® Windows® 2008/2003/XP/ 2000/x64 Edition/Vista 32 and 64 bit
Red Hat Enterprise Linux, Open SuSE, Fedora Core, Debian
FreeBSD
Mac OS X
Linux Open Source Drivers
Native Support in Linux kernel 2.6.25
September 18, 2009 11:35:48 AM

thanks for the link.

yes i did read that before buying the unit.

later,
billy
a c 415 G Storage
September 18, 2009 4:37:31 PM

GrievousAngel said:
'In other words, RAID 1 or 0+1 is still going to beat RAID 5 or 6 by a long shot in terms of write performance.'

above: did you meant to say RAID0 not RAID1? RAID0 correct.


Basically any other RAID organization beats RAID 5 or 6 for write performance. RAID 1 has to update two disks during a write, but it can write to both disks in parallel so there's not that much performance cost. For RAID 5, you have to read the old data FIRST, THEN write the new data and parity. There's no way to do the operations in parallel, so the write performance is always at least twice as bad. Caching can help to some degree if the writes are localized, but in the real world there's no way it can keep up with the other RAID configurations.

So in terms of write performance, RAID 0 is best, then plain old disks, then (by a small margin) RAID 1, then (by a wide margin) RAID 5.
July 28, 2013 8:23:41 AM

hello and good day
do you have articles that include this information?
I need references for this matter. is there any chance that I give your articles (comparison between raid 5 and raid 10)?
I would appreciate your helping
my email: hasaniasal@yahoo.com


sirkillalot said:
http://www.buzzle.com/articles/raid5-vs-raid10.html

RAID 5 Vs. RAID 10

There is often a comparison between RAID 5 and RAID 10 and a debate on the difference between RAID 5 and RAID 10. This article has thus been written, to present the RAID 5 vs RAID 10 comparison. But before we start with the RAID 5 vs RAID 10 comparison, we need to know what is RAID?
RAID 5 vs RAID10
Data Loss and Data Recovery
Let us start off by having RAID 5 explained. In RAID 5, the data backup of any one of the disks is created. If there are 5 disks, in the storage system, then 4 of the disks will be used for storing the data and one of the disks will be used for keeping the backup of any one of the hard disks. If one of the disks in the array fails, then the data can be recovered, but in the event of a second disk failure, the recovery is not possible. RAID 10 on the other hand is a combination of RAID 0 and RAID 1. In a RAID 10 storage scheme, an even number of disks is required. Each disk array has a disk array, which is a mirrored set of the former. In RAID 10, data recovery of all but one disk can be performed. In the case of a disk failure, all the remaining disks can be used effectively without any impact on the storage scheme.

Performance
The RAID 5 performance in the read operations is quite appreciated, though its write operation is quite slow, as compared to RAID 10. RAID 10 is thus used for systems which require high write performance. Hence, it is very obvious, RAID 10 is not used for systems like heavy databases, which require high speed write performance.

Redundancy
The RAID 10 arrays are more data redundant than the RAID 5 arrays. This makes RAID 10 an ideal option for the cases where high data redundancy is required.

Architectural Flexibility
RAID 10 provides more architectural flexibility, as compared to RAID 5. The amount of free space left is also minimized, if you use a RAID 10 data storage scheme.

Controller Requirement
RAID 5 demands a high end card for the data storage performance. If the purpose of the RAID 5 controller is being solved by the operating system, then it will result in the slowing down of the performance of the computer. In case of a RAID 10 controller, any hardware controller can be used.

Applications
RAID 10 finds a wide variety of applications. Systems with RAID 0, RAID 1 or RAID 5 storage schemes are often replaced with a RAID 10 storage scheme. They are mainly used for medium sized databases. RAID 5 disks are primarily used in the processes that require transactions. Relational databases are among the other fields that run very well under a RAID 5 storage scheme.

also http://www.tomshardware.co.uk/forum/page-244551_14_0.ht...


a b G Storage
July 29, 2013 3:30:47 PM

GrievousAngel said:
thanks for the link.

yes i did read that before buying the unit.

later,
billy


Billy - Your RAID has only 4x Drives
It rather fast to create RAID5 and RAID10. Within minute RAID volume will be created (use option NO INI)
Run some test with IOmeter It will tell you how many I/O you can get from RAID10 vs RAID5

Not every RAID engines are the same
!