What is better a raid configuration or single disks working in an edius sp system?

[mikemachine]

Hi there, i read some posts that tell that they have a raid system for their HDDs, is it recomendable or it is the same to have all the disks working as single and individual disks?

We have some experience in working with raid systems, we have two Matrox working in our company and they used to have the SCSII discs arranged in raid but one of the discs faile and draged the good one loosing the hole information. That is why we assumed that for the new EDIUS we bought it would be better to have single disks working.

Any suggestion?

[pjsssss]

If you are working with HD footage it would be better to use a RAID. There are several RAID configurations that will allow for safety and backup if one of the discs fail so that you will not lose all of your information. I won't repeat all of them but if you do a general search on RAIDS you will find the info.

BTW no need to "shout"

[mikemachine]

thanks for the answer and sorry for the "shouting"

[swsw1550]

Some different types of raid and a bit on how it works, I hope this helps you a bit,
RAID 0
RAID 0 is also called striping and treats two or more physical drives as one large drive. This style of RAID provides no redundancy, however it does provide speed advantages. If you installed two 80Gb drives configured as RAID 0, your PC would see this as one 160Gb drive going almost twice as fast as a single drive. The reason for this is because the data is read from both physical drives simultaneously.

RAID 1
RAID 1 is also called mirroring. In this configuration, the RAID controller keeps identical copies of the data on each drive. If one drive fails, you have a copy of the information on the other drive. When the failed drive is replaced, your RAID controller will copy the information back such that your redundancy is restored. There is no speed boost with RAID 1, the advantage is redundancy.

RAID 5
RAID 5 is the deluxe option. It is not supported by all controllers so it is important to confirm it is supported when reviewing controller options. RAID 5 uses a minimum of three drives; however the number can be as many as eight or more for larger implementations. RAID 5 looks at the data on all the drives and uses this detail to calculate a checksum. The checksum is stored as an overhead to the data such that if any single drive fails, the array can be rebuilt by recalculating the data based on the checksums. RAID 5 provides excellent performance by supplying the speed of many drives reading and writing simultaneously, combined with checksum redundancy. Your effective drive capacity is calculated by the number of drives in the array minus 1. e.g. 5 x 80GB drives in RAID 5 will give you 320 GB.

Mix’n’match your RAID
You can combine different RAID configurations in order to gain advantages from the various RAID types. For example, you could combine RAID 1 and 0 to get both speed and redundancy ie RAID 10. In this example, if you used 4 X 80Gb drives to get a logical 80Gb drive, it would provide twice the speed of a single drive layered with redundancy. If any single drive fails, simply replace it and continue working. There will be no data loss or need to restore as two of the drives will be holding a mirror image of the other two. Choosing which RAID types to mix can be complex as there are many technical considerations.

RAID 5 is the most common RAID implementation for servers, however if you are seeking additional performance and redundancy, you can use RAID 50 which combines two arrays of RAID 5 striped with RAID 0 to provide additional performance.

Cheers
Steve

[antonsvideo]

Some different types of raid and a bit on how it works, I hope this helps you a bit,
RAID 0
If you installed two 80Gb drives configured as RAID 0, your PC would see this as one 80Gb drive going almost twice as fast as a single drive

you mean 160GB drive going almost twice as fast

I have 4 x 1GB Sata in Raid0 and they are doing 420mb/sec

a single 1GB sata does 105mb/sec

[swsw1550]

Sorry Anton I was still half asleep when I posted this, fixed now.

Steve

[GrassValley_BH]

ACNC has a great RAID tutorial on their website.

Remember that while striped arrays help increase data throughput, striping doesn't eliminate seek time latencies it just reduces its effect since the throughput is increased.

So if you're working with a large number of clips simultaneously, sometimes it's better to go with single (physical) disks and distribute the clips across those disks to minimize seek times.

[DaveG]

to help me avoid enflaming anyone at any time - what did the "shouting" refer too please?

If you are working with HD footage it would be better to use a RAID. There are several RAID configurations that will allow for safety and backup if one of the discs fail so that you will not lose all of your information. I won't repeat all of them but if you do a general search on RAIDS you will find the info.

BTW no need to "shout"

[Rusty]

to help me avoid enflaming anyone at any time - what did the "shouting" refer too please?

YOU MEAN SHOUTING???
Probably had the caps-lock on... obviously edited the post.

[pjsssss]

to help me avoid enflaming anyone at any time - what did the "shouting" refer too please?

Yes, typing with all caps is consideried shouting.

[DaveG]

Thanks, will ensure I don't either...

[skier-hughes]

My 2 x 1TB mirrored raid system rebuilds itself if the pc is turned off then back on.
This "may" be a reason why I sometimes have disc too slow messages. I'm still working on testing the theory.

[redgum]

ACNC has a great RAID tutorial on their website.

So if you're working with a large number of clips simultaneously, sometimes it's better to go with single (physical) disks and distribute the clips across those disks to minimize seek times.

Brandon, can you explain how this works in reality?
For instance, if I have 20 HDV clips on a typical Edius timeline and I progressively add filters to each one, are you saying it's better to have single drives rather than Raid?
Or are you talking about overlays, say 3 clips stacked on top of each other with opacity or other filters/transitions?
With all the reviews I've done on Edius and Adobe I can never get single (multiple) drives to work faster than a Raid 0.

[Ron Evans]

A two disc RAID 0 is about 1.7 times the speed of a single disc for a single operation. So reading or writing to the array will be 1.7 times faster than a single disc. However if one only has this one array for all storage and editing then it will be slower than separate discs since reading and writing to the same array will be at a disadvantage in the proportion of 1.7 to 2. That is about 15% slower than reading from one disc and writing to another. In practice it is even slower because of fragmentation and seek times that will be twice those for single discs. Each file is broken up into pieces and written alternately to each drive in the array. A single contiguous file on a single drive will readout with minimal seeks of the head. A RAID has to seek each of these pieces and assemble to form the files hence the faster read performance but not quite twice( for a two disc array) since files have to be assembled and for a software RAID robs CPU time too. Adding more discs dramatically increases performance and the vulnerability since now any disc failure looses everything!!! Personally I do not use a RAID for the things I do ( mainly multicam of two FX1's native HDV and SR11 AVCHD converted to HQ). Files are spread over three drives and output to a fourth( or the drive with the SR11 files as these are not used a lot in the final edit) with another dedicated to temp storage for the programs that are able to use a separate drive for temp/scratch files. All these drives show between 50 and 100MBps and for HDV or HQ files are between 10 and 20 times the needed performance. Project files( Edius default, are on the Temp drive and these is backed up to the Boot drive( the opposite also being true whole Boot backed up to Temp drive, minus the project files of course). I have seen little need to go to a RAID with its complexity and vulnerabilities for the things I do. All my performance monitoring still shows the CPU as being the bottleneck for operating performance. Vegas and Adobe are considerably faster by dedicating the scratch discs and source and render discs appropriately. IF it were a business rather than a hobby for me I may be inclined to use a RAID controller in RAID 5 for both storage and another RAID 5 for final output to make administration a lot easier and not have to bother so much about allocation, performance or redundancy.
Ron Evans

[zb21]

Speaking of files fragmentation....

Since I only work with AVCHD files in HD, I did notice, that AVCHD Converter creates ENORMOUSLY FRAGMENTED FILES during AVCHD -> HQ conversion. If you convert multiple files at the same time the Converter fires up to four threads, each converting separate file concurrently. So, there is four files being written to the hard drive at the same time. The Converter does not seem to allocate the neccessary (approximate) file space for each file at the beginning of the converstion. It just seem to write each file to the disk in small chunks as they are being spitted out of the conversion engine. This leads to converted files interlaced in thousands of chunks. What I do to go around this problem is I convert files to a separate partition, which is solely used for the purpose of storing intermediate files. After Conversion I simply move this highly fragmented files to my 'working' partition. Since the files are copied by Windows in one-by-one sequence, this process eliminates vaste majority of fragmentation and improves general editing performance and 'disk to slow' type of problems.

As far as my configuration - I do use five hard drives with no RAID, RAID 0 and RAID 1 in my computer.
My current board is ASUS P5Q Pro, which has ICH10R RAID controller on it and additional MARVELL disk controller, which I use as boot, no RAID.

I have boot system drive (500GB SATA) connected through MARVELL controller, no RAID here. RAID is usually a problem on a boot drive. No big loss if I loose system drive since it is easy to restore from disk image. 60 GB for Windows is enough, the rest is above mentioned SCRATCH drive for intermediate conversions, project HQ output etc.

Then I have 2x1.5TB drives (SEAGATE) configured as 2xRAID0 (1.8TB and 0.9TB) for my target space for CANOPUS HQ files. Two RAID's 0 for two reasons: #1 Windows XP, which I use can not handle volumes larger than 2TB, #2 for the reasons mentioned by Brandon above.

Finally my other two 500GB SATA are configured as:
- 500GB RAID 0 for project directory and - mainly - because temp. rendered files are stored by EDIUS in that directory too.
- 250GB RAID 1 for relatively safe, redundant storage for various purposes, e.g. backup of project files, excluding of course large 'rendered' directories.

This configuration works pretty well for me, I have plenty of storage, speed and reliability for not so much money after all. I hope this info helps,

ZB21