Any Raid Experts?

[trekiej]

Thanks.
An Article I was reading said that the user should have Backup Storage in case of a raid failure.
It also said ( or another post ) that cost wise that Raid 1+0 was better than Raid5 on the second disk failure.
For a newbie, it looks like the Holy Grail, when it fails it becomes a Holy Cow.
The board I want to get has 6Gbs SATA. How can I push that to the limit?  
Do I need SSD's or many HD's?
Can a raid system beat the bloat?

[pyrre]

The best bang for the buck for multiple drives is to get a HighPoint eSATA RAID card. The 622 is a two eSATA port card that can use up to 10 drives, and the 644 or 2314 has four ports and can use up to 20. eSATA port multiplier enclosures are not horribly expensive. A Sans Digital five bay enclosure, for instance, is around $200 USD from NewEgg.

This description sounds like JBOD (just a bunch of disks) and is NOT in any way a raid. It is an array, yes. and will set any disk of any size into an array of ONE logic drive. However. if one disk fails... ALL data is lost...
i have tried it!!!
(linux and LVM may rescue your back...)
(unless you mount the drives as separate drives...)

RAID-0 (sic) shouldn't even be discussed. It's not RAID since R in RAID stands for redundant, and striping drives makes things less safe than keeping them on a single drive. (Is there such a thing as negative redundancy?)

Raid 0, or striping is performance wise the fastest setup.
It is good for, lets say. striping two disks as SYSTEM disks.
IF you are cautious about your placement of files you have no real loss if one drive fails.
Or you could set up multiple drives in raid 0, as a master drive for video editing. Recording the master to that drive before packing it and burning it to BD disks or moving it to your raid 5 for storage.
Raid 0 suits the needs of a fast drive to handle drive intensive operations.
And always remember to back up files.

The simplest RAID setup is simple mirroring. Most x86 motherboards support BIOS-based mirroring. I'm not sure whether Windows has software mirroring, but just about any Unix-like OS (BSD, OS X, GNU/Linux) has software-based mirroring. You can also buy hardware-based mirroring enclosures which appear as one drive to OSes which don't have support (such as AmigaDOS).

Yes and no... Striping two disks is as well easy. (unless safety if your goal) And gives a great speed increase.
However, i would stay clear of ANY motherboard raid controllers.
If you move to a new motherboard or it in worst case scenario fails...
You have no guaranties you will be able to restore your raid.
ALWAYS use separate controllers. They will also give a speed benefit since they remove disk operations from the CPU!
IMHO stay the hell clear of any software based raids. if you loose the raid table (which is very easy if your OS fails or crashes during write ops..) you loose the entire raid and all data stored.
I have tried it to

If you're worried about viruses, then that implies you're using Windows. There's nothing RAID can do that can save you from that. Your only option then is to maintain two copies of everything, which is what others have said above.

What about a anti virus software?

[pyrre]

Thanks.
An Article I was reading said that the user should have Backup Storage in case of a raid failure.
It also said ( or another post ) that cost wise that Raid 1+0 was better than Raid5 on the second disk failure.
For a newbie, it looks like the Holy Grail, when it fails it becomes a Holy Cow.
The board I want to get has 6Gbs SATA. How can I push that to the limit?  
Do I need SSD's or many HD's?
Can a raid system beat the bloat?

I am not going to argue. but i would never use motherboard controllers for raid. especially if speed is an issue.
Dedicated controllers will remove a great deal of disk operation from the cpu.
And you have fall back, in case motherboard fails.

I have never had speed problems like piru og alexh explains when multiple computers access my server.
network has been the bottleneck then, even gigabit...
(for a HOME network!)

I would any day choose RAID 5 or 6 and a dedicated controller. My humble opinion though...

[trekiej]

How about the Raid 1+0 or I hear it is also called Raid10.
|| = mirror
+ = stripe

[ a || a' ] + [ b || b' ] + [ c || c' ]
I do not think you have to replace the whole set if you loose one.
1.  I want to make win7 or win sever run faster.
2.  I want to make Linux run faster? (ubuntu, fedora, slackware )
3.  I want to edit movies with Blender.
4.  I want to edit moves with Sony Vegas Pro 9.
I plan to add a 1TB drive for back up.
Thanks.
Extra:

SATA
5 SATA 6 Gb/s ports by AMD® SB850
1 E-SATA port by AMD® SB850

RAID
SATA 1~5 support RAID 0/ 1/ 10/ 5 mode by AMD® SB850

[Sparky]

I am planning to build a new computer and I wanted to get some advice on Raid5 and Raid 1+0.

I don't think anyone has asked this question of you yet ... but what are you wanting to use the storage for ?

Operating System ?
Personal documents and photos that are irreplaceable you can never afford to lose ?
Music/video/pron collection ?
Corporate filesystem ?
Database ?
Scratch disk for video editing work ?

Depending on what you want depends on the configuration of the underlying disk.

[pyrre]

How about the Raid 1+0 or I hear it is also called Raid10.
|| = mirror
+ = stripe

[ a || a' ] + [ b || b' ] + [ c || c' ]
I do not think you have to replace the whole set if you loose one.
1.  I want to make win7 or win sever run faster.
2.  I want to make Linux run faster? (ubuntu, fedora, slackware )
3.  I want to edit movies with Blender.
4.  I want to edit moves with Sony Vegas Pro 9.
I plan to add a 1TB drive for back up.
Thanks.
Extra:

SATA
5 SATA 6 Gb/s ports by AMD® SB850
1 E-SATA port by AMD® SB850

RAID
SATA 1~5 support RAID 0/ 1/ 10/ 5 mode by AMD® SB850

RAID 1+0 10 or what ever.
[ a1 || a2 ] + [ b1 || b2 ] + [ c1 || c2 ] - Disks A1 and A2 are striped together as goes for B1/2 and C1/2.. array A is "master" and array B and C mirrors A. Adding more mirrors will NOT increase capacity.
(you can of course expand with A3, B3 and C3. increasing overall capacity. but consuming tree more disks.)

That setup consumes 6 disks, and will survive a up to two disk failure.
OTOH
RAID 6 requires a minimum of four disk and will use two disks for parity.
Hower it will survide up to two disk failure. And by merging more disks you will increase overall storage. And maintaining two disk failure.
Like i have said before. i see no real reason to use mirroring!

To run OS faster, stripe two SSD disks together on motherboard controller. And use ONLY system on that controller. My friend has reached read speeds of over 400MB/sec doing so!

As for speeds... on a private home network you will rarely use the max drive speeds.
I have raided 6 120gig PATA disks, alone they are slow as hell.. but in a raid they are lightning fast. And i never saw anything to evidence speed penalties.

If you want os to run faster.. buy yourself a hyperdrive V5!
Or even raid multiple hyperdrive 5...
http://www.hyperossystems.co.uk/
(but now we are getting seriously expensive!!!)
Or upgrade RAM or/and CPU....

Move editing: while working on files: RAID 0. For storing files: RAID 5 or 6... MHO
I use vegas video 4 (predecessor to sony vegas 9) whit a similar setup.. Disk speed was never an issue.. CPU AND RAM is!
Get a dual Xeon HT quad core 64gig ram and Nvidia Quadro... That will render movies a bit faster.

Backup is NEVER underestimated...

[sknight]

I found another nice step by step guide for you on how to setup a Home Fileserver using ZFS: http://breden.org.uk/2008/03/02/a-home-fileserver-using-zfs/

Take a special look at the chapters 2 and 3 where the author compares the existing products and explains why ZFS is the best solution nowadays.

If you want to be serious forget RAID (mainly on Windows)...

[kolla]

Another thing to look at for the ZFS fetishists... http://www.nexentastor.org/

[X-ray]

I have a Silicon Image 3112 card, with two SATA 200gb drives in RAID 1.
One of the disks died and I was able to get my data off the other disk. When I replaced the mobo, I carried on using the card and drive, no problems.

[AJCopland]

This isn't exactly on topic but I use an SSD for my boot/OS/programs drive and a RAID1 array for my precious data/Steam/Games/Videos/Music/etc.

It works pretty well, although I'm using the Intel fake-raid.

The SSD was the best upgrade I've ever bought though, screw the RAID array, get an external HDD to backup to and grab yourself a _good_ SSD for your boot drive.

Hell if you can afford it go for one of these:
http://www.anandtech.com/show/3788/oczs-revodrive-pcie-ssd-preview-an-affordable-pcie-ssd



Andy

[pyrre]

This isn't exactly on topic but I use an SSD for my boot/OS/programs drive and a RAID1 array for my precious data/Steam/Games/Videos/Music/etc.

It works pretty well, although I'm using the Intel fake-raid.

The SSD was the best upgrade I've ever bought though, screw the RAID array, get an external HDD to backup to and grab yourself a _good_ SSD for your boot drive.

Hell if you can afford it go for one of these:
http://www.anandtech.com/show/3788/oczs-revodrive-pcie-ssd-preview-an-affordable-pcie-ssd



Andy

SSD drives are dying even faster than conventional HDDs...
no safety in using SSD drives. SSD gives grater speeds...
Only secure backup media i know are tapes or CD/DVD/BD....
(even they have a limited lifetime)

[kolla]

Double post \o/

[kolla]

What's so safe with tapes?
I have had more trouble with tape than with all other media combined.

[tone007]

What's so safe with tapes?
I have had more trouble with tape than with all other media combined.

Redunancy, for the most part.  If you've got a different tape for every day of the week, if one decides to give you problems, go back one more day.

Not that I've had any reliability issues with SuperDLT tapes... probably should look into a new set though, these are getting old..

[johnklos]

This description sounds like JBOD (just a bunch of disks) and is NOT in any way a raid. It is an array, yes. and will set any disk of any size into an array of ONE logic drive. However. if one disk fails... ALL data is lost...
i have tried it!!!
(linux and LVM may rescue your back...)
(unless you mount the drives as separate drives...)

No, the cards I posted all do hardware-based RAID-5. (I did mention that they're RAID cards.)

Raid 0, or striping is performance wise the fastest setup.
It is good for, lets say. striping two disks as SYSTEM disks.
IF you are cautious about your placement of files you have no real loss if one drive fails.

There are no benefits of AID-0 (not RAID) which can survive data loss. The only way it's even possible to recover data from an AID-0 setup is if you set up two disks as a concatenated set and the filesystem supports growing, but doesn't yet grow to the second drive, meaning it's worthless to even consider such a setup. Failure of any drive in AID-0, for all practical purposes, means loss of all data.

Or you could set up multiple drives in raid 0, as a master drive for video editing. Recording the master to that drive before packing it and burning it to BD disks or moving it to your raid 5 for storage.
Raid 0 suits the needs of a fast drive to handle drive intensive operations.
And always remember to back up files.

AID-0 is no faster at lots of small I/O than RAID-1 or RAID-5 since you're still waiting for the mechanical movement of heads and you're still waiting for the average rotational latency period. AID-0 is faster for streaming contiguous files faster, though.

Without redundancy, though, it's pretty much worthless these days since even the inexpensive HighPoint cards I mentioned can do uncompressed full 1080 resolution high definition video with RAID-5.

[Piru]

I just had my first HDD failure with the RAID-5. One of the 1.5TB Barraducas (ST31500541AS) dropped dead. I've swapped the drive and added the new HDD to the array with:

Code: [Select]

sudo mdadm /dev/md0 --add /dev/sdh1The raid is now rebuilding itself:

Code: [Select]

Personalities : [raid6] [raid5] [raid4]
md0 : active raid5 sdh1[3] sdb1[0] sdg1[2]
      2930276864 blocks level 5, 128k chunk, algorithm 2 [3/2] [U_U]
      [=>...................]  recovery =  8.0% (117313844/1465138432) finish=516.8min speed=43460K/sec
     
unused devices:
This is the critical part. If the rebuilding fails due to failure in the remaining good drives I will lose the array and all data within. If it was RAID-6 I could still lose a 2nd disk without data loss.

Obviously I've backed up all important data before the rebuild, so only some less important data would be lost if 2nd disk failure should occur.