Very New to Raid.....

Discussion in 'General Hardware' started by Heeter, May 2, 2003.

  1. Heeter

    Heeter Overclocked Like A Mother

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    Hi Guys,

    I am wondering about something. As I am reading the searches I have found on RAID, I would like to know if this is for me. I have a lot of files and information, scattered across 3HDD. (Listed Below). As the information and files pile up between all the HDD's, I am left to wonder what should I do about backing up all the HDD"s. I am willing to buy more HDD's (and whatever else) to achieve what Iam trying to achieve, backing up all these Files. Can RAID help me here? Each HDD will be about 85% full by the time I input all my files from other sources. Any Thoughts. I can post a screenshot of my disk manager partitions on the HDD's if the need arises.


    Heeter
     
  2. Indomidable

    Indomidable Guest

    Well RAID is a good place for file protection. The type of RAID you want is RAID mode 1 aka Mirrioring. What it does is stores copies of your HDD in multipule HDD's so if a drive dies you can put in a new one and it will put all the files back, automaticaly. For an IDE RAID solution Hipoint is where it's at next followed by Promise (A well known SCSI-RAID provider)
    RAID 0 or Striping makes all HDD's as one HDD. It's always best to run RAID 0 plus 1 if your going to use RAID 1, because you get the speed bonuses.

    IDE only has RAID 0 and or 1. SCSI has RAID 0-7, with RAID 5 as the most common configuration. Because SCSI can have 7 HDD's per channel(Cable).

    IDE Serial ATA's are up to 150Mb/s Transfer
    IDE ATA 133 = 133 Mb/s Transfer, etc.

    SCSI-Ultra 320 has 320Mb/s Transfer
    SCSI-Ultra 160 Mb/s

    IDE drives are cheap and common.
    SCSI drives are expensive and very fast.
     
  3. Heeter

    Heeter Overclocked Like A Mother

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    But, can I have one big HDD mirroring the other three hdd's in the RAID1 setup? BTW, they are all ATA100IDE. Do I have the protection of backups in the RAID0and1 setup? Is RAID1 realtime type mirroring, I guess I mean if it automatically backedup onto second HDD when file goes into? Or am I understanding this the wrong way. Thanks in advance


    Heeter
     
  4. Indomidable

    Indomidable Guest

    Answers: Ok a RAID runs on Sets so if you had all 3 drives in one set then it would REALTIME keep backups on all 3 drives of all 3 drives reducing splitting the extra info 3 ways. So if you had 2 60 GB drives you'd have with RAID 1 only 60GB's of space. So if one HDD died the other would have all the info and you can Hot-Swap them (If Card Allows). The Rocket-RAID by High-Point and the Promise ATA both allow Hot-Swapping (Replacing of a Drive while PC is on). To make sure you got it RAID 1 is REAL-TIME backup. I reccommend running RAID 0+1 since it's pointless to do it another way. The only problem is there is no convert feature so your info needs to be backed up. So, you can re-install after making the set.
     
  5. Heeter

    Heeter Overclocked Like A Mother

    Messages:
    2,732
    Thanks for the help so far,

    I guess my next question would be this:

    If you were me, You had 80gigs of files spread over 120gigs in three HDD's, using the RAID 0+1 setup, What size of backup dedicated HDD, or set of backup dedicated HDD's would I need to buy? I can even dedicate the 20gig HDD that I have in the system to the RAID backup cause.


    Heeter
     
  6. Indomidable

    Indomidable Guest

    Ok I'd get all the files you had to keep (non-reinstallable Data) Like photos, AVI's, Doc's, etc. put them on the smallest HDD they can fit on.
    Most RAID controllers can have diffrent sized HDD's.
    After doing this I'd get one more big HDD and put the 3 big ones on the RAID controler then once you've got the Set made done at boot with the RAID card flashing something at you like press F1 to enter RAID setup ...
    Install Windows on the RAID move your stuff from the small drive to the RAID 0+1 Set and your done.
     
  7. Indomidable

    Indomidable Guest

    FYI RAID 0+1 or RAID 1 will not fix Windows Regestry errors etc. because it only copies (Real-Time) what is there so if widows screws up it will load screwed up.
    So as hipster doofus gave us a nice link on how to set up your drive to always be working good. Here is that link this will work well on a RAID system too. Link
     
  8. Zedric

    Zedric NTFS Guru Folding Team

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    You asked a question that I'm not sure was answered:
    Maybe it was, but I didn't see it so I'll answer it.

    NO. The HDD:s of a RAID array must be equal in size or it will only use the size of the smallest one. So either you get three more drives (which can be very cramped and bad) or you get one more and set up the RAID 0+1 with all four drives.

    Something else you might want to look into is RAID 5. It requires a more expensive controller card but it wastes less space. RAID 1 wastes half the space (since it's mirror). RAID 5 only wastes one third on three drives, one fourth on four drives and so on. You won't have a normal mirror disk but you can still remove and/or replace a disk without Windows noticing the difference.
     
  9. Un4gIvEn1

    Un4gIvEn1 Moderator

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    There are more RAID configurations than just RAID0 and RAID1 (I am assuming that Indomidable only has experience with IDE RAID). There is also RAID4 and RAID5 (there are other's but these are the most commonly known).

    RAID5 is probably the most useful. With RAID 5 you need atleast 3 drives. For each block of data that is written to one drive, it writes a parity bit on the next drive. As information is written it "stripes" which means that each block is written to the next drive (1,2,3,1,2,3... get it?). If one of the drives fails you need only replace it and the array will rebuild from the parity information stored on the other drives. RAID5 can even be set up with online spares. Online spares are drives that are not used and in the event that one of the drives fails the array will automatically rebuild to an online spare. RAID5 allows you to use as many drives as you would like in an array as well as as many online spares as you would like. It's basically like having a RAID0 with a partiy drive so to speak. The speed of this array is very nice, but very dependant on how much RAM you have.

    RAID4 does drive striping as well, the only difference is that RAID4 does not save the parity information to the next drive in the array, it saves all parity information from all the drives in the array on one drive. I am not even going to talk about the speeds on this one. That's why it isn't used much anymore.

    RAID1 is drive mirroring. RAID 1 also allows for online spares. You can have as many drives in an array for RAID1 as you would like, but each drive will only be as big as the smallest drive. I believe with RAID1 you can use a combination of RAID0 and RAID1. You could say, create 2 arrays of 3 10gig drives using RAID0 and then mirror one array onto the other. Write speeds are worse with RAID1. Read speeds are better.

    RAID0 allows you to create an array that is made up of many drives. There is NO redundancy with RAID0. RAID0 uses striping as well (where it writes the next block of data to the next drive and so on) The drives do not have to be the same size. Read and write speeds improve because of the striping.

    There is also another mode that isn't usually used. It's called linear RAID. This is almost like RAID0, but instead of striping, linear writes to one drive until it's full, and then onto the next.

    I know Indomidable gave you some useful information, but I hope that this helps you a bit more. The RAIDs that he talked of work with IDE RAID. All of the ones above will work with SCSI RAID. RAID4 and RAID5 WILL NOT work with IDE RAID (not yet atleast).

    GOOD LUCK!
     
  10. Zedric

    Zedric NTFS Guru Folding Team

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    Un4gIvEn1: Isn't your RAID 4 called RAID 3?

    I think it's time for my generic RAID post. :) Maybe I should extend it sometime...

    Ok dudes! Here comes "What You Need To Know About RAID". :)

    RAID - Redundant Array of Independant Disks.
    There are several types of RAID. Here are the most important.

    Code:
    RAID 0 - Stripe:
    ======================
    Disk 1		Disk 2
    ------		------
    |  1 |		|  2 |
    |  3 |		|  4 |
    |  5 |		|  6 |
    |  7 |		|  8 |
    |  9 |		| 10 |
    | 11 |		| 12 |
    | 13 |		| 14 |
    | 15 |		| 16 |
    ------		------
    
    RAID 1 - Mirror:
    ======================
    Disk 1		Disk 2
    ------		------
    |  1 |		|  1 |
    |  2 |		|  2 |
    |  3 |		|  3 |
    |  4 |		|  4 |
    |  5 |		|  5 |
    |  6 |		|  6 |
    |  7 |		|  7 |
    |  8 |		|  8 |
    ------		------
    
    RAID 3 (unusual):
    ======================
    P = Parity information
    
    Disk 1	Disk 2	Disk 3
    ------	------	------
    |  1 |	|  2 |	|  P |
    |  3 |	|  4 |	|  P |
    |  5 |	|  6 |	|  P |
    |  7 |	|  8 |	|  P |
    |  9 |	| 10 |	|  P |
    | 11 |	| 12 |	|  P |
    | 13 |	| 14 |	|  P |
    | 15 |	| 16 |	|  P |
    ------	------	------
    
    RAID 5:
    ======================
    P = Parity information
    
    Disk 1	Disk 2	Disk 3
    ------	------	------
    |  P |	|  1 |	|  2 |
    |  3 |	|  P |	|  4 |
    |  5 |	|  6 |	|  P |
    |  P |	|  7 |	|  8 |
    |  9 |	|  P |	| 10 |
    | 11 |	| 12 |	|  P |
    |  P |	| 13 |	| 14 |
    | 15 |	|  P |	| 16 |
    ------	------	------
    RAID 0: Striping. Two disks where the data is spread across the disks so that every second block is on one of the disks.
    + Improves speed.
    - Unsafe.

    RAID 1: Mirroring. Both disks contain the same data.
    + Safe.
    - Wastes half the space.

    RAID 3: A third drive stored parity information (XOR). If one disk dies, the data can be rebuilt using this information. One disk is the parity disk. Can be used for more than 3 disks as well.
    + Safe.
    - Requires complicated controller.

    RAID 5: Every n:th block in an array of n disks is a parity block. If one disk dies data can be saved. Can be used for more than 3 drives.
    + Safe.
    - Requires complicated controller.

    RAID configurations can sometimes be combined if the controller alows it. For example, RAID 50, RAID 10 and so on. RAID 50 requires at least 6 drives.:eek:

    All RAID configurations require the disks to be of the same size. If they are not the size of the array is based on the size of the smallest drive.

    If you don't have drives with the same size and want to run them as JBOD (Just a Bunch Of Disks). A bit like RAID 0 except it's not faster than a single drive.
     
  11. Un4gIvEn1

    Un4gIvEn1 Moderator

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  12. Un4gIvEn1

    Un4gIvEn1 Moderator

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    OK... I got it. RAID3 is at a bite level where RAID4 is at a block level for striping.
     
  13. Heeter

    Heeter Overclocked Like A Mother

    Messages:
    2,732
    Wow, thanks for the other responses!

    So, if I understand correctly, I won't need more HDD's, The three that I have can be setup for RAID5, other than needing the complicated card. Do I have to remove all the files and information of my HDD's before I can setup RAID5? What about partitions, pagefile, printspool, temporary Internet Files? what happens to this stuff with RAID5? Can I still put the pagefile and other stuff onto another HD with theRAID5?Can I keep my partitions as well? Thanks in advance....



    Heeter
     
  14. Un4gIvEn1

    Un4gIvEn1 Moderator

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    Heeter: Yes, you will need to start from scratch with RAID5. About pagefile, the drive will distribute it across the multiple drives. To your OS, you will only have 1 drive, to you computer you will have 3. RAID5 only works with SCSI drives, just remember that. IDE RAID only works in RAID0 and RAID1.

    Good Luck
     
  15. Zedric

    Zedric NTFS Guru Folding Team

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    No that is entirely not true. There are RAID cards for IDE that can do RAID 5. Here's one:

    http://www.adaptec.com/worldwide/pr...ss=no&language=English+US&prodkey=AAR-2400A&

    As you can see it's expencive. :(

    Also you can only use your three old drives if they are the same in size. If they are not it will still work but you will only get 2x the smallest sized drive to play with (third always wasted).
     
  16. Un4gIvEn1

    Un4gIvEn1 Moderator

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    I stand corrected... Thank you Zedric, I was unaware that IDE was able to do RAID5.
     
  17. Heeter

    Heeter Overclocked Like A Mother

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    2,732
    But everything is in IDE in my setup, 390$US is extremely stiff for me right now, But I can afford another IDE HDD and RAID controller card, 1-So what size of HDD would be recommended, judging by what I have already(Please see below, I can get rid of the 20gig if need be).2-Where Can I store approx 45 gigs of info and files that I have already?3-Can RAID 0+1 be used for gaming? Thanks for all the responses so far....


    Heeter
     
  18. Un4gIvEn1

    Un4gIvEn1 Moderator

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    RAID does not affect how a computer fundamentally runs. There are some RAID configurations that are better for different jobs. Something with a faster write time would be recommended for video editing or something similar... If you choose to use the computer size of all your drives then you are basically stuck to RAID0/1 The others require all drives to be the same size so if you have a 20, 40 and 80 you will be stuck to 20 on all 3. Make sense?
     
  19. Zedric

    Zedric NTFS Guru Folding Team

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    The drive configuration you have (20, 40, 60) does pose a problem. They're not suited for RAID since they are different. It would be hard to include them without wasting space (unless you use the 60GB and get more 60GB:s).

    Maybe (just a thought) you could get a 120GB and just use a scheduled program to copy files to that disk during the night or something? It's not RAID but it's cheaper than getting several more disks...
     
  20. Heeter

    Heeter Overclocked Like A Mother

    Messages:
    2,732
    Thanks for all the replies!!!

    After reading all the posts, then going by the setup I already have, I think Zedric makes the most sense for my setup for now, that is get one bigass HDD and buy Norton Ghost or some other program that does scheduled backups. I really appreciate all your guys efforts in helping me out.

    Thanks

    Heeter