Raid 0 Suxxx

[ricochet]

I had two 80 GB. Western D. Hard drives in RAID 0 running for 4 months. I had downloaded about 5 or 6 DVDRs to burn to disk this weekend. :D My new 50 pack of DVDR disks were due Friday from ups. :lol: On Friday afternoon my wife ( when i was at work) went to get on.
She said she got a error that a file could not be found ( for startup) and that it needed the windows disk to repair it. She tried to repair it and the repair failed. :(

When I got home, thinking I was going to watch a new recorded DVD, Then go to the Bar. She told me about this. After some looking into it I found that 1 of my hard drives failed. :( I could not even reformat the drives. I have now bought a 60 GB. Maxtor (master) and a 160 GB. Maxtor (slave) drive.

No more RAID 0 for me... :angry: Running this way I see no difference in speed...

I understand that in RAID 0 the data gets wrote to both disks at the same time.

Is there any way to recover data from a reformatted disk that ran in RAID 0 ???

Would that data be usable ??? or complete ???

[lynx]

Raid 0 is striping. Data blocks are written alternately to one disk then the other, so neither disk has a complete set of data. It is supposedly the fastest raid implementation, but on an IDE system with both drives sharing the same bus it is unlikely to be much faster than treating it as 2 separate drives, with the downside that if you lose one drive you lose the contents of both.

So I'm afraid the answer is no, it has all gone.

[SingaBoiy]

Whats the difference between Raid 0 and Raid 1?

[clocker]

Raid0, as lynx said, stripes the data across two drives.
Windows sees the drives as one big drive.
If one drive fails it takes out the whole shebang.

RAID 1 mirrors data...the second drive is a copy of the first, so if one drive fails the system carries on using the second drive...no data has been lost.

[Virtualbody1234]

Yup. I have to agree with ricochet. Quite a while ago I had a setup with raid 0 using onboard Highpoint RAID controller. The motherboard failed (don't know why). After that I found out that I couldn't access my data anymore eventhough the drives were perfectly fine. The only way would have been for me to puchase the same motherboard again. There was no way I was going to do that. It failed so I didn't want the same product again (Abit). Also the newer boards were available with more advanced features for less money. So the data went bye bye.

[SingaBoiy]

You coulda bought it, transfered the data, then took it back.

[clocker]

Oddly enough, the machine I'm using to post is my first experience withe RAID0.

Yesterday I completed the initial build of my brother's second server.
As he is out of the country for a few weeks I was free to install XP on it and play around for a while.
Like the first machine, this too has twin 74GB Raptors and I was interested to see how the striped array "felt" during my normal usage.

So far, not terribly different than my WD IDE drive.
Boot time is fast, but I don't have a lot of programs loaded, so the comparison is invalid.
At any rate, it's certainly not the blazingly fast revelation that some would have you believe.

My next move is to wipe the array and build a mirrored set ( RAID1).
Mostly, I'm interested in how Windows will "see" the disks in Disk Management.

His old server ( Server 2000 with SCSI disks) showed TWO C:drives and monitored their health.
My first server ( Server 2003 with SATA disks) showed but ONE drive.
Microsoft says that currently Server 2003 does not deal with SATA well and perhaps a patch will be made available.
We are interested in seeing if XP will display both drives under RAID 1.

From a business's standpoint it is NOT acceptable to be unable to verify that BOTH disks in the array are in good shape.
We have no doubt that the mirroring is taking place, but the inability to tell if one of the drives has failed severely comprimises the whole security issue that RAID 1 is supposed to afford.

This blind spot for SATA drives seems an odd oversight on MS's part...surely many small businesses are using SATA as a replacement for the more expensive SCSI alternative and increasing number of consumer grade motherboards have SATA RAID incorporated on-board.

[Virtualbody1234]

Originally posted by SingaBoiy@8 August 2004 - 11:37
You coulda bought it, transfered the data, then took it back.
That's not my style.

[SingaBoiy]

Originally posted by Virtualbody1234+8 August 2004 - 13:39--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Virtualbody1234 @ 8 August 2004 - 13:39)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-SingaBoiy@8 August 2004 - 11:37
You coulda bought it, transfered the data, then took it back.
That&#39;s not my style. [/b][/quote]
:lol:

:P

[lynx]

@Clocker, If Disk Management sees 2 C: drives then the raid is implemented with software, not hardware. With a hardware raid controller the physical number of drives is masked to the outside world, it is usual that only one drive is visible, although this can vary depending on configuration.

To give an example, you may have 4 drives in a raid configuration. These can be configured as a single drive array (visible only to the raid controller), and that array can then be split into a number of visible drives as seen by the rest of the system, in a similar way that a single drive can be partitioned. Obviously, if this is done at a software level rather than hardware then the OS must see all the physical drives, which is what you described.

Even with hardware raid, there are ways to see the status of individual drives, but this is subject to the hardware manufacturer supplying software for this purpose. As with all hardware specific drivers it is not Microsoft&#39;s responsibility to provide these solutions, although they often do when the hardware is sufficiently popular. That is not likely to be the case for SATA raid solutions, at least in the short term.

[Virtualbody1234]

Nice new avatar, lynx. B)

[tesco]

Originally posted by Virtualbody1234+8 August 2004 - 17:39--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Virtualbody1234 @ 8 August 2004 - 17:39)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-SingaBoiy@8 August 2004 - 11:37
You coulda bought it, transfered the data, then took it back.
That&#39;s not my style. [/b][/quote]
my dad would have done it. :lol:
he&#39;s the master at, umm, "buying-then-returning" :blink: :unsure:



hey i was in quebec 2 days ago. :D How far is montreal from hull? :lol:

[clocker]

Thanks, lynx.

So there is no way to monitor the status of both drives, eh?
Bummer.

[Virtualbody1234]

Originally posted by ROSSCO_2004+8 August 2004 - 21:17--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (ROSSCO_2004 @ 8 August 2004 - 21:17)</td></tr><tr><td id='QUOTE'>
Originally posted by Virtualbody1234@8 August 2004 - 17:39
<!--QuoteBegin-SingaBoiy@8 August 2004 - 11:37
You coulda bought it, transfered the data, then took it back.
That&#39;s not my style.
my dad would have done it. :lol:
he&#39;s the master at, umm, "buying-then-returning" :blink: :unsure:



hey i was in quebec 2 days ago. :D How far is montreal from hull? :lol: [/b][/quote]
About an hour and a half drive.

[3RA1N1AC]

that&#39;s why you need to buy 4 hard drives, so you can make a RAID 0+1 setup. first two drives = stripe RAID, second two drives = backup of the stripe RAID. :lol:

i woulda never recommended using a stripe RAID for a PC. if you&#39;re running a dedicated server or a professional workstation, with absolutely no important personal files on it... then go ahead and knock yerself out. but for a PC? nah, not a good idea.

[ricochet]

I guess you could call it,* live and learn*

[lynx]

Originally posted by clocker@9 August 2004 - 04:25
Thanks, lynx.

So there is no way to monitor the status of both drives, eh?
Bummer.
Have you looked at "Silicon Image ATA Controllers" in Control Panel?

That seems to go down to hardware level with one drive, I&#39;m not sure what info it gives in a raid situation but it is worth a look. I actually posted all this before but you must have missed it. I was surprised that you hadn&#39;t responded then.

I also found this (http://12.24.47.40/display/2n/kb/article.asp?aid=10469):

SiI3x12A: Serial ATA (SATA) Windows RAID Driver - Released

NEW – Version 10032 of the SiI3x12 Windows RAID driver is now logo-certified for Windows 2003 Server.

The latest Windows RAID driver for the SiI3x12A SATA Controller chip (3x12A_x86_win_rdrv-xxxxx.zip) can be downloaded from the links on the right.&nbsp; These drivers support Windows 98SE/ME/NT/2000/XP.&nbsp; Windows 95 is not supported.

Please NOTE that these are the latest GENERAL drivers that are available from Silicon Image. Some motherboard or add-in card makers may post versions with later revision numbers than the one shown here, but those are written specifically for their designs and are not intended for general use.

The latest version of Silicon Image SATARAID RAID Manager software is also attached on the right.


Comments/Special Instructions:
Preparing a &#39;Silicon Image SiI 3x12 Raid Driver Installation Disk&#39;

Follow these instructions if you are creating a diskette containing the Silicon Image SiI 3x12 Raid driver.

1. Format a blank floppy diskette.

2. Use WinZip or a similar utility to unzip the Driver Zip file (3x12A_x86_win_rdrv-xxxxx.zip).Make sure you use the rdrv file and NOT the SATARAID file. The SATARAID file is the Windows RAID Manager GUI. It is not the RAID driver and will be too large to fit on a floppy. If it does not fit on a floppy, you are using the wrong file.

.
.
.
.

Note the last bit, Windows RAID Manager GUI, this must be what you are looking for.

Edit: tried it, I think the Java_RAID_GUI-113.zip is the file you need.

@3RA1N1AC - have you ever tried a raid 5 setup? That gives striping with distributed parity with only 3 drives - one drive can fail and the system still works. Cheaper than Raid 0+1, and often faster depending on implementation.

[tesco]

Originally posted by Virtualbody1234+9 August 2004 - 00:28--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Virtualbody1234 @ 9 August 2004 - 00:28)</td></tr><tr><td id='QUOTE'>
Originally posted by ROSSCO_2004@8 August 2004 - 21:17

Originally posted by Virtualbody1234@8 August 2004 - 17:39
<!--QuoteBegin-SingaBoiy@8 August 2004 - 11:37
You coulda bought it, transfered the data, then took it back.
That&#39;s not my style.
my dad would have done it. :lol:
he&#39;s the master at, umm, "buying-then-returning" :blink: :unsure:



hey i was in quebec 2 days ago. :D How far is montreal from hull? :lol:
About an hour and a half drive. [/b][/quote]
hmm, compared to all the driving i&#39;ve been doing the past 2 weeks, that&#39;s nothing. shoulda gone.

oh well maybe next year or something. :)

[3RA1N1AC]

Originally posted by lynx@9 August 2004 - 05:50
@3RA1N1AC - have you ever tried a raid 5 setup? That gives striping with distributed parity with only 3 drives - one drive can fail and the system still works. Cheaper than Raid 0+1, and often faster depending on implementation.
haven&#39;t tried it, but yeh i have read some explanations whilst poking around.

i was just commenting on the basic uselessness of striping for home/office use. people seem so dazzled by the "wow, cool" aspect and potentially misleading bench test results on gung-ho "performance at all costs" hobby sites that they ignore the part about RAID 0 increasing one&#39;s risk of complete data loss.

[muchspl2]

herd good things about raid 5
my next system will be it
form what I understand if one drive fails you can fix it & even if 2 drives fail you can fix it

[lynx]

Originally posted by muchspl2@11 August 2004 - 05:24
herd good things about raid 5
my next system will be it
form what I understand if one drive fails you can fix it & even if 2 drives fail you can fix it
Nope, only one drive. Assuming you have 3 drives, it works on the principle A(xor)B=C, where A and B are actual data on two of the drives and C is the checksum. So if one drive fails you either have A and B, A and C (B=C(xor)A) or B and C (A=C(xor)B ).The data on the three drives is laid out as follows:
ABC
CAB
BCA
ABC
etc, so that when a drive fails it only has to do the calculation to recover the lost data once in every three reads on average. Obviously there is a slight performance hit, but not too bad.

With some systems you can even replace the drive without shutting the system down (hot swapping), but even if that&#39;s not possible you only have to be down for the few minutes it takes to physically replace the drive, and can then build the raid structure while the system is running.

[muchspl2]

I was under the impression with 5 drives (in raid 5) you could replace up to 2 if need be...

[lynx]

Originally posted by muchspl2@11 August 2004 - 17:18
I was under the impression with 5 drives (in raid 5) you could replace up to 2 if need be...
That&#39;s raid 6.

Expensive to implement (you lose 2 drives), needs a very complex controller, and write performance is very poor.

Very high availability though, with 6 or more drives you can have up to 3 failed drives if the controller has been set up correctly (I believe with enough drives you could even have 4 simultaneous failures).

Chances of 2 simultaneous failures are so small that no-one has built a commercial raid 6 controller.

Therre are raid types where 2 non-adjacent drives can fail without compromising the system, usually raid 10 (with 4 drives) and raid 1E (with 5 drives), but they aren&#39;t commonly used.

[muchspl2]

OK then its raid 6
cause I knew you could replace 2 or 3 if need be, but you need a MB that supports it, I&#39;m guessing most don&#39;t