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saminco

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Adding RAID 1 <or other options??> to current systems

Currently my Servers are on IDE HD's.  I would like to RAID 1 them.  Now on some of my servers I have 2 or 3 HD's...might this cause any issues/configiration problems?  As I would like to have ALL Server related HD's setup for RAID 1.  In order to do RAID 1, do all the HD's need to be the same model#'s?


Example<s> of current configuration:

Server 1
IDE 30gig c:
IDE 70gig e:

Server 2
IDE 20gig c:
IDE 60gig e:

Server 3
IDE 10gig c:
IDE 74gig e:

Might it be possible/logical to RAID1 ALL of the above HD's?  Also, is there possibly a solution to RAID them to another server case with more space and slide out HOT swap?

Thank You KINDLY

P.S I do infact have more Servers, but there are the most critical ones at this time.
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nobus
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they do not need to be the same model n#, but i would suggest taking only comparable ones, regarding to capacity and speed, so in yous case, that should be the 70, 60, and 74 Gb drive. You could connect the other drives to an IDE port if available.
If Possible, however, buying new drives of 120-300Gb of the same model for the RAID setup would probable be better in the end
Considering RAID level 1 I'm affraid you have to use identical hard drives ...
take a look at this:

http://www.pcguide.com/ref/hdd/perf/raid/levels/singleLevel1-c.html

and UI think this is a pretty good tutorial for RAID-ing ...

http://www.acnc.com/04_01_01.html

I hope this helps you out ...

Considering of RADING to another server ...umm not quite sure about thatone ... cause you need a very quick connection from one server to another ... suppose it is possible ... but not practical.
nobus I'm affraid that the drives have to be identical because of the real time mirroing in RAID 1 - equal speed, and if the drives are not identical differ in a few MB's ... that can bring quite a horror in the system.

Here's what they say about it in the article you posted :

Hard Disk Requirements: Exactly two hard disks. Any type may be used but they should ideally be identical

They can be different, but the smallest size of course can only be used
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saminco

ASKER

Yeah, I thought they had to be identical.  So then, as I might not be able to locate exact model to RAID1, what might be the next possible logical step?  I'm not concerned about really backup purposes <currently I backup to internal/external HD(s), Tape, and DVD>.  I am more looking for in case a HD fails, to be able to "swap" to a mirrored one.  Example: DC, Terminal Server, Mail Server <----FreeBSD.

Thank You <all>
I think this link will give you all the answers you need

http://www.acnc.com/04_01_01.html

Did you look through all the RAID levels ?

It's pretty clear ... and easy to pick from there what you need ...
I'd go for RAID1 definately .. if the identical drives are a problem ... in that case .. take a look at some higher RAID levels.. striping .. or Humming code ...
RAID concept except 0 Level is actually built for that purpose .. if a HD fails that server continues to function normally ..
I hope this helps out ...

They DO NOT need to be identical, they say : ideally they should be identical, as the smallest one will limit the size of the mirror, and the slowest will bring the speed down.
If they are identical, they run all at the same speed, on the same sized volume
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Well after further review, it looks like RAID 1 will be my route.  I will just have to hunt down my model numbers.  Now as far as implamenting RAID1...</insert link>.  Just attach and configure via Disk Management?  Or would a seperate software solution be a "better route/means?  Keep in mind IDE;  not S-ATA or SCSI drives.

Thank You < Physicistm>
Well .. I think that the best thing would be the Disk Managment thisway you're avoiding the software malfunction and possible  virus influence. Well on the other hand  depends on how the controller handles the drives.

You're welcome.
You can also use a pci raid controller, if your motherboard does not have one

http://www.addonics.com/products/host_controller/sata_controller.asp

http://www.promise.com/
I disagree - I don't feel they need to be identical.  they SHOULD  have the same RPM and buffer, but I don't believe they have to be identical.  Here's why:

1.  I have a software RAID 1 using a 10GB drive and a 160 GB drive.  The 10 GB drive is my C drive and mirrored onto 10GB of space on the 160.  Never had a problem (and they don't even have the same RPM/buffer specs).
2.  When Dell sent replacement disks for systems I had RAID on, they NEVER inquired about the RAID level, they just sent replacement disks with the same speed and buffer ratings.  Most of the time, they were different brands.  (I will say in most cases, they were setup in RAID 5 configs and SCSI).
3.  Check the RAID documentation.  It's certainly not going to hurt if you use identical disks and may be better if you do - but in my experience, you don't have to.
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So in short in reference to the "same models":

Example:

30gig

Configuration RAID 1 to

40gig

10gig's would be lost

So it would take the "smallest/slowest" and disregard the additional speed/space?  If that is the case, then I can just get as close <gig/speed wise> and config.  

Sound correct?

BTW Thanks Nobus too ;)
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ASKER

Leew,

So do you loose the other 150gig's?  Or does that dirve have multi-partitions?
Well Raid Level 5 is quite a different Storry that you have to keep in mind ... - these are independent data disks with parity block distribution in which case you can use drives whichever you choose, but. since you're impelemnting a RAID to avoid disk
failures the best would be to use RAID 1 which is actually the system that ensures you minimal impact on Hard drive failure ..
"Under certain circumstances, RAID 1 can sustain multiple simultaneous drive failures" ... as the presentation well says there.
In my experience I have always been using identical drives in RAID systems and no problems so far ... even upon failures.
leew, are you sure about this? i gree it would be best, but is it necessary? :

 they SHOULD  have the same RPM and buffer

it's hard to believe that your 10Gb drive has the same specs as the 160 Gb one
The other 150 is available as a non-RAID partition. - Keep in mind I said SOFTWARE RAID.  Hardware, in my opinion is better.  BUT, in every RAID controller I've seen, it's BIOS cuts up the disks to use what it needs for the RAID type chosen and leaves the rest as just an empty space that can be seen by the OS (just wouldn't be RAID).
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Physicistm understood.

Now if I dont have any more "IDE" connections available, a PCI RAID controller would be the solution? <http://images10.newegg.com/productimage/15-104-214-01.JPG

Thank You ALL, my "line of fire" questions are almost all answered.  
It all depends on the RAID controller implementation I think ... if the drives are not identical then the controller has to have quite a big buffer to handle the data and write them on a hard drive in a proper way ... which is expensive ...
but that goes slightly off the topic here ...
Yep ... there are various PCI controllers available ...

Hope we were able to help you ...
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ASKER

I think I am going to go pickup one of these today and test it out:  http://www.techdepot.com/product.asp?productid=1060119&iid=1252&Hits=75&HKeyword=pci+raid  

Physicistm,

Yes, VERY helpful.  

 
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ASKER

well, it just so happens that my local CompUSA had the exact model HD as on my "testing desktop" machine along with an Adaptec ATA RAID controller :) .  Time to test setup and then head for the Servers.

Thanks Guys/Gals for all your information.
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Physicistm
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Setup Question:


I have the following:

Adaptec ATA RAID 1200A controller configured as RAID 1
1 Seagate 40gig HD <Primary Master>
1 Seagate 40gig HD <Secondary Master>

Created the Array and duplicated to secondary master.

Booted to desktop, opened Adaptec Software, both ddrives show up fine.

Shutdown, disconnected  Primary Master <IDE/Power>
Booted up, was prompted to "break the mirror" or continue to boot.

Should it have booted off the mirrored image as "normal" without any user intervention?  Might there be a way to configure that way if not?  

I connected the mirrored HD directly to the MB and booted just fine.

Thoughts?


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ASKER

In addition:  While setup in RAID1 configuration, it seems to take a bit longer to get to XP Sign-on screen <20 seconds -vs- 1minute> is this "normal" ?

Well wasn't paying much attention to thaton .. but now that you mention it .. I think it is ...
Because of the disk syncronization I suppose ... but in general in RAID 0 you should experience faster disc access in RAID 1 not really beacuse of the mirroring ...
No thoughts ... sounds everything fine to me ...
Way to go ! and congrats on your first RAID system :))
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ASKER

RAID1 " May not support hot swap of failed disk when implemented in "software"" I'm using a RAID controller ??

Well, boot time is not an issue as once setup is confirmed working, this setup will be on Servers...but isn't RAID1 fault tolerant?  To where if primary master dies, secondary master will take on "booting" rights/tasks?



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ASKER

Physicistm <side note, is there a way to accept a reply with leaving this thread open>
umm well ...
hmm once you accpet answer you still can post notes to this thread but for other people it will appear as Answered, which won't prevent them from posting messages to this thread, I'm still kind of a new to this thing too ..

haven't figuered everything out yet ...

but you can open a new thread and refer to the previous one ...when asking a question ...
Well .. Thank you !
Glad we could make it work for you!
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ASKER

Well, it is in fact fault tolerant.  As I unplugged the pri. master HD and the mirred HD continued to work.  Then I reattached the power on the pri. master and it began to rebuild :) .

Now to get moving on my Servers.  MUCH THANKS Physicistm <and others>.


/closed

nice !