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3x750GB Cav.BLK in RAID 5

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Aynjell

Member
Joined
Dec 12, 2008
Anything special I need to do to get 3 750GB caviar blacks to run right in RAID 5? I got them really cheap and I'm determined to get them going in a raid 5. At less than 60$ a piece, I can't really be arsed to send 'em back.

Anybody, any ideas?
 

Automiketic

Member
Joined
Jun 21, 2008
Do you plan to run them via onboard chipset or do you plant to use a RAID card. I'm no pro when it comes to storage but I do know that for RAID 5, a decent RAID card is highly recommended.
 
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Aynjell

Member
Joined
Dec 12, 2008
Do you plan to run them via onboard chipset or do you plant to use a RAID card. I'm no pro when it comes to storage but I do know that for RAID 5, a decent RAID card is highly recommended.

Going to use intel ich10r for now. I might get a raid card someday but it's not in the cards at the moment.
 

mattspalace

I been Dolk'ed Senior
Joined
Jan 14, 2003
Location
Stuttgart, Germany
You should be fine using the onboard raid controller - I think there's a pretty good sticky related to Intel Matrix Raid Arrays - I highly recommend giving that a read.
It's fast though, not SSD fast, but not a whole lot slower - especially for day to day ops. I believe you can run raid 0+5 and get some very good results.
 
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Aynjell

Member
Joined
Dec 12, 2008
You should be fine using the onboard raid controller - I think there's a pretty good sticky related to Intel Matrix Raid Arrays - I highly recommend giving that a read.
It's fast though, not SSD fast, but not a whole lot slower - especially for day to day ops. I believe you can run raid 0+5 and get some very good results.


My 750's are storage only. I have Velociraptor's for main drive.

:comp:
 
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Aynjell

Member
Joined
Dec 12, 2008
ah, yeah you can run raid 5 with the onboard raid controller no problem. That 0+5 setup would smoke your velociraptors though. :D

In benchmarks, some areas would be faster, but it would defeat the purpose. I need at least 1 terabyte of fairly fault tolerant store for backups, and personal stuff. I need about 400-500 for games. the Velociraptor's are just the right size. To stripe 600 out of my raid array would mean a much smaller raid 5, in fact, a pointless raid 5. I need something I can count on. I don't need more speed... and no, 3 750's wouldn't smoke my VR. No way, no how. It'd get close, but the second you started using the other side for anything, which in my situation would happen... it'd die off.

Setup stands as is: 2x300GB VR's in RAID 0, 750x3 in RAID 5, strictly for data storage.

The VR's are the perfect mix of size, access time, and sustained transfer rate.
 
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Aynjell

Member
Joined
Dec 12, 2008
You should be gtg then, although I have never mixed arrays with an onboard controller.

I doubt it'll be a problem. The problems I'm expecting are things that WD might have intentionally put in place to block raid functionality. Does anybody know of such a thing?

Some drives are just allergic to raid, I was concerned this was the case with this drive. I haven't found any reviews showing they are.
 
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moto211

Member
Joined
Jan 4, 2008
Location
Sacramento, CA
Its possible that you might experience issues with drives being dropped from the array as failed even if they haven't failed. The problem is that desktop drives can spend as much as 2-3 minutes doing deep error recovery if they encounter as bad sector, during which time they will not communicate with the controller. If a drive stops talking to a RAID controller for more than 8-15 seconds it will be dropped from the array. This is problem in RAID 5, particularly if it occurs during a rebuild which would cause the array to be lost. You used to be able to enable TLER (time limited error recovery) on the WD Caviar Blacks. TLER limits the drives onboard error recovery to 8 seconds and then passes error recovery responsibilities to the controller. It has been reported that WD no longer allows the user to enable TLER on 1TB Caviar Blacks. I have not heard anything about the 750's. My advice would be to try enabling TLER and see what happens. The DOS utility that is used to enable this feature is WDTLER.exe

If you are unable to enable TLER, my advice is to stay away from RAID 5 as there is too much chance of losing the array. In that case, I would go RAID 10 (RAID 0+1). You would need 1 more drive to do RAID 10. I just set up a RAID 10 and I love it...I get the speed of RAID 0 with the fault tolerance of RAID 1 without the processing overhead of parity calculation (one of the issues with onboard RAID 5).
 
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Aynjell

Member
Joined
Dec 12, 2008
Its possible that you might experience issues with drives being dropped from the array as failed even if they haven't failed. The problem is that desktop drives can spend as much as 2-3 minutes doing deep error recovery if they encounter as bad sector, during which time they will not communicate with the controller. If a drive stops talking to a RAID controller for more than 8-15 seconds it will be dropped from the array. This is problem in RAID 5, particularly if it occurs during a rebuild which would cause the array to be lost. You used to be able to enable TLER (time limited error recovery) on the WD Caviar Blacks. TLER limits the drives onboard error recovery to 8 seconds and then passes error recovery responsibilities to the controller. It has been reported that WD no longer allows the user to enable TLER on 1TB Caviar Blacks. I have not heard anything about the 750's. My advice would be to try enabling TLER and see what happens. The DOS utility that is used to enable this feature is WDTLER.exe

If you are unable to enable TLER, my advice is to stay away from RAID 5 as there is too much chance of losing the array. In that case, I would go RAID 10 (RAID 0+1). You would need 1 more drive to do RAID 10. I just set up a RAID 10 and I love it...I get the speed of RAID 0 with the fault tolerance of RAID 1 without the processing overhead of parity calculation (one of the issues with onboard RAID 5).

This is exactly the kind of information I was looking for. Thank you, Moto211
 
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Aynjell

Member
Joined
Dec 12, 2008
Hurdle 1 for my RAID 5 is handled. For the most recent ones shipping from newegg... the 750GB caviar blacks can be enabled with WDTLER, at least with the version I DL'd. It recognized it as being TLER enabled for 7 seconds on the drive after a reboot. I'll report back on the other two drives, either way, follow the build progress at my build thread, and thanks guys for the help. Moto211, serious props, bro.

http://www.ocforums.com/showthread.php?t=621498
 

moto211

Member
Joined
Jan 4, 2008
Location
Sacramento, CA
No problem man. I almost went with the same configuration as you. The only reason I ended up going with four 1TB Seagates in RAID 10 was because I already had one drive and I was able to get three more retail boxed drives for a good price.

If you have access to a fourth drive, you might want give RAID 10 a test run. There is more wasted space but less rebuild time, better speed, and better fault tolerance. In that configuration you would have the same available space as your current setup, but you would have a better performing array.

If you find that a RAID 10 configuration doesn't suit you, you could always keep the fourth drive and do a four drive RAID 5. If I remember correctly, you get better performance in RAID 5 with more drives. If think more drives reduces rebuild time too since the parity data can be read from more drives.
 
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Aynjell

Member
Joined
Dec 12, 2008
No problem man. I almost went with the same configuration as you. The only reason I ended up going with four 1TB Seagates in RAID 10 was because I already had one drive and I was able to get three more retail boxed drives for a good price.

If you have access to a fourth drive, you might want give RAID 10 a test run. There is more wasted space but less rebuild time, better speed, and better fault tolerance. In that configuration you would have the same available space as your current setup, but you would have a better performing array.

If you find that a RAID 10 configuration doesn't suit you, you could always keep the fourth drive and do a four drive RAID 5. If I remember correctly, you get better performance in RAID 5 with more drives. If think more drives reduces rebuild time too since the parity data can be read from more drives.
Unless I get a stand alone raid card, 3 drives in raid 5 will have to do. I apprecaite the input but, right now I'm limited to sata ports.

One peculiar fact about me is, if the case supports it, or there's a plug I can stick something in, it better work. Onboard sound is ALWAYS setup and working on my boxes, because inspite of the 200$ sound card, I somehow always find a use for it still. Same with esata, and my atcs 840 has an esata port. So that leaves me with 7 of 8 sata ports left. 2 for my RAID 0, leaves me at 5, 3 for my raid 5 leaves me at 2, and then I was hoping to have a blu-ray drive and a CD/DVD burner by plextor. I may opt to simply go with a blu-ray cd/dvd burner combo drive and spring for the extra drive... but who knows.
 
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Aynjell

Member
Joined
Dec 12, 2008
I just picked up a PERC 5/i. I'm going to probably end up getting 2 more 750's and sticking them into RAID 5. This should give me a total of 5 drives, at 3TB, or 2.7 or so after formatting, which should be more than sufficient for my needs, or her needs (my wonderful and loving girlfriend who isn't ripping my head off right now for even thinking about this much hardware).

I am not going to order any of the parts until I know what I got. Per the ebay page, no cables, no bracket, but I got the card, a stick of RAM and the battery for 112$ shipped. Considering another 30$ gets me the cabling and the bracket, I didn't do too terribly... although I missed a better deal here. :(

Anywho, here are the system specs for the rig in question:


  • 3800X2, stock performance, though I may make a point of under-volting it if possible, to bring it's electricity bill down to something reasonable. 2GB of DDR500, probably running at DDR500, but I'll again do my best to undervolt the RAM so I can again bring voltage down, I'd expect ram undervolting might be more power saving than the CPU undervolting, since the RAM already runs at such a high voltage.
  • Motherboard is a DFI SLI-DR, which isn't a good board for a SOHO, but it should be compatible with the Perc 5/i, or so I've read.
  • Of course, 3 right now, but hopefully 5 750GB caviar black drives, and the 6th drive will be a 74GB Raptor (8MB Cache). It'll make an okay OS drive, and that's all it has to be. No reason to retire a 10,000 RPM drive when you can put it in a server, where it belongs. ;)
  • Currently, I got it running on a 510 SLI, but I'm really hoping to find a cheap, quiet, and more efficient power supply. I want to make this box as cost effective for long term 24/7 use as possible... and the less power usage the better... so high efficiency, preferably modular so I can keep the airflow efficient, and I want to get the box low power usage to boot. I have no idea what to expect this thing to pull at the wall, but I'll do my best to minimize that.
  • The case is an Antec 300, thus the current 6 drive maximum. Also, I figured since this box was becoming so many things, and seems to get all my discarded hardware, my nzxt sentry LX will go into it, adding one more function... a CLOCK! :D

This thing is going to be as much an appliance as possible, and less of a computer, if I can pull that off. (does that even make sense)
So yeah, got quite a lot on my plate. :)
 
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