RAID question

Message

KePSuX · Post by **KePSuX** » Tue Jan 20, 2004 6:32 am

I'm about to build a new file/http server to replace my old and busted redhat machine. I will be putting 2x250 gig ATA (not serial) Hard Drives in the system for mirroring (fault tolerant) purposes. The OS (Gentoo Kernel 2.6.x) will reside on these discs along with the data. I have seen disputes all over these forms about hardware ATA-RAID controllers not actually working right under 2.6.x and many different gripes about them working in general. What should be my plan of attack? What kind of card should I get, and would it be better for me to look into getting a normal ATA controller with a software RAID solution? I just want my data safe! haha. Anwyays...where should I start?

By the way...disc access speed isn't a huge issue - but costs are. If I needed to buy a RAID card I was hoping to pick one up for under $100 U.S. Thanks guys!

reconciledthief · Post by **reconciledthief** » Tue Jan 20, 2004 6:35 am

Dunno about the IDE raid controller you would need but when you do the install, but when I did my install (scsi's) instead of installing the OS onto the scsi drives, I put in a 8GB Seagate IDE drive and made it a system drive, so the scsi's host only data.

I'm sure there are better ways to do raid, but that's what I did. It could be something to think about

KePSuX · Post by **KePSuX** » Tue Jan 20, 2004 1:22 pm

Yea, that may be what i do...but if i have the drive the OS resides on fail I can't have the server down for 3 days while I reinstall Gentoo and get all the packages/config files updated.

kormoc · Post by **kormoc** » Tue Jan 20, 2004 2:40 pm

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Crg · Post by **Crg** » Tue Jan 20, 2004 4:47 pm

KePSuX wrote: Drives in the system for mirroring (fault tolerant) purposes. The OS (Gentoo Kernel 2.6.x) will reside on these discs along with the data. I have seen disputes all over these forms about hardware ATA-RAID controllers not actually working right under 2.6.x

1) Hardware IDE RAID controllers do work on linux, for example 3ware.
2) Most IDE cards labeled as "RAID" aren't hardware raid, but are IDE controllers with software raid implemented in the driver.
3) The "ATARAID" driver that was in 2.4 is not a solution if you want to use redundancy and to make your data safe as I have mentioned and explained on many post of this forum.

KePSuX · Post by **KePSuX** » Tue Jan 20, 2004 7:11 pm

Fantastic information from everyone as usual! Thanks a lot. I think I'll be able to swing the extra cost for the 3ware card. Now i just have to save up for the drives. heh. Thanks again for the clarrification on the subject.

reconciledthief · Post by **reconciledthief** » Tue Jan 20, 2004 8:50 pm

I'm using software raid and, true, hardware raid is always preferrable, but on my dual p2 350 system it rarely ever uses more than a few percent of either CPU, even when copying large files or server alot of data to users through SMB.

TheCoop · Post by **TheCoop** » Tue Jan 20, 2004 8:53 pm

software raid is a lot better and more configurable than cheapo raid controllers, but if you can spare/waste the extra on getting a raid card do it

KePSuX · Post by **KePSuX** » Tue Jan 20, 2004 9:07 pm

one more question, the 3ware card everyone has mentioned...will it support two raid arrays on one card (ie 2x250g RAID 0 along with 2x80g RAID 0) or would I need two seperate controllers to pull this off?

kormoc · Post by **kormoc** » Tue Jan 20, 2004 11:31 pm

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KePSuX · Post by **KePSuX** » Mon Feb 16, 2004 5:48 pm

I picked up the mentioned 3ware card and am working on my server setup with it. Im amazed at how well this card works and would reccomend it to anyone. Thanks for the help guys!

edit:

Is it possible to run two of these cards in one system?

kormoc · Post by **kormoc** » Mon Feb 16, 2004 6:41 pm

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cirrus · Post by **cirrus** » Sun Feb 22, 2004 12:41 am

Hi,

congrats to your new 3Ware system!
I'm running a 2.4 Gentoo System with a 3Ware 7000-2 now and tried to upgrade to 2.6!

What kernel options did you switch on for the 3Ware controler?

My fresh compiled 2.6 stops with kernel panic because I did't point to the right boot device (with kernel 2.4 it was sda11).

sda11 seems to be gone with kernel 2.6.....but maybe I forgot to switch some more 2.6 kernel options?!?

Thanks for help.

KePSuX · Post by **KePSuX** » Sun Feb 22, 2004 1:57 am

Under

Code: Select all

Device Drivers  ---> SCSI device support  --->  SCSI low-level drivers  
[*] 3ware Hardware ATA-RAID support.

I'm not sure if this part is needed as it's not using drivers for the writting to the RAID, but I wen ahaead and added it anyways.

Code: Select all

 Under Device Drivers  ---> Multi-device support (RAID and LVM)  
        [*] Multiple devices driver support (RAID and LVM)   
        <*>   RAID support                                           
        < >     Linear (append) mode                                 
        < >     RAID-0 (striping) mode                               
        <*>     RAID-1 (mirroring) mode                              
        < >     RAID-4/RAID-5 mode                                   
        < >     RAID-6 mode (EXPERIMENTAL)

Passe-Poil · Post by **Passe-Poil** » Sun Feb 22, 2004 2:05 am

The unsupported RAID controllers in 2.6.x are mostly the cheap, integrated ones like the Promise PDC20276.

JetAce44 · Post by **JetAce44** » Sun Feb 22, 2004 2:30 am

I'm having trouble with my 3ware 8506-4LP (4 port, SATA, 64bit PCI slot). I've compile all the necessary things into my kernel, but I have no idea where the actual drive is in /dev. I do have the drive previously formatted as a logical NTFS volume of 600gb (4x WD 200gig

), and when I try to mount the device (md0), I get an error that it cant read the superblock.

During the boot up, I get the following:

Code: Select all

scsi0 : Adaptec AIC7XXX EISA/VLB/PCI SCSI HBA DRIVER, Rev 6.2.36
        <Adaptec 2930CU SCSI adapter>
        aic7860: Ultra Single Channel A, SCSI Id=7, 3/253 SCBs

(scsi0:A:3): 20.000MB/s transfers (20.000MHz, offset 15)
  Vendor: PLEXTOR   Model: CD-ROM PX-40TS    Rev: 1.13
  Type:   CD-ROM                             ANSI SCSI revision: 02
3ware Storage Controller device driver for Linux v1.02.00.037.
scsi1 : Found a 3ware Storage Controller at 0x1010, IRQ: 21, P-chip: 1.3
scsi1 : 3ware Storage Controller
  Vendor: 3ware     Model: Logical Disk 0    Rev: 1.0 
  Type:   Direct-Access                      ANSI SCSI revision: 00
sr0: scsi-1 drive
Attached scsi CD-ROM sr0 at scsi0, channel 0, id 3, lun 0

I included the SCSI part, because what I dont get is that it says the SCSI card is scsi0 and the 3ware card is scsi1. I'm sooo confused right now! Help!

KePSuX · Post by **KePSuX** » Sun Feb 22, 2004 2:54 am

JetAce44 wrote:I'm having trouble with my 3ware 8506-4LP (4 port, SATA, 64bit PCI slot). I've compile all the necessary things into my kernel, but I have no idea where the actual drive is in /dev.

Silly questionn- Have you tried /dev/sda1 or /dev/sda2 ?

JetAce44 · Post by **JetAce44** » Sun Feb 22, 2004 3:39 am

KePSuX wrote:
JetAce44 wrote:I'm having trouble with my 3ware 8506-4LP (4 port, SATA, 64bit PCI slot). I've compile all the necessary things into my kernel, but I have no idea where the actual drive is in /dev.
Silly questionn- Have you tried /dev/sda1 or /dev/sda2 ?

Nope, nowhere to be found

Thats where I was expecting to find it.

kormoc · Post by **kormoc** » Sun Feb 22, 2004 3:03 pm

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JetAce44 · Post by **JetAce44** » Sun Feb 22, 2004 5:05 pm

Could my problem be that since I have SATA drives, I have to compile generic SATA support into the kernel?

Kormoc- did you compile the disk support in to the kernel, or as a module? Right now I have it compiled as a module....

kormoc · Post by **kormoc** » Sun Feb 22, 2004 5:30 pm

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JetAce44 · Post by **JetAce44** » Sun Feb 22, 2004 5:37 pm

kormoc wrote:
JetAce44 wrote:Could my problem be that since I have SATA drives, I have to compile generic SATA support into the kernel?

Kormoc- did you compile the disk support in to the kernel, or as a module? Right now I have it compiled as a module....
No, it shouldn't matter if your drives are sata or pata. They will just show up as normal scsi drives to the kernel as far as I know. I compiled the disk support into the kernel. Might want to try that

Gonna try that right now. Gah, I'm on kernel recompile #20 or #21. All those just trying to get all of this support built in. Grrr.

Another interesting thing is that I'm also trying to get my ipod working with my puter, and /dev/sda isnt showing up for that either. I have no idea whats going on. I'll post later if I get everything working or not.

kormoc · Post by **kormoc** » Sun Feb 22, 2004 6:04 pm

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JetAce44 · Post by **JetAce44** » Sun Feb 22, 2004 11:18 pm

kormoc wrote: I'm really sure this will fix it then, cause the ipod uses scsi disk support as well

Yup, it did the trick. I just spent the better part of the day getting everything backed up from the raid array. I managed to pack my main windows/gentoo disk and my 20gb ipod, and still wasn't able to back everything up (mostly movies, I can always grab them from my friend).

Array is now formatted reiserfs and running happily. Ipod is now working too!
Thanks for the help guys.

KePSuX- sorry to sort of crap on your thread, glad we both got our things running. Sweet card huh?

RAID question

RAID question

Re: RAID question

Promise PDC20276 Bad Choice