Raid setup for 5 HDs...

[Maniac]

Hello .

I got 5 x 72 GB disks in an new server here. I want the following raid setup.

Array 1

Disk 1 & 2 = Raid 1 + 0 (Mirroring, if one drive fails, server runs on the second drive untill drive 1 is replaced. Im planning to have the OS here)

 Array 2

Disk 3 & 4 & 5 = Raid 5 (If one drive fails, the server still runs and dont loose any data, just replace the failed disk and the data gets re-written onto the failed drive, this is the storage array).

I have no problems setting up the first array as i want it.

But i cant setup the second array.

Dont know what im doing wrong. I should be able to run Raid 5 on 3 disks only... When i create the second array with the 3 disks it only lets me use raid 0.

Any clues?

Edit : Oh, i should mention that just for testing purposes, i created one array with all five disks in it, and still i couldnt choose Raid 5.

[Heater]

What is the Raid controler that you are using, and how are you creating the LUNS,

disk 0,1 as Raid 1 (Hardware or Software raid?)

disk 2,3 & 4 as Raid 5

Is the correct?

[Terror]

Originally posted by Maniac
Hello .

I got 5 x 72 GB disks in an new server here. I want the following raid setup.

Array 1

Disk 1 & 2 = Raid 1 + 0 (Mirroring, if one drive fails, server runs on the second drive untill drive 1 is replaced. Im planning to have the OS here)

 Array 2

Disk 3 & 4 & 5 = Raid 5 (If one drive fails, the server still runs and dont loose any data, just replace the failed disk and the data gets re-written onto the failed drive, this is the storage array).

I have no problems setting up the first array as i want it.

But i cant setup the second array.

Dont know what im doing wrong. I should be able to run Raid 5 on 3 disks only... When i create the second array with the 3 disks it only lets me use raid 0.

Any clues?

Edit : Oh, i should mention that just for testing purposes, i created one array with all five disks in it, and still i couldnt choose Raid 5.

What controller are you using?  Make sure it supports a RAID5 parity stripe setup.

If you are using RAID 1+0, this will take 4 drives.  Raid 0+1 (mirrored stripe) or Raid 1+0 (striped mirror) take a minimum of 4 drives and use half the space for parity purposes.

Terror

[Maniac]

Im not much of an hardware guy but...

Controller card = Smart Array E200 http://h18004.www1.hp.com/products/servers/proliantstorage/arraycontrollers/smartarraye200/index.html

Only type of arrays im able to create from the HP Insight startup thingy seems to be SAS arrays.

Disk types are Serial SCSI if that is an problem.

disk 0,1 as Raid 1 (Hardware or Software raid?)

disk 2,3 & 4 as Raid 5

Is the correct?

Yes that was my intention. If i read the link about the controller right, it should support Raid 5.

[Terror]

Originally posted by Maniac
Im not much of an hardware guy but...

Controller card = Smart Array E200

Only type of arrays im able to create from the HP Insight startup thingy seems to be SAS arrays.

Disk types are Serial SCSI if that is an problem.

 

Yes that was my intention.

From the HP website the Smart Array E200 "can be upgraded with the 128MB battery-backed write cache (BBWC) module for RAID 5. "

Has your card been upgraded to support RAID5?

Aaron E.

PS.  SAS = Serial Attached SCSI

[Maniac]

From the HP website the Smart Array E200 "can be upgraded with the 128MB battery-backed write cache (BBWC) module for RAID 5. "

Has your card been upgraded to support RAID5?

Aaron E.

Hah, No its laying neatly here in its plastic bag here on my desktop.

LoL!

Sorry for that. While i got your attention, my original setup plans seems ok right? disk 1 & 2 mirrored, and 1,2,3 Raid 5 ?

Or would you go another way?

[Terror]

Cool.  Let us know how it goes!   And that first array is probably going to be just RAID1 (mirroring with 2 drives).

Nope, your original setup looks fine.  What is the purpose of the server?  If it's mission critical, then mirrored is best.  If you can stand a bit higher potential of data loss, then RAID5 is good.  There is a bit of a write performance penalty for using RAID5 though, but a read gain.  (over mirrored drives)

Terror

[Maniac]

Im upgrading our Lotus Notes server hardware wise... Its 170 users on the server, server is used for 90% for Mail 10% for database handling.

Got pretty nice hardware for it :

HP DL380G5 Xeon 5120
3GB RAM
5 x 72 GB 15k 2.5 Single Port HP SAS Drives

One idea would to use one Array with  Raid 5 for all disks, this way i save one drive and can toy with an bit more HD space... If i use the originall setup i was thinking about, with two Arrays, then i "loose" 2 disks due to raid purposes...

Im an bit divided if i should do this or not, i know 170 users on this server wont notice that much if i set it up with raid 5 over all the disks.

[Phaser11]

OK,
 On most raid controlers you can only have 1 raid per scsi connector. What you can do is put 2 drives in the RAID and then user the other drives with the operating system convert the drives to virtiual (S) and make them into 1 drive.

[Heater]

Ok,

The controller with the upgrade will do Raid 5 or Raid 1 But not both at the same time,

Assuming you are using a Mickeysoft OS (Windows 2000 or 2003),

I would do the following (software mirror the OS drive) i.e. drive 0 & Drive 1,

This will protect the OS / Application side,

Use the Controller for the Raid 5 assuming  it will allow you do to do so (It should not be a problem as the first drives may still be on the controller But it should work,

If performance is an issue, you will need to add a second controller and split it up.

170 users on Notes with 3 GB of ram is pushing it (Data dependent)

We run Notes in clusters with 16 GB in each and are in the process if phasing it out as it is a performance pig once you hit the terabyte of Data...

Cheers

[Maniac]

Allrighty.

After the upgrade to the card, i had no problem doing the originall raid setup completly hardware wise..

The server has 2 SCSI controllers in it.

I put the first two disks in bay 1 & 2 (SCSI controller 1)

And the remaining disks in bay 6 & 7 & 8 (SCSI controller 2)

Made two Arrays with the original setup wich i posted originally without any problems.

Happy camper!

Thanks for the help