Logical Drive creation Best practices

[damon lane]

Hi all

I have a proliant dl380 G4 with 4 x 36GB disks, and a smart array 6402

Now Im in the porcess of setting this up for a windows 2000 infrastructure and am wondering on Drive array best practices. As I see it I could do either of the following options, but I was wondering if anyone had an idea as to which one is the more preferable

Option a)RAID 5 - 2 logical drives defined at ARRAY LEVEL

1 x Array
2 x Logical drives (1 10GB, 1 remainder space)
OS installed on logical drive one
All other apps/data installed on logical drive 2

Option b)RAID 5 - 1 logical drive defined at array level

1 x array
1 x logical drive (all availabel space)
Let the OS handle the disk partitioning and therefore split the disk at OS level

Now is there any advantage to defining two logical drives at Array level with regard to throughput,read times etc

Im searched high and low to try and find a "best practice" on array and logical drive settings but can only find RAID guides. What Im really after is an explanation as to whether there is any benefit to having multiple logical drives defined at array level

Thanks

[Oleg Koroz]

DL380 G4 maximum 6 drives.
Internal smart array Controller 6i (depend from Model BBWC can be Included)
G4 server would allow you to Configure Simplex and Duplex with Internal or Optional Array controller equally.

Q. If your Server main purpose for read info; why would be necessary use of additional 6402 controller?

If Server intended to run over light Read/Write action: inexpensive way I would recommend to Purchase BBWC for 6i controller and use SCSI backplane as Simplex. If your server performing heavy read/write action recommendation to make SCSI backplane spited for duplex and first two drive for O/S and last up to 4 drives for data with additional Controller (requires additional Drives). Once again last configuration with duplex: smaller drives for O/S like 18Gb and large size hard drives for data. For heavy load you need to keep split between Channels or controller and bus.

If all four drives in the same array and you don't have good backup solution: for O/S make two partitions, first partition 8GB (or 10Gb).
Are you intended to use 6402 for External use?

[e4services]

What was said is similar to what we have. What was suggested in the past was to seperate the OS and the data.
The OS on a separate drive, the data on a RAID 5.
Reason: to seperate OS loss from Data loss.
A corrupted OS will not cause you to not have access to your data.
Some people mirror there OS drive to protect from drive failure, others keep a back up drive copy. Some run the OS drive off the std SCSI controller also to unload the RAID controller, since the OS is "dirty", read and write all the time, virtual memory and such. Some us non-hotswap drives for the OS since they do not care to hotswap the OS, and would take the server down to replace the drive plus it opens up space in the hotswap cage for more data space.

SO there ya go. 2 cents worth

[CG_2]

Damon,

I can't see an advantage. I expect that the performance would be the same. Also, neither one should affect the redundancy.

The only differences I see are beyond performance:
"Option A" If something mucked-up Window's partition table both drives might go down the crapper. 2 drives at the array level would be immune to that, possibly.
"Option B" If you ever might need to resize the partitions with something like Partition Magic you would be SOL.

My standard is to use your "option a". I have only suffered partition table problems like I mentioned that we my own fault. I have however enjoyed easy partition resizing in the past. Also it seems to be the "simpler" approach (not necessarily easier, just ever so slightly less complex).