RAID Configuration (RAID 10 or RAID 1/10 ?)

[austingecko]

Configuring a PE 2850 rack. We'll be running Red Hat ES 3.3 (possibly switching to SUSE Enterprise 9) with a Java application server and SQL database on a single system. We're sold on using RAID 10 for the applications/files.

The system configuration includes Xeon 3.6 x 2 and 8GB RAM.

Should I configure the drives as follows:
6 x 146GB, U320, SCSI 10K at RAID 10 (OS + applications); or
4 x 146GB, U320, SCSI 10K (applications) at RAID 10 + 2 x 146GB, U320, SCSI 10K (OS)?

On the second configuration, we would use a 2+4 Split Backplane Daughtercard. Do we then need a controller with 2 internal channels (PERC4/DC)? Or are we ok with the embedded controller, PERC4ei?

Also, if we go with the second configuration it may make sense to use 2 x 73GB SCSI 15K and then 146 GB 10K on the RAID 10?

I wish Dell had larger hard drives available for configuration. Thanks in advance

 

[austingecko]

I should add one reason pulling us to a single RAID 10 configuration is that I've read system read and write speed will increase as the amount of storage (with the drives being the same) is increased, with RAID 10. Also, the OS will rarely require read and write access, and a single RAID 10 would likely increase overall storage space for the applications and files.

The reason we are interested in a RAID 1/RAID 10 configuration is that it's been a rule of thumb to have the OS separate.

 

[johnny99]

Just as a hunch I would go for the 6 x 146 and a raid 10.
More drives in the raid 10 will give you more speed.

I implemented my first 2850 with the PCI-Express bus in production last week.
We always use the spilt backplane and have been doing so since we started using 2550's 4 years ago.
And we just use the embedded controller. (Check with Dell just to be 100% sure)

In our installation we always use raid 1 + one hotspare, but that is because we only keep the operatingsystem on the local drives. The rest of the data is on our SAN.

/johnny

 

[austingecko]

Thanks, we'll go with 6 x 146 on raid 10, I read more materials showing how additional drives on raid 10 gives more speed.

The drives will use the PERC4ei embedded controller.

If we were to add a PowerVault 100T, we'll need to add a 2nd controller? Would a Ultra3 SCSI LVD controller card be sufficient? Not sure there is room...

 

[technome]

Yes, you will need to a separate scsi channel for the tape unit; placing a tape unit on a raid channel with disks involved, is the road to data destruction. Are you sure you do not have an onboard scsi interface(s)?
A U3 scsi adapter should be fine.