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Retain non-raid drives, with new Raid drives
I have a Dell 2850, and admit I am not real Admin person, so trying to get through this.
Originally it had 2 73GB drives, in a SCSI only configuration, so C: and D:. I am running out of space, so bought 4 300GB drives to add in a Raid 5 configuration.
But initially, I do not want to change the configuration of C: and D:.
I have gone into the BIOS and confirmed that I can set it to use RAID. And then rebooted and went into the PERC config (ctrl-M). I see how to set up the RAID 5 array, using the menus.
I also see how it shows RAID CH-0 and SCSI CH-1 under the setup. Currently all 6 of my drives show under RAID CH-0, but nothing shows under SCSI.
I am not sure how to keep the 2 non-raid drives available, especially since C: contains the OS. I have read elsewhere that I might be able to define each as a separate RAID 0 array (with 1 drive each). If I do that, will my OS stay intact, and just boot up? Or do I need to somehow 'move' these 2 drives over to the SCSI CH-1 side?
I didn't want to attempt this RAID 0 config until I am certain I can do it without wiping out the OS and other data.
I hope I have explained it clearly. Any feedback is greatly appreciated.
theflash1932
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July 31st, 2013 15:00
First, if you create a RAID 0 with a non-RAID drive, it will NOT boot - the RAID headers will overwrite the boot files and/or partition tables. Switching between RAID/non-RAID is a destructive process.
Second, the SCSI A connector/cable supports the 6 drives on the backplane. Generally, SCSI B would be used for a non-backplane device, like a tape drive, etc. In order to use the second channel for hard drives on the backplane, you must have a "daughtercard" installed that splits the backplane. With this card installed, you will have drives 0 and 1 on channel A/0 and drives 2-5 on channel B/1. HOWEVER, You can't set channel 0/A to non-RAID - only channel 1/B can be set to SCSI; the first channel is locked in RAID mode when the embedded RAID controller is enabled.
If you look around you might find a better price, but it was a roughly $200-300 upgrade back when the 2850 was shipping:
www.xbyte.com/ProductDesc.aspx
Keep in mind that even with this, you must have the second cable from the riser to the backplane for SCSI B. Even so, you would only be able to put 2x300 in RAID 1 on channel 0/A ... all other drives would be non-RAID/SCSI mode.
One other problem ... I don't think you will have the option to make the SCSI controller the preferred boot device if RAID is enabled, but I'm not sure about that.
theflash1932
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16.3K Posts
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July 31st, 2013 19:00
Yeah, I think it probably isn't worth the headache and effort. I would just plan to reinstall or do a backup/restore.
Given your drive assortment, the RAID 1/RAID 5 combination like you mentioned would make the most sense (unless you did a RAID 10 with your 4 drives). Depends on what you are doing and if performance is more or less important than disk space.
hiker99
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July 31st, 2013 17:00
Thank you for the reply.
Sounds like I might be out of luck doing what I wanted to do. I guess I am better off biting the bullet, and re-install the whole OS, and applications, in a proper raid configuration, probably with OS on the 2 x 73GB (Raid1), and 4 x 300GB in Raid 5.
Does that seem like an OK configuration, considering the differences in the hard-drives?
hiker99
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July 31st, 2013 21:00
Thank you for the feedback.... for me, the RAID 1/RAID 5 will probably work the best in the long run.