arrowsmyth

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Mar 15, 2005
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look into the 745N to help a small company server problems. I wanted to setup the system with hardware raid with 3 disk in raid 5 and the 4th disk as the hot spare. [ I told the salesman and tech sales]. I was told to look in the software and I should have be able to change it.

When we received it last week, I check the setup 10GB array1 and 116GB array 2. no hot spare. After doing some sofwtare check, The only way to set it up is to reboot and do a [control-A] and destroy the installation. I did that and rest the Array. First Array, 10GB 3 disk. second Array 68 GB 3 disk and last drive as hot spare. I created the image on my laptop and created the boot image on the 64MB pen drive. All went well until during the installation the software shows that I don't have a 4 disk array. After various tries at other configuration, the OS install only wants a 4 disk raid 3 installation.

Talking to tech support, the 3 disk raid 5 is not supported. Supported????? The minimum disk for a raid 5 is three disk. And why does the reinstallation care what kind of array it is? The software should support any possible raid configuration that the hardware raid is setup. If I wanted to raid 1, the software should allow it [ we did many database install in this mode] Not so with this system. The 745N only can be setup in a 4 disk raid 5.

Why did DELL hacked the standard re-installation?

Tech Support told me that we should have bought 770N. It support a hot spare. SO does the 745N if the installation doesn't do a disk drive check.

On the other hand, maybe, the company should have purchase a > $4000 system. But how do I know what limitation DELL has installed on the 770N.

I am not full time at this small company. The company can't afford a full time IT like most small companies. And this 745N is definitely targeted at the small company. Dell should allow any configuration that is allowed on the hardware RAID.
 

chicagodns

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Jan 15, 2012
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You should have left well enough alone. The Dell array controllers (adaptec cards, in this case) are not designed to work like that. As a "small company" device, of course it will not support more exotic configurations. To do so would move it out of the small business target market, and require support personnel that have higher skill levels, and cost more to employ.

Besides, why would you even suggest to your client that they reduce the usable space by 30%? by using a 3 disk Raid5 + Spare. ? Instead of losing 1 drive to parity overhead, they lose 2 (one for parity, one for spare) ... which effectively gives them 1/2 of the capacity they paid for. A poor recommendation, to be sure.
 

ShagNasty

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Oct 14, 2013
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TBH your comment is a bit, well, moronic, losing 50% space is nothing, I run raid 10 stacks with hot-spares, on SSD, you can't waste more money than that, but if you want that box up, whatever, that is a price you pay.

Given the guy is using a 745N I guess the firm didn't have budget for an NetApp filer, UPSs, Fibre attached LTO-5 backup and a dark fibre line to a remote site.

Think you before you post, I am about to slam an old 745N into my mates daughters student house, with 4x2TB drives in ADG, same overhead, does that make me clueless??
The guy posted an easy route for me to change the Raid card over and do what I wanted, so perhaps back off?