More PC Tech than Emu

[dj_johnnyg]

Since this is the most suitable place for this topic (mods feel free to move) I wanted to probe the knowledge of the board.

At home I have 2 10-bay Fibre channel HDD enclosures. Now the drives I have are about 7 years old, and were used for a massive hospital-wide picture database (Medical imaging), so I am suffering from drives failing left, right & centre.

I want to create a RAID array to store my DivX'd DVDs & MP3s to stream around my house. Now I don't trust the drives enough to use them, and fibre-channel discs are hella expensive, so I've had an idea. I'll use the 19" chassis as a chassis for SATA-2 discs.

So I have 3 options:

1) Run a small mobo in the Chassis (they are full server depth) behind the drives & use an ATX supply (or similar), so creating a mini-file server
2) Use a seperate server, and use the chassis as external drive holders.

Now 1) is fairly easy to do, and I have no problem with this except I would need to build 2 servers, so have to buy 2 lots of everything.

2) is the cheapest option as I can use a server I have already, and just buy enough SATA-2 controllers to run all the discs.

I'm struggling on the power for the Arrays. I have 2 ideas:

Have the array turn off when the Server powers off - Use the pin14 (IIRC) signal to trip 2 PSUs (one in the Server, one in the chassis) if this is possible

Have the array stay Live until I turn it off manually - I can use the dual redundant PSU's in the chassis (Plus I have a few spares) and since they are designed to run 15 drives & fans means I can make the arrays as close to original as possible (just using SATA-2)

So What damage would be caused (if any) by having power still applied to the drives, but the server being off (Similar to having an IDE drive powered, but the IDE cable disconnected)?

What issues would I have from running internal SATA cables from a server externally to the chassis?

Hope this makes sense. I'm just trying to work out what bits I can bin, and which bits I should keep

[Jahya]

It makes a bit of sense. SATA is naturally hot swappable, keep that in mind. If I get the picture correctly, you have an old file server that you want to transfer to a new one.

My suggestion is number 2. If you have a server available, just get a sata raid card, build your new disks/volumes and transfer the data over.

As far as damage to the data during the power issue. I'm not 100% clear on what you mean but here goes. On boot, and array will not damage disks that are powered, with no data connection. They would simply loop in a discovery mode, waiting for the cable. If the array itself is seen in windows, it should be a 'stoppable' item. Use 'safely remove hardware' in windows to stop the array, before removing the data cables and no damage will be done. In this case the drives would have to cycle down completely and back up to discover the connection again.

If you power the server down, the array should technically cease writing. Unless your raid configuration is built onto a card in the array that rebuilds/write parity etc. If your array is controlled by software, on teh server, the array device should be removed when the server shuts down. If that is the case, you can safely have the array power down after the server is fully down.

If you remove the data cables, while the power is on, and the disk is being written to, especially in a raid config, you will get data corruption.

There is no impact to running internal SATA cables externally. Some raid sata cards actually have an external sata port on the metal edge of the card.

I hope this answers your question.