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I've got a Mac mini running server and a few people connecting. This is working fine and no issues so far. I bought a sharkoon USB external 5 bay RAID box and connected to the server and setup shares. That worked for a while but then the Mac mini decided to randomly drop the USB connection and give me a warning about not ejecting drives could lead to data corruption issues. After that if I reconnect the drives, it'll do it again and just not play ball.

Biggest issue of course is that the usb drive just doesn't stay "connected". I read that some people had problems with some of their USB 3.0 cables but I wanted to check if anyone has done anything like this before?

Related to this is when the usb drive disconnects and a user is currently browsing their shares, they'll get kicked from the server and can't re-authenticate, it just keeps saying "connection failed" even when the drive is plugged back in. I can't seem to find anyone with the same issue or a definitive resolution and apple aren't willing to help at all.

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Okay, so after a number of months of the issue I've finally resolved it. The 5 drive external caddy I was using had hardware RAID on it and each drive (5 of) was a 2TB WD Green.

Here's what I did:

  1. Turned off hardware RAID on my caddy (passthrough only).
  2. Formatted the drives as follows:
    1. Format the first physical drive as OS X Extended (Journaled) with no RAID and at it's full capacity (2TB).
    2. Format the rest as OS X Extended (Journaled) using OS X disk utility's RAID option.
  3. Turn ON "Put hard disks to sleep whenever possible" within System Preferences->Energy Saver
  4. Then share them using OS X Server.
  5. Turn file sharing On.

For some reason if the first physical drive is part of a hardware/software RAID, OS X ejects it after a small amount of use. Also if the caddy or drive has firmware that puts it to sleep, and the OS X system isn't expecting drives to go to sleep (in other words, if step 3 above isn't done) this causes error code -50 and puts everything in the drive as read only.

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