spencer785

Does unraid support external hard drives?

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Hi there I can't seem to get a straight answer on whether unraid support external hard drives in the array, please help. Thanks 

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Yes.  esata / usb.  Although USB is not particularly recommended

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How do you add them to the array and as long as its usb 3 isn't it fast enough. 

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Many USB -> Sata Bridges do not pass through SMART attributes, etc.

 

AFAIK You just add them as per normal.  USB3 support added at least 2 years ago.

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Thanks for the quick response once last quick question. If I bought a multi bay enclosure with only 1 usb 3 port would they all be detected. Thanks 

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58 minutes ago, spencer785 said:

If I bought a multi bay enclosure with only 1 usb 3 port would they all be detected.

What you are proposing, if it does work, would be extremely slow, and unsafe for your data.

Whether or not they would all be detected would be determined by the specific enclosure, but I don't know of any way to know beforehand, you will have to test.

 

It may work, but it's definitely NOT recommended.

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Just wanted to keep you guys updated. I bought two external usb 3 enclosures and installed two spare drives a 4tb and 3tb. They are clearing right now and averaging 160mb/s each. 

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This is good try, rather low cost to add extra bay. USB storage could work stable but not recommended,  I use one multibay (market EOL) for longtime.

 

I notice you attach 2 enclosures, due to you use 2 different size/model disk, then identify haven't problem. But if use 2 same model and size disk, identify may got problem.

 

Recently I found those USB multibay enclosures price raise a lot. When price drop enough, I may buy one for expansion/spare/fun.

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Ya I had no more room to add extra bays, as I already have 4-5 bay hot swap cages in my antec 1200 case. I now have 22 array drives and 2 ssd cache drives, 127TB currently. 

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Alright they finished clearing and are now mounted in the array. Couple things I noticed the temp and smart info isn't passing through. That won't really affect anything will it?

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6 minutes ago, spencer785 said:

Alright they finished clearing and are now mounted in the array. Couple things I noticed the temp and smart info isn't passing through. That won't really affect anything will it?

 

On 4/14/2018 at 10:08 AM, jonathanm said:

unsafe for your data.

 

Since unraid requires flawless reads from ALL devices other than the failed drive to reconstruct said failed drive, you are putting your entire array at risk by not being able to monitor the condition of those drives.

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2 minutes ago, spencer785 said:

If the drives in the usb enclosures encounter a read or write error will unread still be able to red ball it. 

Sure. That's not an issue. However... many times when a USB interface errors, it will kill the data stream from all the devices on that interface when it issues a USB reset command. So it's fairly likely that if you do have a problem, it will red ball all the USB drives. Then, without SMART data, it will be difficult to figure out which drive(s) may or may not actually have an issue.

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2 minutes ago, spencer785 said:

If the drives in the usb enclosures encounter a read or write error will unread still be able to red ball it. 

 

unRAID will disable any disk that has a write error. It doesn't disable a disk for read errors. Often if unRAID can't successfully read a disk after several attempts, it will attempt to write the data back to the disk from the parity calculation, and if that write fails it would be disabled. But otherwise read errors won't disable a disk.

 

But since you can't monitor the SMART of the disks, you can't get notifications of impending issues with those disks. You do have Notifications setup don't you?

 

And as mentioned, all drives must work well for parity to be able to reconstruct a disk. You can have a disk problem that doesn't cause it to be disabled, but could still be a problem when trying to reconstruct another disk.

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Have you considered upsizing some of your disks? 127TB is attainable in fewer disks than you have, and fewer disks means fewer opportunities for problems, both during operation, and, as you have now, in configuring a system.

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Is it a problem with the enclosures I have or a driver problem why the smart data isn't passing. Also is it possible that bios setting or unraid setting could make smart work. 

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It's usually an enclosure problem, but like most already told you USB is a bad idea for array use, even if SMART is passed they usually have very bad error handling, if you need to use external use a SAS enclosure.

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Yes I know it's bad idea to use usb in the array. Do you think it's worth trying other enclosures to see if they can pass smart info? or should I not bother because of bad handling like you said. Thanks

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I think eSATA is worth considering as an option. It works well for me. The only thing I don't like is the cable and its connectors but if you make sure it's protected it isn't a problem.

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For single drives yes.

For multiple drives, qualified yes - ok for limited media access, but parity checks and drive rebuilds will definitely suffer slowdown. And getting a stable controller with proper PM support can be very hard.

 

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For single drives, certainly. Also for up to four drives, in my experience. Parity check speeds are slightly compromised but still very acceptable IMO. I found a good quality case with a port multiplier that passes all the SMART information and a fast compatible eSATA card. The only thing I wouldn't recommend is using it for a parity disk.

 

 

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