August 7, 20232 yr I've been reading that you shouldn't use USB connected drives for UNRAID, but only direct SATA connections, because USB can drop out, which causes problems with UNRAID. Not knowing this, I already have 8 drives on a USB hub connected to a Lenovo think station. Would it be any better if the drives were placed in a drive enclosure, and all SATA connected there, but the enclosure then connects to the think station via USB 3 cable? Is that exactly the same risk of USB dropping? Would I need to crack open the think station and create a SATA connection and get a drive enclosure that connects to the think station via SATA? I don't know when I'll have the money to set all that up, but when I do, I want to make sure it would actually make a difference.
August 8, 20232 yr Community Expert 8 hours ago, gathly said: Would it be any better if the drives were placed in a drive enclosure, and all SATA connected there, but the enclosure then connects to the think station via USB 3 cable? Nope.
August 8, 20232 yr Community Expert Solution No, it is the same problem as before. Now you fondle the maximum speed through one hub (which devides it among all connected ports) afterwards the controller in that enclosure does the same. Both "solutions" slow down drives enormously, they should not be considered at all. The other thing is that the usb driver in linux sometimes gets a hickup and resets the controller and/or the ports. This leads to massive interruptions even with possible loss of data! AVOID AVOID AVOID!!!
August 8, 20232 yr Author 4 hours ago, MAM59 said: No, it is the same problem as before. Now you fondle the maximum speed through one hub (which devides it among all connected ports) afterwards the controller in that enclosure does the same. Both "solutions" slow down drives enormously, they should not be considered at all. The other thing is that the usb driver in linux sometimes gets a hickup and resets the controller and/or the ports. This leads to massive interruptions even with possible loss of data! AVOID AVOID AVOID!!! Looking at various 10-bay drive enclosures, it doesn't seem like any of them have a SATA out port, so what's the best way to do this?
August 8, 20232 yr Community Expert 38 minutes ago, gathly said: t doesn't seem like any of them have a SATA out port, so what's the best way to do this "best" would be a sata cable from the main computer to each drive, but usually this is not possible (lots of cables) next best (and most common) is to use a SAS controller. Each SAS line can handle 4 SATA drives, so you have either only one or two cable between the computer and the external case (for 4 or 8 drives, but not for 10) These SAS cables exist with different plugs, for internal or external connections. You need to see what kind of plug the controller and the case have and buy an appropriate cable. (these are very thin cables, smaller than a single SATA cable). But this is the data connection only, the external case must supply power for the drives! For up to 8 drives you will get full speed (even for SSDs), controllers which offer more ports are either expensive of feature "port multiplexers" which slow down access too. But if you want 16 or more drives you have to live with them. (Warning! for UNRAID you need to buy a SAS controller flashed into "IT" mode, else it will not work! Search this forum for more infos about this!) Edited August 8, 20232 yr by MAM59
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