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Anonymous
USB 3 external HDD issues not present in USB 2. 2017-01-09 06:13:21 Post No.
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USB 3 external HDD issues not present in USB 2. 2017-01-09 06:13:21 Post No.
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I'll try to make this short.
When I plug my external HDD into my PC's USB 3 ports, there are pauses when reading files. A file will partially read, then pause for 10 - 180 seconds (usually about 15 - 30 seconds), then resume copying, maybe multiple times for every file. When it's going, the read speed is fine, quite high actually, about 60 MiB/second. The MD5sums match after copying.
It doesn't do this when plugged into the USB 2 ports. When plugged into the USB 2 ports it reads files at about 30 - 40 MiB/second (which is about max for USB 2), but it doesn't pause, ever.
It only has problems reading files when I'm using a USB 3 port.
I'm using Linux Mint Rosa.
I have USB 3 support enabled in my kernel.
CONFIG_USB_XHCI_HCD=y
Kernel: 3.19.0-32-generic x86_64 (64 bit gcc: 4.8.2)
I have more info I can post if necessary.
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>>58400322
>I'm using Linux Mint Rosa.
found your problem
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>>58400350
While I appreciate the humor of your meme answer, such answers can be given for any circumstance.
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>>58400322
1.) Could be drive caching. It pauses because the HDD actually has to write the data to the disk. There is no need to disable it, as it's increases transfer speed for small transfers, and shouldn't harm large transfers.
2.) The actual SATA-USB controller is broken with UAS, or vise versa. Could also be a kernel issue, as UAS works in some kernels and doesn't in others. Disable UAS by following this thread: https://bbs.archlinux.org/viewtopic.php?id=183190
For me it was the latter, and disabling it from loading for the given USB controller fixed pausing IO operations and timeouts (important, due to risk of data corruption). For me, write speed decreased by ~15MB/s for HDD, SSD not tested.
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>>58400456
Forgive my impertinence, but why not just plug it into the USB 2 port, if the solution is going to reduce the speed on the USB 3 port?
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>>58400554
Because you'll be bottlenecked by USB 2.0 throughput, while the fallback BOT driver on USB 3.0 will still exceed the maximum transfer speeds of mechanical drives. Like I said, I'm not sure of the performance impact on SSDs, but with HDDs speeds are still near maximum, only caching seems to be affected and thus slight performance decrease.
You really don't have much to lose, as to revert simply comment out/delete the file you created and reboot system.
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>>58400456
After disabling UAS on the drive, the problem persists.
I know it's not the speed of my destination drive. I'm writing the read files to my RAM via TMPFS, it has a write speed of over 1GiB/second.
I'm certain that this is an issue with the kernel or software. The drive works perfectly plugged into the USB 2 ports, just at USB 2 speeds.
It also only does this when reading files. It writes them just fine.
Before you came along, I had no idea about the UAS though, so thanks for all your help.
I think I'm just going to give up on this. It's just turning into a waste of time.
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>>58400456
I have managed to FINALLY get it right.
It wasn't updating the right initramfs.
All is well now. THANK YOU VERY MUCH FOR YOUR HELP.
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