<div dir="auto">Hi Chris,<div dir="auto"><br></div><div dir="auto">Remounting the drive read only is a standard error handling process for a disk experiencing certain errors </div><div dir="auto"><br></div><div dir="auto">The smartctl test is performed by the drive itself, good news : it's probably not the drive, however I've had drives that were clearly failing happily do these tests (probably an issue on their connector etc)</div><div dir="auto"><br></div><div dir="auto">USB cables are pretty notorious for being flakey etc</div><div dir="auto">Have had them work with some drives and not others, total pita </div><div dir="auto"><br></div><div dir="auto">Rsync over a large volume , particularly with lots of small files and directories, is a pretty brutal stress test of several subsystems. </div><div dir="auto"><br></div><div dir="auto">/Chris </div></div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Thu, 20 Mar 2025, 10:26 am Chris McCormick, <<a href="mailto:chris@mccormick.cx">chris@mccormick.cx</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi,<br>
<br>
Thanks for your reply.<br>
<br>
smartctl seems to think the hardware is fine. I did smartctl -a and it <br>
reported nothing unusual. I also ran a self test and this was the result:<br>
<br>
$ sudo smartctl -l selftest /dev/sdb<br>
smartctl 7.2 2020-12-30 r5155 [aarch64-linux-6.1.21-v8+] (local build)<br>
Copyright (C) 2002-20, Bruce Allen, Christian Franke, <a href="http://www.smartmontools.org" rel="noreferrer noreferrer" target="_blank">www.smartmontools.org</a><br>
<br>
=== START OF READ SMART DATA SECTION ===<br>
SMART Self-test log structure revision number 1<br>
Num Test_Description Status Remaining <br>
LifeTime(hours) LBA_of_first_error<br>
# 1 Short offline Completed without error 00% 6625 <br>
-<br>
<br>
If the drive or the USB hub was overheating would that cause IO errors? <br>
I should also mention that the OS seems to remount the drive a read only <br>
once this happens.<br>
<br>
Chris.<br>
<br>
<br>
On 20/03/2025 08:09, Chris Hoy Poy wrote:<br>
> Hi Chris<br>
> <br>
> If it's timing out with IO errors, you probably have a hardware problem <br>
> somewhere in the mix.<br>
> <br>
> Cable , connector, hub or USB hard drive (probably the destination drive <br>
> by the sounds of it).<br>
> <br>
> Shouldn't matter which software you use to copy (dd, rsync etc) - though <br>
> very different technical processes, if it's dropping data somewhere then <br>
> they will bomb out.<br>
> <br>
> Cheers<br>
> /Chris<br>
> <br>
> <br>
> On Thu, 20 Mar 2025, 8:03 am Chris McCormick, <<a href="mailto:chris@mccormick.cx" target="_blank" rel="noreferrer">chris@mccormick.cx</a> <br>
> <mailto:<a href="mailto:chris@mccormick.cx" target="_blank" rel="noreferrer">chris@mccormick.cx</a>>> wrote:<br>
> <br>
> Hey all,<br>
> <br>
> Unfortunately I couldn't make it to the recent RPi meetup, otherwise<br>
> that would have been a good place to ask about this.<br>
> <br>
> Anyway, I have an RPi with a powered USB hub and two USB hard drives<br>
> plugged in doing backups. The second drive is a mirror of the first<br>
> which I have traditionally done with rsync. I recently replaced one of<br>
> the drives and I now need to mirror the full drive to the new drive.<br>
> I've been using rsync to do this but it takes ages just to do the<br>
> initial diff and craps out after a while with IO errors and unmounts<br>
> the<br>
> destination drive. The total size of data is 2.3Tb.<br>
> <br>
> What is a good way to do a fast copy of all of the data on one USB<br>
> drive<br>
> to the other? I'd prefer not to have to stuff around with partitions if<br>
> possible as they have slightly different partitions on each drive and<br>
> different labels etc.<br>
> <br>
> LLMs were no help at all with this so I'm relying on the PLUG brains<br>
> trust! 😅 Thanks for any suggestions.<br>
> <br>
> Chris.<br>
> <br>
> -- <br>
> <a href="https://mccormick.cx/" rel="noreferrer noreferrer" target="_blank">https://mccormick.cx/</a> <<a href="https://mccormick.cx/" rel="noreferrer noreferrer" target="_blank">https://mccormick.cx/</a>><br>
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</blockquote></div>