[solved] usb hdd in some sectors read speed below 100kb/s

kenshis · 2011-12-13 01:49:10

Hello, i have 3 year old Western digital 3.5 sata 640gb usb external hard. It's failing, i know that, and i'm not planing to store critical data on it.
Western digital says that this usb enclosure does not support sata, but smartctl shows this:

SMART support is: Available - device has SMART capability.
SMART support is: Enabled

some bad stats:
Reallocated_Sector_Ct 0x0033 041 041 140 Pre-fail Always FAILING_NOW 1265

Problem is that it has quite a lot of sectors, where read speed is below 100kb/s. How can i hide those sectors from os? How i understand those are not bad sectors. Am i right?
Can "badblocks" help me?
It seams that "R.I.D. HDD" http://www.jthai.ob.tc/ridscan/index.htm does what i need, but it works only on fat16/32 system.
It looks like "mhdd" http://hddguru.com/software/2005.10.02-MHDD/ could help, but i'm not sure

I found something in http://forum.hddguru.com/can-you-manual … 12076.html about p-list and g-list of bad blocks.

Now i'm filling zeros with dd my free 160gb partition. Then i will run extended smartctl test. But actualy i already have formated that partition few times with ntfs, and in process, it was filled with zeros by default.

As workaround, i thought i will fill out partition with 10mb size chunks, and leave those, that are slow to copy.

Last edited by kenshis (2011-12-14 22:25:46)

stqn · 2011-12-13 16:44:51

badblocks doesn't take into account the time taken to read data to determine if it's a good or bad block... However it does already measure the time taken to read (in its "do_read" function) so it should be quite easy to modify it so that slow blocks are considered as bad blocks.

Edit: Now that I think again about this, maybe multitasking during the badblocks check could introduce delays, so one should be careful before listing a block as "bad" just because it took more time than usual to read it...

There's also the possibility that badblocks could help as-is but I'm not sure.

(By the way, last time I had a failing hard drive, I ran badblocks and it found 0 bad block... And then my disk has worked fine even since (but I don't use it much since I don't trust it anymore.))

Last edited by stqn (2011-12-14 22:30:48)

R00KIE · 2011-12-14 10:40:22

Get rid of that disk, with so many reallocated sectors I'd say that disk will probably die sooner rather than later, on top of that the problem may spread to sectors that are still good now so you will continue to have problems.

kenshis · 2011-12-14 22:18:22

@stqn, very useful info. I fink i will try to hack a bit badlocks.

Unfortunately, 10gb partition took more than 5h to format with checking for badlocks. So 640gb hard will take too long in that sense, that i will most likely dramatically decrease life time of dying hdd. And my hard is pretty much failing as R00KIE said.

So i thing i will go with my plan to fill partition with 10mb data chunks, and maybe i will get some working time from it, if no - oh well.

Before i started to research this problem, had no idea about badblocks, so to others: if for some reason s.m.a.r.t does not fix bad or slow blocks problem, you can invoke badblocks from e2fsck, mkfs and maybe others. It will write info on file-system which blocks don't use, of course, after partition deletion, you will have to repeat it.

I think extended s.m.a.r.t test should mange all bad blocks, but unfortunately i can't run it. Most probably because it's a usb hdd, or maybe it's too damaged.

Alexandre Magno · 2014-07-17 15:16:12

Hello, kenshis! Did you make the hack in the badblocks? Do I may see it?

ewaller · 2014-07-17 15:50:03

This thread is 2 1/2 years old and we have not heard from kenshis in a while and much has changed in that time. I will leave this thread open for now on the off chance than kenshis responds. If we want to pick this conversation, please start a new thread and link back to this one. Thanks.

https://wiki.archlinux.org/index.php/Fo … Bumping.22

Arch Linux

#1 2011-12-13 01:49:10

[solved] usb hdd in some sectors read speed below 100kb/s

#2 2011-12-13 16:44:51

Re: [solved] usb hdd in some sectors read speed below 100kb/s

#3 2011-12-14 10:40:22

Re: [solved] usb hdd in some sectors read speed below 100kb/s

#4 2011-12-14 22:18:22

Re: [solved] usb hdd in some sectors read speed below 100kb/s

#5 2014-07-17 15:16:12

Re: [solved] usb hdd in some sectors read speed below 100kb/s

#6 2014-07-17 15:50:03

Re: [solved] usb hdd in some sectors read speed below 100kb/s

Board footer