read/ write operation extremely slow on external USB drive

RAFAL · 12-21-2015, 01:21 AM

Hello All,

I have external portable BD Witer (Model SE506). Since some time I have noticed that read or write operation is extremely slow.
Example: copy around 21 GB from it is estimated to 6 hours !

This drive is connected to USB 2.0 port (all USB ports on my ZOTAC are USB 2.0). The same device is not slow on Windows machine, so it cannot be physical defect.
I have read something about DMA versus PIO http://www.linuxquestions.org/questi...-142224-print/, but when I try to check I get error:

Code:

sudo hdparm -d /dev/sr0
/dev/sr0:
 HDIO_GET_DMA failed: Invalid argument

What else can I check?
The speed is really annoying. For burning one BluRay it needed around 14 hours.

My distro on that machine is lubuntu:

Code:

sudo uname -a
Linux zotac 3.13.0-63-generic #103-Ubuntu SMP Fri Aug 14 21:43:30 UTC 2015 i686 i686 i686 GNU/Linux

What can I check or do ?

Regards
Rafal

ondoho · 12-21-2015, 02:19 AM

i'm sorry, are you talking about an external blueray drive?

so you can't just copy to it, you are "burning"???

in any case, 21GB is a lot for usb2.

have you actually performed the action and measured the time yourself?

have you compared the times on the same machine with windows and linux?

the estimate could be more realistic & modest than the one issued by some windows app.

RAFAL · 12-21-2015, 04:04 AM

yes. I was talking about burning operation (K3B software which I am using calls it 'writing' (like selection of 'writing speed') and not 'burning speed')
I think name used here is less important :-)
about the time meassurement - its not about 13 or 14 hours. In both cases its very slow (too slow).
I can attach the screenshot on which K3B shows writing speed 0,2x (this disc should have 2,0x)
also reading is very slow.

could it be physical damage to USB port?
When I compare it with Windows I am talking about the same device, but pluged in to different PC (also USB 2.0 port).

how can I test the drive on linux or check if it is using DMA or PIO ?

ondoho · 12-21-2015, 06:56 AM

maybe you're missing some blueray drivers.
have you researched blueray support on linux in general and on opensuse in particular?

RAFAL · 12-21-2015, 08:33 AM

I have never installed any extra drivers before and it worked fine.
I do not use opensuse anymore. Its on lubuntu. See my first post with outcome from 'uname'

RAFAL · 12-21-2015, 11:54 AM

what I see in dmesg | more is this:

Quote:

[ 3.106186] scsi 2:0:0:0: CD-ROM TSSTcorp BDDVDW SE-506BB TS00 PQ: 0 ANSI: 0
[ 3.109918] sr0: scsi3-mmc drive: 24x/24x writer dvd-ram cd/rw xa/form2 cdda tray
[ 3.109926] cdrom: Uniform CD-ROM driver Revision: 3.20
[ 3.110235] sr 2:0:0:0: Attached scsi CD-ROM sr0
[ 3.111021] sr 2:0:0:0: Attached scsi generic sg1 type 5

any ideas about the issue which I have and how to solve it?

I found some entries like this
http://unix.stackexchange.com/questi...cd-rom-burning
but not much help from it

ondoho · 12-21-2015, 04:34 PM

Quote:

Originally Posted by RAFAL

I do not use opensuse anymore. Its on lubuntu. See my first post with outcome from 'uname'

ok, sorry i missed that.
so, have you made extensive searches? what did you find?

your dmesg output does not suggest that your system is even recognizing it as a blueray?

what about if you fire up k3b, does it even have blueray support? does it recognize the drive as blueray, not just cd/dvd?

there's many more factors influencing burn speed, at least on cd/dvd...