Arch Linux

lgolebio

Member

From: Poland / Wroclaw

Registered: 2008-07-28

Posts: 101

USB disks problem

Hi
I have two  2.5" hard drives in  "USB 2.0 SATA Hard Drive HDD Case". I use them as my backup. The problem is that sometimes, when I copy files from my computer to one of these USB-sata disks, the system changes the name of the connected disk. For example when I plug it in it recognizes my USB-sata disk as a /dev/sdb and after copying some files to this drive it randomly changes to /dev/sdc. Then copying files crashes, and I have to repeat the whole copying process. The second problem is that I've noticed some change in beahaviour of these drives. The Load_Cycle_Count has changed. How I know that ? I just hear that disk are "parking" over and over again. Sometimes coupple of times per minute ! (The clicking parking noise)
I have 2 different USB cases, one is 14cd:6116 Super Top M6116 SATA Bridge and the second is 125f:a94a A-DATA Technology Co., Ltd. On both of them these problem exists.

Is it udev related problem ?

spec: (the system is up to date)
1. XFCE - latest
2. Linux 3.1.0-4-ARCH
3. latest packages.

I can do....

hdparm -B 254 /dev/sdx

and it helps with clicking noise, it will never click again. but I have to do it every time I plug  the disk in.  Still it doesn't solve the problem with  random device name change.

Last edited by lgolebio (2011-11-13 18:01:37)

NClement

Member

Registered: 2011-11-13

Posts: 12

Re: USB disks problem

I have no idea about the clicking, but as for your first problem: try giving these hard drives unique, descriptive labels with e2label or xfs_admin and then edit /etc/fstab so it refers to the devices by their labels.  Here is my fstab:

# 
# /etc/fstab: static file system information
#
# <file system>	<dir>		<type>	<options>	<dump>	<pass>
tmpfs		/tmp		tmpfs	nodev,nosuid	0	0
LABEL=rootdisk	/ 		ext4 	defaults 	0 	1
LABEL=swapdisk	swap 		swap 	defaults 	0 	0
LABEL=userdisk 	/home 		ext4 	defaults 	0 	2
/dev/sda1	/mnt/windows	ntfs-3g	defaults	0	2		

for example.

Disclaimers: (1) make a backup of fstab, (2) This might do something funny if those devices aren't plugged in when you boot up (3) I am not confident in my choices for the last two columns in fstab.

Let me know if this works!

Last edited by NClement (2011-11-15 06:18:49)

tomk

Forum Fellow

From: Ireland

Registered: 2004-07-21

Posts: 9,839

Re: USB disks problem

Relevant wiki page here.

You can configure a udev rule to run that hdparm command every time you plug the devices in.