External USB Hard Drive suddenly got really slow!!!

[mikearce]

Ive had a Western Digital My Book USB 2TB External Hard Drive for a while. Never gave me any problems.

Today I noticed while streaming video content from it that the stream itself was slower than usual. I went to my imac opened it in finder and it takes forever to even display the folders. I opened one of the folders where I had a bunch of videos and it just keeps reading but wont display them, just keeps reading. Transfer speeds are REALLY slow too.

I went to Disk Utility and verified it and it says everything is OK. I even booted the imac from the Lion Recovery Disk and tried it again. Same thing. Says everything is perfect! I ejected it and plugged it into my MacBook Pro and same thing. Extremely slow both while reading and writing or transfering files.

I have other WD usb external hard drives and they all work fine. Im starting to lose it cuz I have a lot of important stuff in there.

Any help would be really appreciated!



iMac specs:

27-inch, Mid 2011
Processor 3.4 GHz Intel Core i7
Memory 16 GB 1333 MHz DDR3
Graphics AMD Radeon HD 6970M 2048 MB
Software Mac OS X Lion 10.7.3

 

[murphychris]

I went to Disk Utility and verified it and it says everything is OK.

Try a different cable and also get anything important off of it as soon as you can.

"Verify" only checks the directory structure. That can be fine as long as the disk is successfully performing error detection and correction and what you're describing is a disk that's getting a lot of read errors, but is correcting them. So the file system says "I'm fine" even though the disk is having issues.

When you click on the disk icon in Disk Utility, at the bottom what does it says for SMART Status?

 

[simsaladimbamba]

You can use the following applications to benchmark the speed of your HDD to see, if it is that slow:

• AJA System Test
• Blackmagic Disk Speed Test
• Xbench

Also make a backup of that data, if it is that important.

Here is how I backup my important data:

I have one 500 GB HDD for my photographs (digital and analog) libraries and editing documents, one 500 GB HDD with my personal video footage in an editing friendly format.
Both 500 GB HDDs get backed up to one 1 TB HDD via CarbonCopyCloner.
And that 1 TB HDD gets backed up to another 1 TB HDD via CarbonCopyCloner.
Therefore I have three copies of my important data.

 

[chrisg02176]

Ive had a Western Digital My Book USB 2TB External Hard Drive for a while. Never gave me any problems.

Today I noticed while streaming video content from it that the stream itself was slower than usual. I went to my imac opened it in finder and it takes forever to even display the folders. I opened one of the folders where I had a bunch of videos and it just keeps reading but wont display them, just keeps reading. Transfer speeds are REALLY slow too.

I went to Disk Utility and verified it and it says everything is OK. I even booted the imac from the Lion Recovery Disk and tried it again. Same thing. Says everything is perfect! I ejected it and plugged it into my MacBook Pro and same thing. Extremely slow both while reading and writing or transfering files.

I have other WD usb external hard drives and they all work fine. Im starting to lose it cuz I have a lot of important stuff in there.

Any help would be really appreciated!



________________________________________________

Hey I was just wondering if you got this issue solved and if so, how did you do that? I have the a WD 2 TB drive as well and this just happened to me out of the blue. My laptop is very fast but recently while watching Seinfeld videos from the drive, if became choppy and eventually just stops playing. this happened a few nights in a row. I even defragged my computer drive, thinking that may have been the issue. I don't understand why this is happening. Please help me out if you found a solution

 

[mwhities]

I did a lot of data (400Gs+) moving last night and I noticed a big slow down accessing it after. I also installed Lion installer on it to instal Lion on my Raid0 320s and it took 15 minutes for the install screen to come up. It kept stopping saying to try reinstalling.

I googled that and it said to reset PRAM. After I did that, it installed properly and seemed to transfer faster. Maybe that that and report back.

 

[brand]

You could pull the drive from the enclosure and run SpinRite on it.

 

[murphychris]

I'd sooner suspect mds or mdworker (spotlight processes) were involved in updating the index on that disk, which slows things down immensely. Or a backupd process from/to this disk which also slows things down immensely. So I'd go to Terminal and run the top command. Or look at Activity Monitor with the top pop-up menu set to All Processes, then click on %CPU column so it sorts by most to least CPU usage. See what process is hogging the most processes, and if it's possible that process is using the affected drive.

Another possibility is that the disk has developed marginally bad sectors. This will cause long delays as the drive firmware ECC corrects for the problem. So long as the read is eventually successful, an error usually isn't logged. But you could run 'sudo dmesg' from Terminal and search through that pile of complexity for something related to the /dev/diskX device in question. If you don't know what X is for your disk, then use 'diskutil list' for a listing.