How to recover External HD
 

I have "Western Digital Hard disk (160GB)".
When I connected to the server it can mount and also show the contents of the disk.Try to copy some data from it to server.But very slow copy speed. How to recover this disk. Can we take iso or whatever (ghosting) .

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[root@host10 ~]# df -h
/dev/sdc1 150G 96G 54G 64% /newdisk/myhard


[root@host10 ~]#ls

Show all contents of Disk.

It may be as slow as 12MB/S copying the disk. That's what a usb-2.0 port manages under windows typically. If there's not a good cable on it, the port may default back to 1MB/S usb-1.x.

Clonezilla is the best here. I can't talk about the speed, but it's the best at taking a snapshot of your disk. You just need another partition in another disk that is greater in size than the one you are copying from.
Another much simpler option is for you to use gparted. Just copy the entire drive over to another partition and as long as the destination partition is greater it'll go without a hitch.

Where did you get that data from? With a fast USB device (external HDD or a high quality Flash device) not one of the Windows systems I administer for friends (and my Windows install neither) limits itself to 12MB/sec, they all get to the 30-35MB/sec that can be expected as the practical limit of USB 2.0. So I wouldn't call this typical at all.

@pra838: Some questions:
- How slow is "very slow copy speed"?
- What makes you think that it would be faster to copy an image than the actual files?
- Dou you get error messages in your dmesg output regarding that disk?
- Have you tried to use the disk internally to rule out that the controller in the external case is faulty?

About 8 months copying gigabytes of data disks around ~2009. The place had one look at ancient documents and books, and were scanning them. Our data was 400MB - 800MB tiffs (up to 500/day) and various sizes of jpeg (up to 1000 per day, usually 10MB or larger). There was a card reader that spat through about 200 per hour, although these were usually smaller files. Backups were stored on another disk, and you did have to use usb disks, although gigabit ethernet was lazier; but you'd clog that with a 400-500GB copy.

The IT guy (Not me!) was buying 500GB disks by the box(24, iirc) and was on 1Tb sata last heard (2010). He even used to hot swap those ide ones, although I would always turn off to do it.

I'm not a technical guy, but as far as I know both tiffs and jpegs are image formats. Usually images are much slower to copy than text files. It has no bearing on the potential copy speed. For example, whenever I copy text files from one HD to another, I get up to 25 mbps sometimes, but images don't go above 5 - 6 mbps. And this is using the same drives.

The copy algorithm is not aware of the format of the copied file (just because it don't has to), it makes no differences between text files and other formats, so from a technical point of view there should be no difference.

But I always get a slower speed when copying images. I have two internal drives with one serving as a backup. I periodically take a backup and I invariably copy the files over from my home drive to the backup one. Whenever I copy my documents folder I get up to 25 mbps. The music folder is slightly slower, but not too much. The pictures folder is the slowest and I've never gone above 5 mbps till now.
Tobi, I don't mean to question you, but I would be grateful if you could explain why this is so.

From a technical point of view I can't see an explanation for this. Which filesystem are your images stored on?

Both are ext4.

Edit
Strike that. I was mistaken Tobi, and I apologise for having spread misinformation. I remember now that this happened when I was copying the files in a much older system (6 yr old laptop) that has a pentium 4 processor. When I copy on my newer (but definitely only mid range dual core) system, I get much higher speeds. I got confused because I've been using the older system for a few weeks now and .......
I guess I don't have to say any more.