backup hard disk with dd- time estimates

kpachopoulos · 05-13-2007, 07:13 PM

Hi,
i am dd'ing data -offline- from an 80GB internal hard disk to a USB-external hard disk of exactly the same type. The process has been running now for about 3 hours. I once remember dd'ing data to a 256MB compact-flash, which took me about 10 minutes. If the relation of data and time is analogous, i could be copying for a couple of days! Can somebody share his experience? I haven't found anything useful in the net so far...

Thanks

stress_junkie · 05-13-2007, 08:04 PM

I've used dd for partitions in the 60Gb range. The 60GB takes about 90 minutes going from an internal IDE hard drive to a USB external hard drive. How much RAM do you have? I have 1 GB. See if your computer is using a lot of swap space. If it is then you might improve performance by increasing the swap space available or adding RAM.

Junior Hacker · 05-13-2007, 09:33 PM

As mentioned above, it all hinges on the available horse power (ram, ram type, cpu clock speed, etc.) Three hours is not unrealistic for many mainstream systems.

syg00 · 05-13-2007, 09:56 PM

I'd be more concerned with *which* USB protocol you are using - better hope it's USB2.
Doesn't sound like it though - 256Meg in 10 mins sounds like a (bad) USB1.1 transfer.
And I think "a couple of days" estimate is a bit on the low side if true.

alexhonig · 12-13-2011, 09:10 AM

Quote:

Originally Posted by nocturna_gr

Hi,i am dd'ing data -offline- from an 80GB internal hard disk to a USB-external hard disk of exactly the same type. The process has been running now for about 3 hours. I once remember dd'ing data to a 256MB compact-flash, which took me about 10 minutes. If the relation of data and time is analogous, i could be copying for a couple of days! Can somebody share his experience? I haven't found anything useful in the net so far...

I know this post it's very old, but i wanna help.

To estimate dd'ing data, i made the following:

execute de dd command for 5 seconds and cancell it. Now you should get the time per seconds, and in base of that you can calculate without problems

So, I have 28G of harddrive, and the time after execute the command was 3.6 M/s

And I have 28*1024 = 28672 MB
28672 MB
-------- = 7964,444444 seconds = 132,7407407 Minutes = 2,212345679 hours.
3.6 MB/s

hope it helps.

Thanks

fadfa

---------- Post added 12-13-11 at 01:11 PM ----------

Quote:

Originally Posted by nocturna_gr

Hi,
i am dd'ing data -offline- from an 80GB internal hard disk to a USB-external hard disk of exactly the same type. The process has been running now for about 3 hours. I once remember dd'ing data to a 256MB compact-flash, which took me about 10 minutes. If the relation of data and time is analogous, i could be copying for a couple of days! Can somebody share his experience? I haven't found anything useful in the net so far...

Thanks

i am dd'ing data -offline- from an 80GB internal hard disk to a USB-external hard disk of exactly the same type. The process has been running now for about 3 hours. I once remember dd'ing data to a 256MB compact-flash, which took me about 10 minutes. If the relation of data and time is analogous, i could be copying for a couple of days! Can somebody share his experience? I haven't found anything useful in the net so far...

I know this post it's very old, but i wanna help.

To estimate dd'ing data, i made the following:

execute de dd command for 5 seconds and cancell it. Now you should get the time per seconds, and in base of that you can calculate without problems

So, I have 28G of harddrive, and the time after execute the command was 3.6 M/s

And I have 28*1024 = 28672 MB
28672 MB
-------- = 7964,444444 seconds = 132,7407407 Minutes = 2,212345679 hours.
3.6 MB/s

hope it helps.