Secondly, E01s natively support compression which typically results in a much smaller image file size. At face value, E01 seems to be the superior format. Think for a moment about a typical computer hard drive that might be subjected to computer forensics examination. Among other things, an examiner is likely to encounter two things: free space and compressible data high quality pictures, videos, etc. Now consider what is typically contained on a hard drive from a DVR.
First, there is usually little to no free space. In addition, the data recorded is heavily compressed with lossy technologies like H. Lossless compression the type used in E01, ZIP, and many other applications does a great job of offering the ability to save space while being able to recreate the original data exactly.
There are two issues, however. This will mean less performance. This particular hard drive was utilized in a real world DVR and was entirely allocated full. My goal is to read a specific portion of data off a raw disk device. Or do I need to use some other command to do it? If you know the length of the string you can do the reverse operation i. From: vladak via ibm-aix-l [mailto:ibm-aix-l Groups. So how do you read JUST a string? Sorry, let me clarify.
I want to write the string in a specific location on the raw disk and then begin a read off the disk from that same specific location.
I would also need to read for long enough to get me the full string I would also know how long the string is.
If the string is embedded a known offset into the disk, eg at sector 5 and each sector is b, use. Thanks for all the responses. Using rsync will ensure that the internal data in the destination filesystem is consistent. It will not ensure that the data in the files is consistent — to do that, you would need to lock the files and any programs that write to the files would need to respect these locks.
Show 4 more comments. Cadoiz 5 5 bronze badges. TimB TimB 1, 2 2 gold badges 14 14 silver badges 19 19 bronze badges. If you have a disk with bad sectors, you really should be using 'ddrescue' instead of dd. It's much more efficient, and has a much better chance of recovering more data. Consider this for discussion of the fastest bs settings: serverfault.
Add a comment. Community Bot 1. Kyle Cronin Kyle Cronin 1, 13 13 silver badges 26 26 bronze badges. You can actually also use a read-only mount. Props to the very few people who commented something about that. Show 7 more comments. Ben Williams Ben Williams 1 1 gold badge 7 7 silver badges 17 17 bronze badges. The first drawback can be resolved by gzipping the data as you make the copy. James Sumners James Sumners 3 3 gold badges 6 6 silver badges 17 17 bronze badges.
You already told the way to overcome the third drawback Enlarging a partition is generally a safe and fast operation versus shrinking or moving, which is slow and more dangerous since it's moving data around.
Tozz: You can improve the compressibility of a filesystem image by filling the filesystem with a file filled with 0's, syncing it to disk, then deleting it.
These are the basic and essential options for using dd to clone or rescue a disk. Sam Watkins Sam Watkins 3 3 silver badges 7 7 bronze badges. Actually it was mentioned before, in one answer and at least two comments. These options are essential for "recovery cloning", and it's no good having to search the comments for them.
The most popular answer is adequate if the disks have no bad blocks, e. Michael the example I gave is a command I have used several times for professional disk recovery. While there are other tools which might do a slightly better job, the example I gave is better at disk recovery cloning than every other dd example here, while also being suitable for cloning an error-free disk.
Therefore, I consider my answer to be the best here on how to "use DD for disk cloning". I did not add info on monitoring progress, compression, etc. This is not quite correct.
I'm guessing you don't want to dump a disk image to stdout. And throw in gzip on both ends to further minimize the sent data. Keep in mind that dd makes an exact copy , including all the blank space.
That means: 2nd drive must be at least as big as first If 2nd drive is larger, extra space will be wasted filesystem can be expanded mind you If the source drive is not full, dd will waste alot of time copying blank space.
You can copy either the entire drive, or a single partition this way. If this is a bootable drive, I'm pretty sure you need to install the bootloader after using dd Hope that is helpful. Brent Brent If you're cloning the whole hard disk, you're also cloning the boot loader. Assuming it's a onetime image it should mitigate this issue. This is kind of a cheap hack, but it's a quick and dirty way to monitor your DD process.
Tachyon Tachyon. I don't think this is very practical for a novice, they may be better served with the pv command. It's easier than the while loop and the OSX Learned this from en. Anders Hansson Anders Hansson 1 1 silver badge 4 4 bronze badges. Another grand feature is copying MBRs, partition tables and boot records.
Polish with fdisk after. You feel much more safe when you have your partition table backed up. Also, it makes migrating to another hard drive while changing partion structure a joy. Edward Groenendaal Edward Groenendaal 1 1 silver badge 6 6 bronze badges. I was referring to this page myself for different dd options when cloning disks, so it seemed a suitable place at the time to put the end result of what I used for cloning, especially since I thought it was rather neat myself : — Edward Groenendaal.
Sam Watkins 3 3 silver badges 7 7 bronze badges. The most info was described in previous inserted recipies, but not all was described. Znik Znik 1 1 gold badge 3 3 silver badges 12 12 bronze badges. Search DLL file. Order dll files by: version description language. MD5: a8bcee74c8. SHA 93b66a4f4fa8fdf70aed97ca8df5e MD5: 9d2e8ecdcd09cac4a66b23e0bc SHA dbb7e0f42ffa30d7d0feaff MD5: fa8b2fb94ce8e31a9ce6. SHA 5d1cb3d24da9fdaeb6daca9cedbd MD5: 74ee16bd8fdaa76a4bed SHA ce9aca70fbd1be8.
MD5: a3c0d59e3eeaad9aa2b2.
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