Backing up recovery partition

[cyberfish]

My new laptop came with Vista, and a recovery partition. I'm going to wipe them out and install Linux. But I want to backup the recovery partition first, just in case I need it later to send it in for warranty services or something.

The recovery partition is ~10GB. I usually wouldn't mind having that sitting on my harddrive... but it's a 80GB SSD, and space is scarce.

Just to make sure, can I back it up using dd like this? (assuming the SSD is at /dev/sda, and the recovery partition /dev/sda1)

dd if=/dev/sda of=partition_table skip=446 count=64
dd if=/dev/sda1 of=recovery_partition bs=4M

According to Wikipedia, the partition table starts at 446 offset, and is 64 bytes long.
Master boot record - Wikipedia, the free encyclopedia

and to restore

dd if=partition_table seek=446 count=64
#reboot
dd if=recovery_partition of=/dev/sda1 bs=4M

Thanks

[MK27]

If your question is, can I use "dd" to copy an entire file system the answer is yes.

Probably you want to make sure the block size is the same but it looks like you are on top of that. Using an offset works too, I've used this to place a filesystem after a compressed kernel on a floppy, since the kernel can boot itself, then the kernel finds the filesystem using the offset.

You can compress the resulting file, etc too.

OH! And remember you want to keep a copy of the windows boot sector!

[cyberfish]

Ah yes, I have used dd for partition backup. But I'm unsure about the partition table part.

Is it necessarily to keep the Windows boot sector? I thought they are all the same and can be easily had by doing a repair from a Windows installation disk (I have a Vista disk).

EDIT: but true, I could also back it up while I am at it. It's just 446 bytes.

[MK27]

Originally Posted by cyberfish

EDIT: but true, I could also back it up while I am at it. It's just 446 bytes.

Hmmm, so it's contiguous with the partition table? I think when I have done this before I have just backed up a single chunk, probably 500 bytes, but I don't remember clearly...I definitely have put it back and had it work tho, but that was probably old copies of XP or Win 95.

[foxman]

Here's two way to save your primary partition table :

• with dd - save the whole MBR (simpler than just saving the partitions descriptors) with a command like "dd if=/dev/sda of=mbr.bin bs=512 count=1"
• with parted/fdisk - save your partition table information with a command like "parted /dev/sda unit s print > part-info.txt". With this information, you'll be able to recreate any of your original partition.

Also, I think most versions of dd consider a block size of 512 bytes by default; you should always specify it with the "bs=" option to be safe.

[Kennedy]

Originally Posted by MK27

Using an offset works too, I've used this to place a filesystem after a compressed kernel on a floppy, since the kernel can boot itself, then the kernel finds the filesystem using the offset.

Dude, you are showing your age here. . . This is no longer the case, and has not been the case for many years. I think that ended some time in the 1.34.x era, but I cannot recall.

[cyberfish]

Yeah, apparently the 512 bytes MBR is 446 bytes boot code + 64 bytes partition table + 2 bytes padding according to wikipedia.

[MK27]

Originally Posted by Kennedy

Dude, you are showing your age here. . . This is no longer the case, and has not been the case for many years. I think that ended some time in the 1.34.x era, but I cannot recall.

Well, I sure did it a few times with 2.1+ kernels. I have such a floppy in my closet somewhere, I could check it just to be sure but I believe there is no bootloader or anything, just a compressed kernel written with a pointer to the root device and the offset where the filesystem begins. Maybe there is a bootloader...hmmm. Much the same anyway, and you can certainly still do that (raw image is grub + fs w/ kernel), altho using floppies may be a too tight a squeeze