> > To check my understanding - would it be correct to say that; > > 1. Using dd to copy the first 512 bytes (MBR) is ALL that is needed to > > setup the partitions - that is i wont need to run fdisk etc afterward. > > This is correct if you only have primary partitions. It will not copy the > extended partition and any logical partitions in it. They reside in the > first > sector of the extended partition, which is not a boot sector, but contains > the > logical partition table. (I found this out the hard way!) > > Have a look at this to see how you can back up the extended partition > tables > with sfdisk (there's more than one of these, if you have more than one > logical > partition) : > > http://www.partimage.org/Partimage-manual_Backup-partition-table > > > > 2. Using dd in this way of course will not update the kernel's knowledge > of > > the partition table so a partprobe is necessary > > Yes, or a reboot. > > > > 3. When using fdisk to write a partition table and exit, it calls a > re-read > > of the partition table by the kernel so any changes should be ready > > straight away. (there's a message about calling ioctl when it exits - so > i > > guess that is the update) > > They are ready (i.e. written) but not yet read by the OS. Tools like > gparted > (part)probe the device to re-read the partition table after saving changes > to > disk. >
Thanks Mick. Great info, esp about the extended partitions. Fortunately, I dont have any on this disk but good to know.
