On Tue, Jul 29, 2008 at 12:41:25AM +0530, Vineet Agarwal wrote: > yeah i meant that we have to separate filesystems, > stored for example on /dev/hda1 and /dev/hda2, and we want to combine > the data in the two filesystems into a single filesystem /dev/hda3, or > combining the contents of /dev/hda2 so that it is also in /dev/hda1 > > so is there any mechanism exist to do so either online or offline . please help There is no direct way to do this. How big are the filesystems involved? The standard and easist way to do this would be to copy /dev/hda2 to another device, then if /dev/hda1 was created with on-line resizing inode, expanding /dev/hda1 to fill the space taken by /dev/hda2, and then simply use "cp" to copy the contents that had previously been in /dev/hda2 into the filesystem on /dev/hda1. In theory it would be possible to write a program would take to adjacent filesystems, and map out where the blocks would be once the two partitions were combined, and then relocate blocks to make a single filesystem. No one has done such a thing, however, for any filesytem. It is definitely not a trivial thing to do, but it is not impossible; it's not that different from some of what an off-line resize2fs operations does, albeit maybe 3-4 times more complex. The main thing is that no one has ever taken the time to do such a thing, because except for truly large filesystems, it's cheaper just to get an extra disk drive, and just copy the contents off, and then recreate the filesystem. - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
