Hello Gurus,
Greetings.
I have been assigned some work on the development of a migration
tool. The requirement is that it has to migrate the data on a UFS/VxFs
filesystem to an ext2 filesystem.
What are the technical apects I will have to look into to achieve
the same? Is it possible to change the on-disk structure of the UFS/VxFs
filesystem to an ext2 filesystem? The question may sound weird but then
that is the requirement.
Kindly help me. Kindly send a cc of your mails to
srikanth.chowdary@tatainfotech.com as I have not subscribed to this list.
Thanks and Regards,
Srikanth
Hi, On Thu, Nov 14, 2002 at 03:13:31PM +0530, SRIKANTH CHOWDARY M. K. G wrote:> What are the technical apects I will have to look into to achieve > the same? Is it possible to change the on-disk structure of the UFS/VxFs > filesystem to an ext2 filesystem? The question may sound weird but then > that is the requirement.I'd get another disk and just copy the stuff over. There's some vxfs and ufs support in the kernel already, which may be enough for you to get readonly access to the data under Linux. --Stephen
Perhaps an ignorant question, but can I ask why are you selecting ext2 instead of a journalled solution? I would think that an fsck on several terabytes would take "a very long time". On Thu, 2002-11-14 at 08:48, Stephen C. Tweedie wrote:> Hi, > > On Thu, Nov 14, 2002 at 07:14:39PM +0530, SRIKANTH CHOWDARY M. K. G wrote: > > > Thanks a lot for ur patient replies. Sir, the problem is that the person > > does not want to spend time taking backing and then restoring on another > > disk. He wants some kind of a tool which will make the ondisk UFS/VXFS > > structure to that of an ext2 structure! > > > > Sir, if it is not feasible, I will have to give him strong reasons for > > the same. What are the practical difficulties in developing such a tool? > > You would spend longer writing and testing the tool than doing the > backup, reformat and restore. I mean, would you seriously considering > running an unproven format conversion tool on several TB of data > without a tape backup in any case? Given that you _need_ backups, > that sounds like the only sane way to go. > > --Stephen > > > > _______________________________________________ > Ext3-users mailing list > Ext3-users@redhat.com > https://listman.redhat.com/mailman/listinfo/ext3-users
Hi, On Thu, Nov 14, 2002 at 09:05:16AM -0500, Darrell Michaud wrote:> Perhaps an ignorant question, but can I ask why are you selecting ext2 > instead of a journalled solution? I would think that an fsck on several > terabytes would take "a very long time".Well, as far as the on-disk format conversion is concerned, ext2 and ext3 look exactly the same so converting to ext2 *is* converting to ext3 (modulo the trivial step of adding a journal inode.) --Stephen
On Nov 14, 2002 15:13 +0530, SRIKANTH CHOWDARY M. K. G wrote:> I have been assigned some work on the development of a migration > tool. The requirement is that it has to migrate the data on a UFS/VxFs > filesystem to an ext2 filesystem. > > What are the technical apects I will have to look into to achieve > the same? Is it possible to change the on-disk structure of the UFS/VxFs > filesystem to an ext2 filesystem? The question may sound weird but then > that is the requirement. > > Kindly help me. Kindly send a cc of your mails to > srikanth.chowdary@tatainfotech.com as I have not subscribed to this list.By far the easiest and most robust way of doing this sort of thing is to mount the existing filesystem under Linux, create a second filesystem with ext2/ext3 on it, and "tar cf - -C <old mnt> . | tar xvpf - -C <ext2 mnt>" This not only works very well, but also has the benefit of defragmenting your files and laying them out properly for ext2 instead of in-place conversion. Failing that, I would suggest looking at libext2fs and if there is a similar library for UFX/VxFs and seeing what can be done. I would be surprised if you could do any sort of reasonable in-place conversion because inodes and other data structure alignment will be different. Cheers, Andreas -- Andreas Dilger http://www-mddsp.enel.ucalgary.ca/People/adilger/ http://sourceforge.net/projects/ext2resize/
Hello Sir,
Thanx for the replies. Sir, I require the following details in
order to document the feasibility of porting the UFS/VxFs to ext2
filesystem.
UFS consists of cylinder groups.. EXT2 has block groups...
how can we co-relate or map these 2? can they be co-related?
While making the UFS filesystem, we specify the number of sectors per
track on the disk, number of tracks per cylinder on the disk, number of
disk cylinders per cylinder group, the rotational speed of the disk
in rps etc... whereas such data is not reqd in case of ext2.
The block sizes in case of ext2 is 1k,2k and 4k where as in UFS
it can be either 4K or 8K.
Sir, can such differences be mentioned to justify the difficulties in
porting UFS/VxFS to ext2? If yes... can you give me some more
pointers about the other differences ..
Kindly help.
Regards
Srikanth