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From: Szakacsits S. <sz...@si...> - 2003-04-09 15:36:40
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On Wed, 9 Apr 2003, Ian Jackson wrote: > > I do it as: > > ntfsimage -o - device | bzip2 ... > > That's much slower than simply using a format which encodes the > sparseness. Yes, I made some tests now also on an "average" box with "common" disk partition sizes. It's _desperately_ slow. bzip2 compresses sparse files extremely well but also extemely slow. Moreover it can't create sparse file. tar can but can't be stdin streamed from ntfsimage ... So I'm convinced. > I'm not saying sparse files aren't sometimes a useful technique. But > in the past, file formats which only make sense as sparse files have > turned out to be less useful because a smaller proportion of the > standard utilities work well on them. Yes, I thought the situation became a bit better in the last 8 years or so ... I was wrong :( > So I think that there is room for both facilities: the optimised image > copy, and the conversion to a stream representation. I like simplicity. Your way seems to be the winner. If restoreimage can create a sparse file of the original image [metadata] that't fine with me (needed for debug, test, development). Now this is fast, reliable and works. > > There is e2image in e2fsprogs, I don't know if it works with ext3 or not. > > Probably. > > I hadn't heard of that. As far as I can tell from its manpage it's > not quite the same thing as I think ntfsimage is or should be - but it > could benefit from being able to write a stream format. Yes. Actually apparently only XFS has such dump feature [what doesn't it have??? ok, undelete]. BTW, I strongly recommend, send your purposal for comments, review to the linux-fsdevel mailing list http://www.kernelnewbies.org/mailinglist.php3 > There's really no reason why ntfsimage shouldn't be able to do both. True. > I hope you'll accept my program which does write a stream format into > the linux-ntfs package. Anton's decision but I support it. My wishes are only - must have the consistency check. My experiences from ntfsresize feedbacks is that there are many corrupted NTFS out there. chkdsk fixed them nicely. In general no point and dangerous to backup a corrupted NTFS (unless it's for recovery). This can be taken from my version if you don't have [actually I'm planing to make it a library function]. - restoreimage should be able to create the image as a sparse file. I don't think this would be a big issue. - please also ask linux-fsdev. - bugfree :) BTW, apparently I won't have the possibility to send my version today but I'll do it ASAP. Cheers, Szaka |
