(no subject)
Hi, I am using rsync between two pc's. when i am rsync throught the ethernet their is no problem. But between the same pc if i am doing a rsync with a dialup line, i am getting an error error message in /var/log/rsync.log is reverse name lookup failed forward name lookup failed Can anybody tell why the problem is coming Thanks in advance, - hari -- To unsubscribe or change options: http://lists.samba.org/mailman/listinfo/rsync Before posting, read: http://www.tuxedo.org/~esr/faqs/smart-questions.html
RE: Incremental backups and batch mode.
Diego wrote: > Right, wonderful, but let's consider a big database file, let's say > a 2Gbyte file, that is slightly changed every day of about a 10% ... > So at every backup the whole 2Gbyte file is saved. ... > So I would like to use the rsync algorithm to calculate the differences > (delta files) for the levels n>0 in the same order dump and tar work > but saving much more tape space. Ah... now I see. Unfortunately, this one's over my head. Can anyone else help here? Can rsync deal explicitly with parts of files? Mike -- To unsubscribe or change options: http://lists.samba.org/mailman/listinfo/rsync Before posting, read: http://www.tuxedo.org/~esr/faqs/smart-questions.html
RE: Incremental backups and batch mode.
Thanks, now I know how rsync backup option works. But I haven't been so clear about what I would like to do. >> I would like to have a first snapshot (level 0) that is a complete copy, >> and then other incremental backups that are just delta files >> (just the differences from the level 0 snapshot). > >The "normal" utilities for this job would be dump and tar, especially if >you're dumping to tape. You can also use rsync, but it's somewhat >indirect if you're dumping to tape! :) Right, wonderful, but let's consider a big database file, let's say a 2Gbyte file, that is slightly changed every day of about a 10% With those tools, the nex level backup consists in checking the modification time of the files, if the files are changed since last backup, they are saved again. So at every backup the whole 2Gbyte file is saved. If the backup is needed twice a day, in a week 28Gbytes are used, even if the changed parts are about one tenth. So I would like to use the rsync algorithm to calculate the differences (delta files) for the levels n>0 in the same order dump and tar work but saving much more tape space. I hope to be a bit clearer now... Diego Liziero -- To unsubscribe or change options: http://lists.samba.org/mailman/listinfo/rsync Before posting, read: http://www.tuxedo.org/~esr/faqs/smart-questions.html
RE: Incremental backups and batch mode.
> Something similar: > I would like to have a first snapshot (level 0) that is a complete copy, > and then other incremental backups that are just delta files > (just the differences from the level 0 snapshot). The "normal" utilities for this job would be dump and tar, especially if you're dumping to tape. You can also use rsync, but it's somewhat indirect if you're dumping to tape! :) > That should be done saving the checksums of the level 0 backup locally > and then checking the current files against those checksums to calculate the > delta files to be saved as leve 1 backup, and so on. Okay, one thing that takes a little getting used to here is that if you use rsync, the backup order is reversed. Let's see if I can explain it here. Using dump or tar, the 0 backup is large; it contains the whole filesystem at the time it was made. Then the 1 backup is smaller; it contains only the changes made between t_0 and t_1. The 2 backup would also be small, consisting only of changes between t_1 and t_2. And so on. Using rsync, the process is reversed. The *most recent* backup is the big one, and *earlier* backups contain only the files that changed. So the 0 backup is the most recent one, the 1 backup contains only those files that changed between t_1 and the most recent backup; the 2 backup contains only those files that changed between t_2 and t_1, and so on back in time. It's counterintuitive, but it's vastly more efficient for remote backups since you only need to do a full dump once, then never again. Now, how would you implement it? For simplicity's sake, I'm going to say that you're backing up /home into the directory /home-backup. Extending that to backup on a remote machine is a separate (albeit easy) issue, so I won't cover that here. Under /home-backup, you make folders like so (you'll probably find your own names for these folders): /home-backup/current/ /home-backup/current-1day/ /home-backup/current-2day/ The idea is that current/ would contain the current image (most of the files), current-1day/ would contain only the files that changed since yesterday, and current-2day/ would have anything that changed between two days ago and yesterday. You can have as many of these as you want, and they don't have to be evenly spaced; this is just for example. Now, to make it work, run something like this once a day: # delete the oldest incremental backup rm -rf /home-backup/current-2day # shift the intermediate incremental backups back by one mv /home-backup/current-1day /home-backup/current-2day # rsync into /home-backup/current, copying any changed files into the # folder current-1day first rsync -vab --delete --backup-dir=/home-backup/current-1day /home/ \ /home-backup/current You can also use exclude lists and all that other stuff. Is this clear? Mike -- To unsubscribe or change options: http://lists.samba.org/mailman/listinfo/rsync Before posting, read: http://www.tuxedo.org/~esr/faqs/smart-questions.html
Incremental backups and batch mode.
I'm trying to use the rsync algorithm for incremental backups. After a quick look at rsync I saw the batch mode operations, and I thought that maybe I can modify them for incremental backups. What is needed is to add an option to save the checksums of all the files of the level 0 backup and a second option to use the level n checksum to calculate the delta batch files for the level n+1 backup. After a deeper look into the batch mode I saw that it is too specific to that kind of application for which it has been written. The contents of the *.rsync_csums files seem to be always 1 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 3 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 5 ... instead of the real checksums. I think that the batch mode would be more useful (at least for the incremental backup) if it worked like rdiff: an option to save checksum, one to calculate and save the deltas using the previous saved checksums and the current files and one third option to read the delta files and update the old files. As regards the incremental backup program I would like to write, I don't know if it is worth modifying rsync or instead starting to write something new based on librsync. Any suggestion? Thanks for any help. Diego Liziero. (Please, cc you answer to me as I'm not subscribed to this mailing list) -- To unsubscribe or change options: http://lists.samba.org/mailman/listinfo/rsync Before posting, read: http://www.tuxedo.org/~esr/faqs/smart-questions.html
rsync raising an IO error for an excluded file
Hi,
when syncing from windows NT/cygwin to linux usimg rsync 2.5.2 I get the following
error:
readlink pagefile.sys: Permission denied
IO error encountered - skipping file deletion
pagefile.sys is however in the exclude-list, so I think rsync shouldn't care that it
can't stat the file.
The code fragment responsible is
if (readlink_stat(fname, &st, linkbuf) != 0) {
int save_errno = errno;
if ((errno == ENOENT) && copy_links && !noexcludes) {
/* symlink pointing nowhere, see if excluded */
memset((char *) &st, 0, sizeof(st));
if (check_exclude_file(f, fname, &st)) {
/* file is excluded anyway, ignore silently */
return NULL;
}
}
io_error = 1;
rprintf(FERROR, "readlink %s: %s\n",
fname, strerror(save_errno));
return NULL;
}
Shouldn't/couldn't the "ignore silently if excluded" be specified less strictly to
cover the above "permission denied" error as well?
Thanks, Martin
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