oslomike Posted September 26, 2012 Report Share Posted September 26, 2012 I have a SAN strage system (shared storage over iSCSI) and sometimes I need to copy a bunch of Gigs from one disk to another so that I can do some maintenance on the drive partitions. Retrospect sees all disks and has them mounted and they all get backed up with a script that runs at night. Sometimes, and I don't know why or how, Retrospect will go and backup again all the files I just copied, even though they are already backed up. Retrospect is treating them as if they were modified or something. What is happening to these files that makes Retrospect back them up AGAIN?! Are there any guidelines regarding permissions for disks? Do the permissions have to be set on each individual computer that accesses the files? I have been struggling with this for some time, and I still don't have a straight answer. Anyone? Thanks! mike 1 Quote Link to comment Share on other sites More sharing options...
Lennart_T Posted September 27, 2012 Report Share Posted September 27, 2012 It isn't clear what you are doing. When you write "backup", do you really mean a "backup" in Retrospect's parlance and not a "duplicate"? (By context, I guess it's a "duplicate".) When you write "Sometimes, and I don't know why or how, Retrospect will go and backup again all the files I just copied", do you mean it starts a backup/duplicate all by itself or have you set up schedule or start it manually? Yes, Retrospect looks at a file's metadata to see if it has changed. So if one volume has "ignore ownership" turned on but not the other, there would be a difference and Retrospect will copy the files again. Retrospect also looks at ACLs. This might help: http://support.apple.com/kb/HT2963 Quote Link to comment Share on other sites More sharing options...
oslomike Posted September 27, 2012 Author Report Share Posted September 27, 2012 HI Lennart, I mean a straight finder copy from one disk to another. When I say backup, I mean a Retrospect script that scans a disk with newly copied files that it has already backed up (that were previously on a different disk-same files though). Is it best to have ignore disk permissionsn checked "off" for all disks? OR checked "on"? Thanks, Mike Quote Link to comment Share on other sites More sharing options...
oslomike Posted September 27, 2012 Author Report Share Posted September 27, 2012 Also, What consequences does it have if a disk is set to have ignore ownership "on" and then gets turned off later. Will all files already written get changed when turning it "off" again? mike Quote Link to comment Share on other sites More sharing options...
Lennart_T Posted September 27, 2012 Report Share Posted September 27, 2012 A Finder copy does not (fully) copy the file metadata. So Retrospect sees the metadata as changed and copies the files again. I have ignore ownership "on" for my external disks that doesn't contain any OS. But my storage isn't shared between users. So I don't know the answer to your question. It seems as "ignore ownership" would be a bad thing for shared storage. "Who owns this file?". You can't really tell, can you? Quote Link to comment Share on other sites More sharing options...
oslomike Posted September 27, 2012 Author Report Share Posted September 27, 2012 I did a little testing. I found out something interesting that maybe be of use to others. When doing a finder copy from two different disks on the SAN (one mac with two disks of the SAN mounted), if the "ignore ownership" is ON for both of the disks being used for reading and writing, then Retrospect will see the copied files as modified and back them up again. If I turn OFF "ignore ownership" on those two drives and do the finder copy again, then Retrospect does not see them as modified and thus they do not get backed up again when asked to. I also found out that for every client of the SAN, the disks permissions are different! My thinking is to go to every machine that has access to the SAN disks, and make sure that every SAN disk has the "ignore ownership" turned off. At least I want to try this for a while and see if I have any unnecessary files getting backed up. Does this seem to make sense for how the ownership rules work with Retrospect? Mike Quote Link to comment Share on other sites More sharing options...
oslomike Posted September 28, 2012 Author Report Share Posted September 28, 2012 Hold everything. Now I'm not so sure. Strange behavior with copying and Retrospect. I can't say that there is any rule at all with copying and shared storage. I'm confused. I guess I will have to test some more. mike Quote Link to comment Share on other sites More sharing options...
Lennart_T Posted September 28, 2012 Report Share Posted September 28, 2012 There are two apps created for copying files from one volume to another: Carbon Copy Cloner SuperDuper! Both work just fine. Both are free with limited features (such as copying an entire volume to another). All features unlocked for a small amount (such as scheduling and "smart" copy that copies only changed files). Quote Link to comment Share on other sites More sharing options...
oslomike Posted September 28, 2012 Author Report Share Posted September 28, 2012 thanks lennart! Does this mean that the files will appear to Retrospect as the same and no need to back them up again after being copied? Does the ignore ownership matter whether it's on or off to use these programs? Quote Link to comment Share on other sites More sharing options...
Lennart_T Posted September 28, 2012 Report Share Posted September 28, 2012 I can't tell since I never tried these apps together with Retrospect, and never with ignore ownership checked/enabled. I use them to make bootable clones of system disks. Quote Link to comment Share on other sites More sharing options...
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