Might these be the source of the problem, or could it be something else? The only variables that I can think of that I've not checked are my Ethernet cables and my router. Needless to say, in these circumstances, Retrospect isn't providing me with a backup that I can rely upon. I still get what I consider to be an inordinate number of "miscompare" errors. So it seems that with this set of files it makes no difference which drive is being used. With this different set of files, I got about 50-60 "miscompare" errors in both cases, all involving files that are static and do not change.
#Verify lacie backup mac windows#
Third, to check this out I did a backup of a different set of files from the Windows machine to both the La Cie and Hammer drives using USB 2.0 with both drives. So this suggests that perhaps the problem is with the La Cie Big Disk. Second, I confirmed that the backup of these same files to an external Hammer drive using USB 2.0 had no "miscompare" errors at all. So this test ought to eliminate my FW800 port and cable as the source of the problem. Also, the files that miscompare are different from one backup to the other. And again, these are not files that change they are static. 195), but this is still an unacceptable amount. I got 1/3 as many "miscompare" errors as before (62 v. OK guys, I did a lot of testing and the results aren't very encouraging.įirst, I redid the 60 GB backup I first posted about to the external LaCie Big Disk using a USB 2.0 connection instead of FW 800. Note that this does NOT solve the problem of inconsistent database backups on a live server (discussed extensively elsewhere in these forums), and still makes it necessary to shut some services down temporarily during the backup. I've made a feature request a few times, about a year or so ago.
It even allows you to re-validate the integrity of the backup at any time in the future, even if the original source file is unavailable. This is how, for example, BRU (Retrospect's competitor, from Tolis Group) does it, and I wish Retrospect handled things this same way because it would give you confidence that the files were backed up correctly even if the source file on disk has changed in the interim. An alternative way to handle this would be to compute a polynomial checksum (MD5, whatever) for each backed-up file and then, rather than doing a verify comparison with the file on disk, re-compute the polynomial checksum for the backed-up file when read from the backup medium, compare with the recorded polynomial checksum saved when the backup was made.
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With the present design of Retrospect Mac (backup pass followed by verify comparison pass), it takes judgment to look at each of the log error entries to decide whether there is a problem. The only thing that the error message means is that the file backed up on the destination is not the same as the source file now on the disk at the time of the subsequent verify pass. This is normal and does not necessarily indicate any hardware problems at all. And, because Unix (Mac OS X) is a modern operating system, there are always things going on in the background (syslogd, etc.) that cause log files, ec., to change. The same can happen if you are backing up a networked client while it is being used. If, for example, you are backing up a live server, it can simply indicate that data is changing while the backup is going on. Twickland, I respectfully and vigorously disagree. If you recently updated, you might want to try reverting the system to an earlier version and see if that makes a difference. Also, some users were reporting FW issues with 10.4.7. If you have access to another computer, you could try backing up using its FW port as a point of comparison.
#Verify lacie backup mac software#
(Retrospect stresses the drive more than a lot of other software and will therefore sometimes flags drive problems earlier.) We had problems with Retrospect and our LaCie 500 drive that LaCie blamed on Retrospect, until a couple of weeks later when the drive spontaneously began reporting itself as having two volumes, one 250 GB and the other 2TB.Īs for FireWire, the cable is easy to check by swapping, though it's probably least likely to be the source of trouble. Try running a disk utility such as DiskWarrior, though a clean bill of health doesn't necessarily exonerate the drive. I'd suspect a problem with the LaCie drive, or possibly with your FireWire adapter or cable. While they can be benign (such as when a file on the source volume is modified by a running application between the time of backup and compare), given your symptoms, it sounds like trouble with the backup set. errors are always a concern, because they mean that the source volume and destination backup set are not identical.