Hi Andreas, I remember, that the bareos packages I installed from the official FreeBSD ports came with a note saying, that I should change some default settings or else the tape positioning would not work correctly. Two EOF was one of them. Among others I also set the minimum block size because I experimented with different dynamic block sizes in order to get to a solution. However for the latest tests I kept the config file minimalistic and kept the values mostly default.
Thanks for the tip with the tapealert flags. Either there is nothing wrong with the tape drive or it does not emit TapeAlerts. I tried capturing them with tapeinfo and with smartctl. None produced any valuable output. I also tested again with tar. This time I also checked the file integrity before writing to tape and after restoring from tape with SHA256 checksums. I've had several errors which led to the checksums not being identical. But what's weird is that most of the files that I restored from tape are fine while a few are not. And it is always the same files which are corrupt. I also used a brand new tape again and I tried everything using a LTO-Tape from a previous generation (LTO-3 Tape in a LTO-4 drive), but with the same results. One thing that I came across is that when I set my tape drive to fixed block size (e.g. 131072 bytes) with mt, I can successfully write and restore files with tar. I tried setting the Minimum, the Maximum and the Label Block Size in Bareos to the same value that the tape drive is set to and at first it seemed to improve things. However when I run a restore or a verify job, I get an "End of Volume" error when the drive is forward spacing to the wanted block. I must admit, I am running out of ideas what could be the problem. I still have my old LTO3 tape drive lying around and I am willing to test everything with that, because I am getting the feeling, that my LTO4 drive is not working properly, which would be a shame, because I just bought it. If you have any other idea, which does not involve ripping my hardware apart, let me know. I am very grateful for any input you can provide. Thanks again and happy christmas days! Andreas Rogge schrieb am Montag, 19. Dezember 2022 um 14:31:35 UTC+1: > Hi Benedict, > > looking at your configuration there are two parameters where I don't > unterstand why you set them. > Do you have any special requirement for "Two EOF"? Usually that > parameter is not needed. > Why did you set Minimum Block size to 64k? The default is 63k and > usually there is no need to configure this at all. > > If it doesn't break with files and only happens after you have written > some amount of data to the tape, I would suggest that we first make sure > your tape drive works correctly. > Especially "it works until i back up more than 900 MiB" sounds like your > tape drive might have an issue. > > Did you check for tapealert flags? If I'm not mistaken on FreeBSD this > should be doable with "smartctl -H". Maybe your drive reported problems > that you didn't realize yet. > Did you look at the kernel log if there is anything related to your > tape-drive? > > When you tested with tar, did you make sure the restored data was > correct? The checksums in tar only protect the headers, not the data. So > if there is a bit-flip in the data, tar won't notice that, but just > restore bogus data. > > Best Regards, > Andreas > > -- > Andreas Rogge [email protected] > Bareos GmbH & Co. KG Phone: +49 221-630693-86 <+49%20221%2063069386> > http://www.bareos.com > > Sitz der Gesellschaft: Köln | Amtsgericht Köln: HRA 29646 > Komplementär: Bareos Verwaltungs-GmbH > Geschäftsführer: S. Dühr, M. Außendorf, J. Steffens, Philipp Storz > -- You received this message because you are subscribed to the Google Groups "bareos-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/bareos-users/59c348bb-1958-4789-9059-1269222d4d95n%40googlegroups.com.
