On 13/03/2020 12:37, Martin Simmons wrote: >> >> So it looks really there is really an issue on the drive 0 or the connection >> path. >> I will wait for the end of the both tests >> (btape on drive 1 and backup test on drive 0) > You could also try running the HP Library and Tape Tools: > > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbuy.hpe.com%2Fus%2Fen%2Fstorage%2Fstorage-software%2Fstorage-device-management-software%2Fstoreever-tape-device-management-software%2Fhpe-library-tape-tools%2Fp%2F406729&data=02%7C01%7C%7C79e8ed7ea00246e62b7a08d7c74bc22c%7C1faf88fea9984c5b93c9210a11d9a5c2%7C0%7C0%7C637197000502158967&sdata=yY%2FRzj%2FwZPVTcvvdxmc%2FgBgXxrBffiizD3IzFXI3xKs%3D&reserved=0
As someone who's faced this situation: LTT (and the IBM equivalent) won't help much for diagnosing a drive with a damaged head, or to see if the tape is actually full due to rewrites or to see if there are a batch of damaged tapes The last is important as a single damaged tape or head can cause cascade failures in both tapes and OTHER drive heads The undocumented parts of the diagnostic reports do give details of drive health for your support desk (You did purchase support with your LTO drive, didn't you?) - they're encoded and proprietary but contain health data for each of the 64-256 coils in each of the write and 2 read heads. LTO works by reading what's been written on the fly and _rewriting_ it if there are errors - the OP needs to read the cartridge MAM (chip memory) and see what it's reporting in terms of actual tape space usage and write retries, etc - a damaged drive or tape will manifest as showing 100% tape full whilst you get significantly less than the tape capacity written Without the correct tools - and knowing how to read th e results - you can't "See under the hood" to know what's actually happening. Assuming a recent OS and latest SG3 tools, the tape MAM can be read when the tape is in the drive using sg_read_attr Bear in mind there are a few proprietary differences between IBM/HP drive reports AND the author of sg3 utils hasn't incorporated all the work I did in interpreting results into the software (including the decoding of the actual tape manufacturer and batch numbers - they're there, but obfascated - this is important as there are only a few LTO tape makers and at least one manufacturer (Maxell) exited the business due to liabilities incurred from manufacturing defective product - it's not as simple as "avoid Maxell", because their product was rebranded by at least 5 other cartridge sellers including HP NB: There is NO fix for a bad head - the drive has to be replaced (if under support) or the head replaced (this costs about $600 for a LTO4 drive) AND ..... you can fix the head all you want, if there's a bad or damaged tape in your pool, it will trash the drive (and subsequent tapes) next time it's inserted - this is like the old Zip Drive "click of death". LTO is _extremely_ sensitive to dust - but there's "OK dust" - skin flakes and the like, or "BAD" dust - outside air dust (eg sand), plaster dust and printer toner. All of this dust is very fine - 2-10um in size and floats in the air. The stuff you can see is too large to float for long. However even 2um spans several tracks. The OK stuff just causes temporary errors and is usually flicked off the tape or embedded into the surface where it will only cause transient errors as that section of tape passes over the heads. The "bad" dust is abrasive, will destroy head coils and usually digs into the tape surface, to belt across the heads at every pass causing more damage each time. Bear in mind that a single 900 metre LTO4 tape has 211,000 metres of tape travel when writing from zero to 100% and you start to realise that's a lot of opportunities to wreck your drive. This happened to us - to the tune over over 1000 LTO4&5 tapes before we discovered what had happened. In our case we discovered that we had a casading problem caused by a bad batch (extremely abrasive) of HP tapes that were out of spec - HP replaced them, but that didn't repair our heads or mean that we were out of the woods, due to cross contamination. We ended up having to purchase a LTO tape cleaner (US$5000) AND a LTO MAM reader (US$1200) in order to be able to recover our data - and along the way we discovered that _new_ tapes sometimes have contamination on them too - only one supplier precleans their tapes The cleaner is a modified LTO drive fitted with a very large sapphire blade that the tape flies over - https://www.mptapes.com/cleaner/cleaner_lto.html The readers are sold by a number of resellers, but are made by MP Tapes and they have the best pricing: https://www.mptapes.com/veritape/index.html Some libraries (Quantum, etc ) have license extensions to collate and report tape+drive health on the fly - these cost about $1600 apiece Kern and I have discussed LTO return codes for some time - and there really needs to be a whole section on LTO in the documentation. For what it's worth - if you're backing up to any tape format other than LTO or IBM 3592, please stop doing so. Everything else is obsolete - Your drives and media are essentially unsupported/unrecoverable if anything goes wrong at hardware level(*) which means backing up to anything other than LTO/3592 is nothing more than 'a false sense of security' (*) Your data might be recoverable via specialists, but expect to pay thousands of dollars for the privilege and experience long delays getting it. _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
