--On Dienstag, 5. Dezember 2006 13:37 +0100 Rudolf Cejka <[EMAIL PROTECTED]> wrote: >> With technology like LTO-3, perhaps it is time >> to consider giving the user the ability to turn >> off the CRC32 generation and comparison.
Agreed. LTO verifies the written data on the fly. No need for verifying or CRCs for bacula here. I'm not so shure about the bus inbetween though... What if data gets corrupted say on the SCSI bus/controller/whatever. Is consistency guaranteed by the SCSI protocol? And what about the fd<->sd path? Is there an additional checksum protecting the data going over the network (despite of TCP)? > It would be very good thing. I tried to patch Bacula personally, > but then I was afraid to use it in my real environment, until it is > tested and until I'm sure I can restore the data too :o) The patches > were not finished and maybe they are lost. I decided that I'm not > sufficiently ready to do such a low level thing. I have read about > LTO3, that "the tapes contain a strong error correction algorithm that > makes data recovery possible when lost data is within one track or up > to 32 mm of the tape medium." Another interesting thing is that LTO3 > tape drive uses flying tape over the heads (like in hard drives) as much > as possible, so cleaning tapes are almost not used in effect. HP says > that the drive can run up to 6 000 hours without cleaning tape use (where > just small internal brush is sufficient), which was big surprise for me. > Unfortunatelly I have got this information after I have bought 5 cleaning > tapes :o) Imagine, that one cleaning tape may be exhausted even up to > after 90 000 hours = 3750 days >= 10 years... :o) Actually cleaning is even harmful to the drive's heads. You should _never_ clean an LTO drive unless it requests a cleaning tape, as indicated by front LED, Tape Alert or whatever. We use a LTO1 drive and only backup about 100 GB a week. The drive is in service for over one year now and never needed to be cleaned so far. Regards, Georg ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
