ldmwndletsm
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Not sure which forum to post this under? I hunted around, and there was only one, old post from 2014 (https://adsm.org/forum/index.php?threads/experience-with-logical-block-protection.28852/) where someone inquired about this parameter for the device class, but there was essentially no answer. There are a number of other posts where the term appears but only where its referenced in the configuration settings that the poster provided.
QUESTION: What is the difference between the LBProtect device class parameter and the built-in CRC and/or error checking already performed by LTO drives? What is this device class parameter giving you that the drive isn't already doing? Is anyone using this feature?
I know LTO drives perform error checks when writing data to the tape wherein its read back and validated. The type of CRC algorithm may depend on the LTO generation. I don't know about restoring data, and/or if the CRCs are stored on the tape or how the logical block protection works with LTO drives. I haven't looked at any of the nitty-gritty of the algorithms performed by these drives in any drive or SCSI documentation, and I haven't been able to find much in any online dicussions concerning this. We're using TSM 8.1.3 and LTO-6 tape drives.
Is it possibly the case that this feature is somehow enhanced over what the drives already do by default? Or maybe the drives have the ability to do a higher level of protection (than what they would otherwise do), but it has to be done via an application like TSM, assuming the drive supports it?
IBM has a document (http://www-01.ibm.com/support/docview.wss?uid=swg21568108) wherein they state that logical block protection is supported on the following drive types (as listed in the document), but that you must upgrade the firmware to a revision that has the logical block protection support, and that if using IBM drives that a particular IBM device drive version is required. It's still fuzzy, though, about what this device class parameter does if the drive already has the support? I guess I'm just confused?
QUESTION: What is the difference between the LBProtect device class parameter and the built-in CRC and/or error checking already performed by LTO drives? What is this device class parameter giving you that the drive isn't already doing? Is anyone using this feature?
I know LTO drives perform error checks when writing data to the tape wherein its read back and validated. The type of CRC algorithm may depend on the LTO generation. I don't know about restoring data, and/or if the CRCs are stored on the tape or how the logical block protection works with LTO drives. I haven't looked at any of the nitty-gritty of the algorithms performed by these drives in any drive or SCSI documentation, and I haven't been able to find much in any online dicussions concerning this. We're using TSM 8.1.3 and LTO-6 tape drives.
Is it possibly the case that this feature is somehow enhanced over what the drives already do by default? Or maybe the drives have the ability to do a higher level of protection (than what they would otherwise do), but it has to be done via an application like TSM, assuming the drive supports it?
IBM has a document (http://www-01.ibm.com/support/docview.wss?uid=swg21568108) wherein they state that logical block protection is supported on the following drive types (as listed in the document), but that you must upgrade the firmware to a revision that has the logical block protection support, and that if using IBM drives that a particular IBM device drive version is required. It's still fuzzy, though, about what this device class parameter does if the drive already has the support? I guess I'm just confused?