On 25 June 2015 at 09:15, Martin K. Petersen <martin.petersen@xxxxxxxxxx> wrote: > > The drive reporting deterministic zero is not enough. It needs to be > explicitly whitelisted before we report discard_zeroes_data=1. > Not sure what you mean here. I just meant I don't think the "lower limit" thing I am experiencing is related to the "type" of TRIM, at least not for any Deterministic TRIM. (Although I don't really know what exactly does Deterministic Read Data means. Perhaps it means vendor would make sure the LBA after TRIM reads either zero or a specific pattern of data?) > > I have several older drives that expect a single contiguous LBA > range. They don't handle multiple discontiguous ranges at all. > Well discontiguous is somewhat inaccurate here. I guess what you mean is they simply don't handle the next range until the previous one is used up. For example, "0:65528, 65528:65528" are definitely contiguous, but not fulfiling the requirement of your drives; while "0:65535 131072:65535" are definitely not contiguous, but your drives take them fine. By the way what are the consequences? Data loss? System hang? -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html