Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On 10/11/2017 11:30 PM, Eric Robinson wrote: > The TrimTester program consists of three parts. The main executable > (TrimTester) just writes loads of data to the drive and tests for file > corruption. My C++ consultant says, "It writes sequential numbers > wrapped at 256, spanning multiple files. It checks previously written > files, and if the file data is all zeroes, it is considered to be > corrupted." Are you referring to this program? https://github.com/algolia/trimtester/blob/master/trimtester.cpp One thing that I can tell you right away is that this program does not appear to be very trustworthy, because it may malfunction due to the use of incorrect datatypes for the purpose - apparently, it is attempting to memory-map quite large files (~ 70 GiB) and check using a byte-indexed offset declared as type 'unsigned', which is commonly only 32 bits wide, and therefore inadequate for the byte-wise indexing of anything that is larger than 4 GiB. While this indicates that the program might miss actual corruption, so far I have not found any definitive proof that the program will generate false positives (however, I did not check the program in much detail, judging by the overall quality I would not be surprised if it did), so we should still continue investigating. I would certainly recommend to double-check by running some other software to check for data corruption issues to ensure that the problem is not malfunctioning test software. br, -- Robert Altnoeder +43 1 817 82 92 0 robert.altnoeder at linbit.com LINBIT | Keeping The Digital World Running DRBD - Corosync - Pacemaker f / t / in / g+ DRBD® and LINBIT® are registered trademarks of LINBIT, Austria.