[Please CC me, I'm not on the list.] Am Mo., 21. Okt. 2019 um 13:47 Uhr schrieb Austin S. Hemmelgarn <ahferroin7@xxxxxxxxx>: > I've [worked with fs clones] like this dozens of times on single-device volumes with exactly zero issues. Thank you, I have taken precautions, but it does seem to work fine. > There are actually two possible ways I can think of a buggy GPU driver causing this type of issue: [snip] Interesting and plausible, but ... > Your best option for mitigation [...] is to ensure that your hardware has an IOMMU [...] and ensure it's enabled in firmware. It has and it is. (The machine's been specced so GPU pass-through is an option, should it be required. I haven't gotten around to setting that up yet, haven't even gotten a second GPU, but I have laid the groundwork, the IOMMU is enabled and, as far as one can tell from logs and such, working.) > However, there's also the possibility that you may have hardware issues. Don't I know it ... The problem is, if there are hardware issues, that's the first I've seen of them, and while I didn't run torture tests, there was quite a lot of benchmarking when it was new. Needle in a haystack. Some memory testing can't hurt, I suppose. Any other ideas (for hardware testing)? Back on the topic of TRIM: I'm 99 % certain discard wasn't set on the mount (not by me, in any case), but I think Mint runs fstrim periodically by default. Just to be sure, should any form of TRIM be disabled? The only other idea I've got is Timeshift's hourly snapshots. (How) would btrfs deal with a crash during snapshot creation? In other news, I've still not quite given up, mainly because the fs doesn't look all that broken. The output of btrfs inspect-internal dump-tree (incl. options), for instance, looks like gibberish to me of course, but it looks sane, doesn't spew warnings, doesn't error out or crash. Also plain btrfs check --init-extent-tree errored out, same with -s0, but with -s1 it's now chugging along. (BTW, is there a hierarchy among the super block slots, a best or newest one?) Will keep you posted. Cheers, C.
