ein posted on Wed, 23 May 2018 10:03:52 +0200 as excerpted: >> IMHO the best course of action would be to disable checksumming for you >> vm files. >> >> > Do you mean '-o nodatasum' mount flag? Is it possible to disable > checksumming for singe file by setting some magical chattr? Google > thinks it's not possible to disable csums for a single file.
You can use nocow (-C), but of course that has other restrictions (like setting it on the files when they're zero-length, easiest done for existing data by setting it on the containing dir and copying files (no reflink) in) as well as the nocow effects, and nocow becomes cow1 after a snapshot (which locks the existing copy in place so changes written to a block /must/ be written elsewhere, thus the cow1, aka cow the first time written after the snapshot but retain the nocow for repeated writes between snapshots). But if you're disabling checksumming anyway, nocow's likely the way to go. -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
