2015-08-08 21:05 GMT+02:00 Hugo Mills <h...@carfax.org.uk>: >> Maybe someone can give some clues why does this happen in the first >> place? Is it unfortunate timing due to the abrupt power cycle? >> Shouldn't CoW protect against this somewhat? > > Not "somewhat": it should protect it completely. There are two ways > that this can happen: it's a bug in btrfs, or there's something > stopping barriers from working. That latter case can be either a bug > in the kernel's block layer (pretty unlikely), or the hardware is > behaving badly and ignoring the barriers (more likely, particularly if > it's on a USB/SATA converter).
Thanks for the information. The setup is nothing out of the ordinary. The disks are HGST HUS724040ALA640 running on a Dell H310 SATA controller and configured as JBOD. It's all running on defaults on a Dell PowerEdge R720. SMART says the disk write cache is enabled - maybe that's part of the problem? > I don't think there's a good solution to transid failures, I'm > afraid. The best that I'm aware of is to use btrfs restore to grab the > pieces of your FS that aren't up to date in your backups, and then > restore from them. Okay, fortunately can I dismiss the data - or is the broken Image of any use for anyone? It's a 4TB disk but I guess I could create a compressed (partial) image if it's of interest to anyone. regards Martin -- 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
