On 24 Nov 2020, Wols Lists told this: > On 24/11/20 07:20, Mukund Sivaraman wrote: >> * With RAID-6 with write-intent bitmap in use, ext4 in ordered mode, no >> disk failures, and abrupt power loss, is there any chance of data loss >> in files other than those being written to just before the power loss? > > Probably. Sod's law, you will have other files on the same stripe and > things could go wrong ... Plus I believe some file systems (including > ext4?) store small files in the directory, not as their own i-node, so ext4 can store small files in the *inode*, not in the containing directory: that's impossible, since an inode can appear in many directories at the same time. ... but, of course, inodes on many filesystems are packed into big tables of inodes, and if you have a write hole hitting an inode write, you've probably buggered up a bunch of other inodes too. And inodes are more or less unordered, so that's just smashed a random spray of things on the disk... it is quite posible that a lot of them are in directories close in space or in time-of-write to the one you were updating, but not necessarily. Reach for backups time. > RULE 0: RAID IS NO SUBSTITUTE FOR BACKUPS. But backups are a substitute for lack of sleep (for me anyway, because if I don't have good backups, I can't sodding sleep).
