On 30/06/14 23:24, Russell Coker wrote: > On Mon, 30 Jun 2014 22:28:52 Anthony Shipman wrote: >> On Mon, 30 Jun 2014 08:12:45 pm Russell Coker wrote: >>> BTRFS in a default configuration will use "dup" for metadata. So a bad >>> metadatablock can be corrected. But a bad data block causes data loss - >>> >>> at least you know you have data loss (as opposed to silent data >>> corruption on older filesystems). >> >> What does data loss look like? Does the whole file become unavailable or >> are there just error codes delivered along with the data? > > If only data blocks are corrupted and you read from a part of the file that > doesn't contain those blocks then the kernel won't know that some other part > of the file is corrupted. So it's possible to get some data back from a > corrupted file. >
You can "easily" recover the rest of the data on any file system if you are prepared to go low level unless the sector in question is a hard write error, and even then I think it will work if the drive's firmware does a bad sector remap. Use dd with the noerror flag to read the physical sector (I have had a case where a one of the eight logical sectors was dud) then write it back, and hey presto the file can be read. Actually in the case above it was in a fat32 partition directory block and we got a lot of files back. Glory to bootable linux sticks. _______________________________________________ luv-main mailing list [email protected] http://lists.luv.asn.au/listinfo/luv-main
