5 ms·
It only takes one bit wrong to fuck your file system.
by cjsuk 9y ago
It only takes one bit wrong to fuck your file system.
- thomastjeffery 9y agoYou make it sound like filesystems are so vulnerable. They aren't. The chances of memory failure ruining data are extremely slim; lower than for hardware failure. If you care about your data, back it up.
- burntwater 9y agoBackups don't do anything if the original material contains the flipped bits.
- cjsuk 9y agoI ran a lab notebook in word for a number of years and the document got fried by a filesystem error. The backup was toasted as well. This was corruption which broke the stage machine or parser in word which acted as a damage amplification. As for the source of the error, we can only speculate but the possibility of a flipped bit is higher than you think. Try running memtest86 on a PC without ECC for a week. You will be surprised at the results. I’ve seen perhaps 3 or 4 failures of this in new hardware. DRAM is not perfect.
- pbalau 9y agoIn 20+ years that bit eluded me...
- leonroy 9y agoFrom what I understand (very roughly) with ZFS or BTRFS at least it takes one flipped bit in the particular block of memory which has just been successfully checksummed and 'approved' by the filesystem as valid for a write operation. Those are quite a few hoops to jump through so let's not head towards melodrama just yet.
- cjsuk 9y agoThat’s fine but most of us are running on NTFS, HFS+ or ext4 where it matters. And then there’s the same problem with MLC SSDs which are just arrays of capacitors encoding that state as different charge potentials. As a former EE, capacitors leak regardless of implementation.