7 Beyond ZFS
In addition to ZFS, we have applied the same fault injec- tion framework used in Section 5 to a simpler filesystem, ext2. Our initial results indicate that ext2 is also vulner- able to memory corruptions. For example, corrupt data can be returned to the user or written to disk. When cer- tain fields of a VFS inode are corrupted, operations on that inode fail or the whole system crashes. If the inode is dirty, the corrupted fields of the VFS inode are propa- gated to the inode in the page cache and are then written to disk, making the corruptions permanent. Moreover, if the superblock in the page cache is corrupted and flushed to disk, it might result in an unmountable filesystem.
In summary, so far we have studied two extremes: ZFS, a complex filesystem with many techniques to maintain on-disk data integrity, and ext2, a simpler filesystem with few mechanisms to provide extra relia- bility. Both are vulnerable to memory corruptions. It seems that regardless of the complexity of the file sys- tem and the amount of machinery used to protect against disk corruptions, memory corruptions are still a problem.
ZFS needs ECC as much as every other file system.
ZFS requires an absurd amount of RAM dedicated to managing storage.
And ZFS needs ECC RAM, errors must be detected because with ZFS there can be a write to the hard drive to fix a mismatched "checksum" when the software is requesting a read. Bad RAM is a much bigger problem with ZFS than other file systems. Its really not a good idea for consumer hardware.
Disputed, to put it mildly.
Netcraft confirms, Microsoft is dying... um...
Ah! Netcraft confirms, Xenix is dying!
* Czechoslovakia (1993)
* East Germany (1990)
* Yugoslavia (1992)
And when a country enters the EU, and all contracts are now subject to new, overriding law which may negate these contracts?
Local backup (with per user snapshots) to a dedicated backup server, which has RAID, and snapshots the backups (the backup server has ZFS).
The backup server is itself backed up to the cloud.
Local mail gets its own server and an extra layer of backup.
Yes, I am paranoid. I only worry that I'm not paranoid enough.
The Apple MPW C compiler had a notorious set of error messages (does this count as an Easter egg?). http://www.netfunny.com/rhf/jo...
It's a minor problem, but as you do the rewrite, I'd appreciate it if you gave it a few milliseconds of thought
Waste not, get your budget cut next year.