On Mon, 30 Jun 2014 18:21:06 Noah O'Donoghue wrote: > My current setup is a Ubuntu laptop, with 2 external drives. > > 1X 2TB ext4 for data storage > 1X 3TB ext4 for backup (using Crashplan commercial backup software). > > My question, is if I change the first drive to btrfs or ZFS, will I gain > resiliency from bitrot?
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). ZFS has one more copy of metadata than of data. If you have 1 copy of data (the default) then you have 2 copies of metadata. If you want protection against read errors or data corruption on a dingle disk with ZFS you can use the "copies=" option to use multiple copies. The number of copies of metadata blocks is 1 greater than the number of copies of data. The copies= option can be set on a per "filesystem" (where a ZFS "filesystem" is like a subdirectory on a traditional filesystem) basis. > My understanding is I need 2 drives in at least a RAID 1 to get automatic > healing from bitrot, No, "dup" for BTRFS metadata and "copies=" for data on ZFS give you this on a single disk. > but if I at least use a filesystem with check summing > support then I will be able to at least restore my affected files from my > Crashplan backups (which are compressed then checksummed and regularly > checked for errors automatically) and I won't have the risk of my main > drive corrupting my backups, because the read will FAIL if it doesn't pass > the checksum. Yes. -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/ _______________________________________________ luv-main mailing list [email protected] http://lists.luv.asn.au/listinfo/luv-main
