SnapRAID is only one of the available not standard RAID solutions for disk arrays. The best known others are: • - Commercial and OpenSource GPL2 solution. A modified version of the Linux Reiserfs filesystem with real-time redundancy. No integrity checksum is supported. • - Commercial and proprietary C++/Java application for Windows, with some limited support for Linux. It supports both snapshot redundancy and real-time redundancy, with integrity checksum. • - OpenSource filesystem (but GPL incompatible) with real-time redundancy and integrity checksum.
• - OpenSource filesystem GPL2 with real-time redundancy. From Linux 3.9 it supports and integrity checksums. Recently various issues were found and the official now states: The parity RAID code has multiple serious data-loss bugs in it.
It should not be used for anything other than testing purposes. • - The last contender from Microsoft, and integrated into Windows 8. Proprietary with real-time redundancy. Checksumming is not supported.
UnRAID - Commercial and OpenSource GPL2 solution. A modified version of. SnapRAID, unRAID, FlexRAID, ZFS, Btrfs, Storage Spaces. Number of failures. AuthorTotal downloads 413Uploaded6.11.2007Activation code/Serial key1234-7148-8668-6181 Important! If the activation code or serial key does not fit, download and generate NEWChecked Dr.Web No virusesLink: To download the “unraid crack or serial or keygen” one file you must go to one of the links on file sharing.
It also has some other. The main factor to categorize them is when the redundancy information is updated. In real-time solutions the parity data is updated in real-time, without an explicit action from the user. Like in standard RAID. In snapshot solutions the parity data is updated only upon an explicit request from the user.
Like in backups. Other important factors are the support of an integrity checksum to identify and the possibility to fix it, if you can use already filled disk, if you can recover your data from not broken disks when you get too many failures to have a full recover, and if all your disks are spinning when reading one file. SnapRAID unRAID FlexRAID ZFS Btrfs Storage Spaces Redundancy model Real-time computes parity at real-time like RAID, snapshot at request time, like Backup. Snapshot Real-time Real-time Snapshot Real-time Snapshot Real-time Snapshot Real-time Integrity If data is validated with some kind of checksum, and which one is the default.
Yes SpookyHash 128 bit No Yes Adler32 32 bit Yes fletcher4 256 bit Yes CRC32C 32 bit No Fix silent errors If silent errors are detected and fixed before they can propagate into the parity. Yes No No Yes Yes No Number of failures How many disk failures are supported? 1 is for RAID5, 2 for RAID6. 1 2 3 4 5 6 1 2 1 2 3 4 5 6+ 1 2 3 1 2 1 2 Other failures If more disks fail than the supported redundancy model, is it possible to recover the data in the not failed disks? Yes Yes Yes No No No Power/Noise How many disks are spinning when reading a single file? One One One All All All Filled disks Can you start with already filled disks? Yes Partial Yes No No No Add disks Can you add disks at later time?