Hi all,

I've been working on something which I feel is a bit special. RAID-1 for the Amiga. I've done a soft-release (just to my website) pending some beta testing.

I'm running it here and if any brave souls would like to try it, then it's available from https://www.zeusdev.co.uk/

I have only tested with OS3.9!! This is my major gap to a full release, a
need to test on 3.0/3.1/3.2.


Zeus RAID 1.0
=============

Zeus RAID solves a long term problem that I've had with the Amiga.

Reliability. The idea that something can fail in a system yet it either
carries on or at least you don't lose your data. Specifically, reliability of storage.

Backups are one thing and that's a reasonably solved problem (though perhaps still with room for improvement!) but restoring a backup still means you're offline for a while.

RAID is a solution to the common problem of disk failures.

I've been very fortunate in that regard, and have lost only maybe three disks on Amigas in 30+ years. But along career in IT has exposed me to not just the constant failure of disks, but also all sorts of interesting server hardware and software to mitigate that problem.

I'm a glutton for punishment so most of my Amigas are using real spinning disks, often SCSI, but don't think SSDs and similar are not vulnerable to failures themselves. You still need protection.

This is where Zeus RAID comes in.

Zeus RAID keeps two identical copies of a partition on two disks. If one
disk fails, your files are still on the other, and the Amiga carries on
working without a pause. This is "RAID-1", or mirroring.


Features
--------

o Mirrored writes to two partitions on two different disks.
o Degraded running: a disk that reports an error is dropped and the
array keeps going on the survivor. A requester tells you.
o Online rebuild: add a replacement disk and it is copied in the
background while the volume stays in use.
o Fast recovery after a crash or reset: a write-intent bitmap means
only the regions being written at the time are re-copied, not the
whole disk.
o Online check and repair, comparing both disks while in use.
o Read modes: read from the master only, or split reads across both
disks for speed.
o Arrays up to 2TB.
o Built from your existing partition: create an array from a partition
that already holds data, and it is mirrored onto the second disk.
Nothing is reformatted.
o Fully reversible: DELETE puts the original partitions back as they
were, from the backups kept in DEVS:ZRAID/.
o Easy to use via ZeusRAID, an MUI configuration and status tool.
o ZeusRAID Shell command for scripts.
o Localised in 13 languages: English, Deutsch, Francais, Nederlands,
Espanol, Portugues, Italiano, Svenska, Norsk, Dansk, Suomi, Polski
and Cymraeg. (Machine translated - apologies if there are poor
translations!)
o A full AmigaGuide manual.

Requirements
------------

o AmigaOS 3.0 or later (tested on 3.9).
o Two partitions on two different physical disks.
o MUI for the GUI (optionally).

Limitations
-----------

o RAID-1 only, two disks per array.
o You cannot boot from an array: system/OS is not supported on RAID.

Testing
-------

Zeus RAID was tested on an WinUAE with automated stress tests, edge cases and simulated failures: disk failure and replacement, losing the master disk, damage detection and repair, resets in the middle of writes, and heavy use.



--
Neil Williams - SysOp of TKG BBS
Zeus Developments
... Zeus Developments

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