Update README.
This commit is contained in:
41
README.adoc
41
README.adoc
@@ -1,41 +0,0 @@
|
|||||||
= kramer
|
|
||||||
:toc:
|
|
||||||
|
|
||||||
// Hello people reading the README source :)
|
|
||||||
|
|
||||||
== Prelude
|
|
||||||
|
|
||||||
VERY EARLY ALPHA -- NOT YET FUNCTIONAL
|
|
||||||
|
|
||||||
I needed a program to efficiently repair the data on optical discs.
|
|
||||||
|
|
||||||
== Goals
|
|
||||||
|
|
||||||
* [*] CLI Args
|
|
||||||
** [*] Input device
|
|
||||||
** [*] Output file (ISO 9660)
|
|
||||||
** [*] Repair map file
|
|
||||||
** [*] sequence_length
|
|
||||||
** [*] brute_passes
|
|
||||||
** [*] Sector size override?
|
|
||||||
|
|
||||||
* Repair Algorithm
|
|
||||||
** Stage 1: Trial
|
|
||||||
*** [ ] 1 - From first sector, parse forward to error.
|
|
||||||
*** [ ] 2 - From last sector, parse backwards to error.
|
|
||||||
*** [ ] 3 - From center of data for trial, parse forward to error or end of remaining trial domain.
|
|
||||||
*** [ ] 4 - Stripe-skip remaining data, attempting to read largest trial domains first.
|
|
||||||
**** [ ] If data keeps reading good, no skip will occur until an error is reached.
|
|
||||||
** Stage 2: Isolation
|
|
||||||
*** [ ] From largest to smallest untrustworthy sequence, attempt to read each sequence at half sequence_length.
|
|
||||||
*** [ ] Same, but at quarter sequence_length.
|
|
||||||
*** [ ] Same, but at eighth sequence_length.
|
|
||||||
*** [ ] By sector, parse untrustworthy sequences from start to error, and end to error. Mark mid section for brute force.
|
|
||||||
** Stage 3: Brute Force
|
|
||||||
*** [ ] Desperately attempt to recover data from marked sections.
|
|
||||||
*** [ ] Attempt for brute_passes, retrying all failed sectors.
|
|
||||||
|
|
||||||
* [ ] Repair Map
|
|
||||||
** [ ] I'll figure out some kind of language for this...
|
|
||||||
|
|
||||||
== License
|
|
||||||
74
README.md
Normal file
74
README.md
Normal file
@@ -0,0 +1,74 @@
|
|||||||
|
# kramer
|
||||||
|
|
||||||
|
`kramer` is a data recovery utility for optical media.
|
||||||
|
|
||||||
|
There are plans to change the project name, but during initial development it
|
||||||
|
will continue to be referred to as kramer.
|
||||||
|
|
||||||
|
This is still in very early development, so expect old maps to no longer work.
|
||||||
|
|
||||||
|
## Plans
|
||||||
|
|
||||||
|
### Core
|
||||||
|
|
||||||
|
- [x] Mapping
|
||||||
|
- [x] Record the state of disc regions
|
||||||
|
- [x] Recover from saved map.
|
||||||
|
- [ ] Recovery
|
||||||
|
- [x] Initial
|
||||||
|
Technically there is an outstanding issue with sleepy firmware here,
|
||||||
|
but beside that this technically works.
|
||||||
|
- [ ] Patchworking
|
||||||
|
- [ ] Isolate
|
||||||
|
- [ ] Scraping
|
||||||
|
- [ ] CLI
|
||||||
|
- [x] Arguments
|
||||||
|
- [ ] Recovery progress
|
||||||
|
- [ ] Recovery stats
|
||||||
|
- [ ] Documentation, eugh.
|
||||||
|
|
||||||
|
### Extra
|
||||||
|
|
||||||
|
- [ ] i18n
|
||||||
|
- [ ] English
|
||||||
|
- [ ] French
|
||||||
|
- [ ] TUI (akin to `ddrescueview`)
|
||||||
|
- [ ] Visual status map
|
||||||
|
- [ ] Recovery properties
|
||||||
|
- [ ] Recovery progress
|
||||||
|
- [ ] Recovery stats
|
||||||
|
|
||||||
|
|
||||||
|
## Recovery Strategy
|
||||||
|
|
||||||
|
### Initial Pass (Stage::Untested)
|
||||||
|
|
||||||
|
Tries to read clusters of `max_buffer_size`, marking clusters with errors as
|
||||||
|
`ForIsolation` (note that the name has not yet be updated to
|
||||||
|
`Patchwork{ depth }`).
|
||||||
|
|
||||||
|
### Patchworking
|
||||||
|
|
||||||
|
This works by halving the length of the read buffer until one of two
|
||||||
|
conditions is met:
|
||||||
|
|
||||||
|
1. `max_buffer_size` has been divided by `max_buffer_subdivision`
|
||||||
|
(like a maximum recursion depth).
|
||||||
|
Effectively, it will keep running `max_buffer_size / isolation_depth;
|
||||||
|
isolation_depth++;` on each pass until `isolation_depth ==
|
||||||
|
max_buffer_subdivision`
|
||||||
|
2. `buffer_size <= min_buffer_size`
|
||||||
|
3. `buffer_size <= sector_size`
|
||||||
|
|
||||||
|
### Isolate
|
||||||
|
|
||||||
|
This is where we reach brute forcing territory. `ddrescue` refers to this as
|
||||||
|
trimming. `kramer` implements the same technique. However, thanks to the
|
||||||
|
patchworking pass, this sector-at-a-time reading can be minimized, hopefully
|
||||||
|
reducing wear and overall recovery time on drives with a very short spin-down
|
||||||
|
delay.
|
||||||
|
|
||||||
|
### Scraping
|
||||||
|
|
||||||
|
This is the pure brute force, sector-at-a-time read. This has identical
|
||||||
|
behaviour to `ddrescue`'s scraping phase.
|
||||||
Reference in New Issue
Block a user