[Epic 4G General] sonarchist:
Observations: BML/MTD Conversion + mSD Card Performance

My own path for New Year's Day led to conversion of my favorite custom ROM, Legendary 2.2, from BML-ext4 to MTD-yaffs2 ......... following the advice of tortel1210 + edfunkycold, I took the most recent Legendary2.2 nandroid that I had in my sd card, and converted the ext4 files over to yaffs2..........ran the restore from ClockworkMod Recovery v. 5.0.2.7, and, in about five minutes there it was: Legendary2.2_MTD.............approx. 200 MB extra memory gained and on an entirely new file partition system.

Right about then, uberpinquin had announced the release of CyanogenMod 7's Release Candidate Official_v7.2.0, only to up the ante a few days later on January 4th with the announcement of CM7_RCOv7.2.0_w/epic-wimax............the expanded 4G functionality made front page xda news!

...............A fond follower of CyanogenMod's earlier versions thru CM6 on other devices, I was only too glad to flash CM7 onto the EPIC (right on top, wiping Legendary2.2MTD...no worries, would begin alternating back/forth btwn these 2 ROMs hours later!)...........and begin my own 'test' phase for the Nightlies (from '0' thru '16', at this writing). Prior experiences w/ Cyanogen (non-Epic) had been 100% experimental: tons of tinkering and never 100% daily driver material .........yet, fascinating stuff + lots of trial and error good fun (w/ each incremental advancement)........so flashing Official CM7w/wimax was a particularly happy moment.

................this was follwed by two weeks of: (a) migrating back and forth between CM/MTD ROMs + TW/MTD ROMs.........(b) testing different 3rd party CM/MTD or TW/MTD Kernels (careful: keep these paired together, IOW, a TW kernel will not work on a CW ROM, and vice versa!); as well as (c) running ODIN to wipe from MTD back to Stock EC05 Froyo BML baseline (careful here too: in addition to known ODIN wipe method, you must place 'victory.pit' in ODIN and select 'repartition' or MTD will not convert back to BML Stock!).

.................so at any given point we are running the gamut MTD/CM/TW/BML/MTD (+ ODIN!)........this leads me to the purpose of this post:

Here are a few notes of my recent personal observations of how the arrival of MTD is changing our rule book to a tiny extent (+ how this is possibly having an effect on microSD Card 'data-load' activity, at the very least in the short term):

1.......feels like we are re-mapping the rules for the EPIC and an MTD future (with the profound foundation of ODIN + BML Stock which allows us to experiment and ultimately recover --then begin the process w/ a perfectly 'clean' wipe-- + continue building/flashing that perfect new custom ROM for the EPIC4G.........or to sample from all of the MTD variants that are currently out there, thanks to our fine devs here on XDA!)

2.......with the flurry of activity --jumping from MTD to BML, from CM/MTD to TW/MTD-- the mSD Card is writing and reading data ONLY as fast as it is made to do: for example, class 2 = 2 Mbps, while class 10 = 10Mbps...............add to this the apps2SD type activity, moving apps back and forth from the SD card to regular memory and vice versa.........let alone TB batch restore of apps w/ each time that you jump from one ROM to the next.

3.......same w/ CWM-Recovery activity: restoring your favorite MTD nandroid, only to flash a new ROM release, then back to restore to your favorite MTD nandroid from recovery (if the new release is a 'no-go'), or else an Advanced Restore of 'data' only from your nandroid (instead of batch restore) ................ again, lots of read/write activity on the SD card: it can take it!

4......CM7: when flashing nightlies, some of us have experienced 'missing' apps in the app tray, yet they are present when you view settings / applications ............... additionally, some users have experienced erratic behaviour running HD-video (dropped frames, ie, choppy playback of recorded material), + YET others have reported problems w/ CM7 that seem to point to data issues having to do w/ the read/write capacity of the microSD Card or its failing controller..............my guess: with the daily increase in activity it may be time to consider a faster card as it has been speculated that older SD Cards are partially the cause of some of these issues (tho it has also been argued that the EPIC's processor will limit read/write speeds as well) ........... IMO, we each have to adjudge what is going on with our own devices based on personal benchmarks + results.

5......lastly, it's been a bit of a wrestling match getting FolderSync to synchronize my MTD nandroids to the cloud DIRECT from my EPIC (WITHOUT a pc), here's an earlier post related to this issue:

http://xdaforums.com/showpost.php?p=20976549&postcount=2848

ITMT, until further notice :) , I have reverted to my prior backup regime, which is as follows: using SyncToy, transfer my Epic nandroid to PC, then to PC to SkyDrive via windowsLiveMesh; here are a few results:

FolderSync to Dropbox - Direct fr EPIC4G

Legendary2.2MTD_Nandroid (503MB)

Successful......2.0 hours w Legendary / 3.5 hours w CM7 (?)

FolderSync to Dropbox - Direct fr EPIC4G

CyanogenMod7_Nightly15_Nandroid (424MB)

......3.5 hours, sync pushed 6 files from PC to dropbox successfully (one file.....data yaffs2 = FAILed to Sync)

message from FolderSync:

error: SYNC Failed: org.apache.http.client.ClientProtocolEncryption

*it should be noted, 3.5 hrs incl. 6 separate attempts to sync 'data.yaffs2' file.

SyncToy Device to PC; then synchronize PC to SkyDrive, via windows LiveMesh.

Legendary2.2_MTD_Nandroid (503MB)

Successful......2 hours 15 minutes.

SyncToy to PC; then synchronize to SkyDrive, via win LiveMesh.

CyanogenMod7_Nightly15_Nandroid (424MB)

Successful.......1 hour 15 minutes.

CONCLUSION:

The Best Practices mSD Card + Data Failure Prevention Guide is under evaluation (+ construction) at the moment...........please stay tuned for the total MTD re-map!!!!!!

:) :) :) :) ;)

*edit: as i was completing the SkyDrive sync for CM7, an update appeared from winLiveMesh/SkyDrive......so I ran it, then began the next Sync --Legendary2.2MTD-- so have not stopped to read what differences, if any, the new version of LiveMesh brings to the table (*quick edit#2: update provides speed enhancements + geomapping for person doing the uploading only, NO geomapping data for those that download the material).

.........thing I enjoy, most w/ this method: running a sync to SkyDrive allows you to use your pc during the process, which is how I wrote THIS POST --while waiting for Legendary2.2MTD to complete the sync process!

.........running a sync direct from the EPIC to dropbox, your device is pushing the sync so you have to wait for the process to complete before you're fully able to use your device :( or NOT! it's your device, it'll get plenty hot tho!

.........to clarify: as part of my personal recovery Best Practices strategy I like keeping a single 'ER-Nandroid' (TW/MTD, CM/MTD, BML) on cloud storage........then I can download directly to my device (or OTHER device); if emergency conditions required me to do so, or if I just wanted to let a friend far far away to be able to share my personal 'custom' set-up, THERE IT IS, a simple download away!........I just like keeping those kinds of options open ;)

.....................as always, mileage varies per device w/ all of the methods described in this thread.