Has anyone tried to repartition our /system and /data folders to create an /emmc partition for our phones? Seems like OE partitioning scheme is a huge waste of space and we could better utilize the extra space if it was in user mountable partition.
This should be easy to do via recovery yes?
Sent from my MB865 using xda premium
unsivil_audio said:
Has anyone tried to repartition our /system and /data folders to create an /emmc partition for our phones? Seems like OE partitioning scheme is a huge waste of space and we could better utilize the extra space if it was in user mountable partition.
This should be easy to do via recovery yes?
Sent from my MB865 using xda premium
Click to expand...
Click to collapse
Yes both lfaber06 and I sort of do something similar, with the way we have safestrap setup, but we use the SDcard instead. The one issue I see with this is what the future brings for this phone, like what moto might do for us with ICS, and such, what may be needed in these partitions to make it work. Other that that I don't see an issue, but you will have to change a ton of start scripts if the partition numbers change.
Jim
Sent from my MB865 using xda premium
I don't think you understand, I want the space to be user accessible, like I have on my nook. I flashed a custom repartition from cwm to resize data and media partitions. The /emmc partition is a fat32 partition I believe (on my nook anyways). I've never even come close to filling my 2gb data partition, and now I have 4gb of space for music or videos storage.
unsivil_audio said:
I don't think you understand, I want the space to be user accessible, like I have on my nook. I flashed a custom repartition from cwm to resize data and media partitions. The /emmc partition is a fat32 partition I believe (on my nook anyways). I've never even come close to filling my 2gb data partition, and now I have 4gb of space for music or videos storage.
Click to expand...
Click to collapse
No, I don't think you understand what that really does under the covers. Both lfaber06 and I have been working on this device for a while, we are the ONLY two devs currently working on this device. What I am telling you is that if you change the size of ANY of the internal partitions, It might effect the ability to update to another version of Android. Your Nook, is not a Mototrola device, and Moto has completly messed with/up android, and therefore it is not safe to do what you are saying. No matter what you can not get access to the internal partitions, yes on AOSP devices / devices that can be AOSP (the nook is one), you can do those things. The Atrix2 still has a locked bootloader, so we are stuck with their kernel, and version of android. To do what you are saying you will need to have an AOSP kernel, and have MANY init scripts updated to understand the new partition table. It is not as easy as you make it out to be.
Okay, I was under the impression with rw abilities on /system and /data partitions we also have the ability to mount, unmount; also giving us the ability to edit the partition blocks via bootstrap.
Ok how about this, there is a guy in the Nook Tablet forum (locked bootloader, like us) who had the idea of basically running a fat32 "img" that in the /data (ext4) partition to that would mount via a script and be user accessible? That would be possible I would think.
unsivil_audio said:
Okay, I was under the impression with rw abilities on /system and /data partitions we also have the ability to mount, unmount; also giving us the ability to edit the partition blocks via bootstrap.
Ok how about this, there is a guy in the Nook Tablet forum (locked bootloader, like us) who had the idea of basically running a fat32 "img" that in the /data (ext4) partition to that would mount via a script and be user accessible? That would be possible I would think.
Click to expand...
Click to collapse
Yes you do have access to all of those things with root, but Moto has done so much customization to this thing, that would not be safe.
Yes, that is also something that lfaber06 and I have thrown around as well, the logistics of it need to be worked out for our phone, and the proper init scripts need to be put together.
Are you up for the task? I only ask because he and I are currently working on porting cm7 and cm9 to our phone, which is a huge task. I can help you out, but I just can't take on anymore projects for this phone at the moment, since I have 5 different things I am working on for us right now.
I am definitely down to help, still going to be a bit of a learning curve for myself. Still pretty new to linux/android.
unsivil_audio said:
I am definitely down to help, still going to be a bit of a learning curve for myself. Still pretty new to linux/android.
Click to expand...
Click to collapse
PM me, with as much info as you have about this, preferably any links that you have read, and I will help you develop a game plan, and what you will need to make this hack happen. You will have to do some research on your own, and I can help with the Linux/Android part, and help you figure out what you will need to do. I am also not sure on the what kind of speed to expect from something like this, so that will also be something to look into, since this will be a virtual disk file.
Related
Yes, I have searched; don't give me the whole guilt crap
I would like to know a couple of things...
1. Internal phone storage & phone memory, what is the difference and is there any mods people are doing with them as far as combining or something?
2. SD partitioning... are people still doing this and if so what are you recommending?
3. Swap... probably a thing of the past, but just would like to know.
Class 4 32gb
Running Weapon G2X
Faux stock kernels
Clockwork EXT4
alright lets make this world a better place, i'll tell you what i know
internal storage, is basically yours to use, add your music pics or whatever, just like how u use an sd card, phone memory aka application memory is reserved for apps only, no way of combining them, dont need to anyways, sd partitioning i never tried but i think its says it all, dividing your sd card into two or more partitions..make seem like you have two or more, u can reserve one just for music or pics or roms
and what do u mean by swap??
ooh yah if i helped a little hit the thxs button, imma collect now too lol
I came from from the G1 where it was standard practice to partition into fat32/ext/swap. Since moving to the G2x I have not needed it. Phone is super fast without swap and more than enough space for apps.
As for combining internal and external SD cards, I don't think I've seen that yet...
Sent from my LG-P999 using Tapatalk
I've never seen them combined but don't know if you can because if you remove the microsd, it would get all screwy.
I don't even use internal unless the rom does. I have a collection of apks/walls/music and my titanium files on my SD... everything else is expendable.
Sent from my LG-P999 using xda premium
player911 said:
I've never seen them combined but don't know if you can because if you remove the microsd, it would get all screwy.
I don't even use internal unless the rom does. I have a collection of apks/walls/music and my titanium files on my SD... everything else is expendable.
Sent from my LG-P999 using xda premium
Click to expand...
Click to collapse
and with those on the SD are you using them just anywhere on the SD or do you have an EXT 4 partition?
dylyxcore said:
Yes, I have searched; don't give me the whole guilt crap
I would like to know a couple of things...
1. Internal phone storage & phone memory, what is the difference and is there any mods people are doing with them as far as combining or something?
2. SD partitioning... are people still doing this and if so what are you recommending?
3. Swap... probably a thing of the past, but just would like to know.
Class 4 32gb
Running Weapon G2X
Faux stock kernels
Clockwork EXT4
Click to expand...
Click to collapse
Internal phone storage is where your system files are stored. It is also where apps from the market are installed. Phone memory is utilized by the stock roms as the default "sdcard". By default this is where your photos, music, documents, etc are stored. There is also an external slot for a physical sdcard. This is actually mounted to /sdcard/_ExternalSD with a stock rom.
There is no need to partition the external sdcard. There is enough space on the phone by default and it probably wouldn't be worth the hassle to make it work.
I don't think you need swap with this phone.
phburks said:
Internal phone storage is where your system files are stored. It is also where apps from the market are installed. Phone memory is utilized by the stock roms as the default "sdcard". By default this is where your photos, music, documents, etc are stored. There is also an external slot for a physical sdcard. This is actually mounted to /sdcard/_ExternalSD with a stock rom.
There is no need to partition the external sdcard. There is enough space on the phone by default and it probably wouldn't be worth the hassle to make it work.
I don't think you need swap with this phone.
Click to expand...
Click to collapse
Thank you for clearing this up, so in clockwork recovery why does it support EXT 4? Is that just the format it saves a back-up in?
dylyxcore said:
Thank you for clearing this up, so in clockwork recovery why does it support EXT 4? Is that just the format it saves a back-up in?
Click to expand...
Click to collapse
No. Ext4 is a type of filesystem used commonly in Linux, just like FAT and NTFS are used with Windows setups. There are some roms that will mount your system as, or even fully format your system into a ext4 filesystem. Clockwork supports that filesystem, meaning it can be used to install ext4 roms.
phburks said:
No. Ext4 is a type of filesystem used commonly in Linux, just like FAT and NTFS are used with Windows setups. There are some roms that will mount your system as, or even fully format your system into a ext4 filesystem. Clockwork supports that filesystem, meaning it can be used to install ext4 roms.
Click to expand...
Click to collapse
Thank you for your help, one last thing... to run these do you need an EXT 4 partition, or is that completely different? What makes the ROM to be EXT 4?
dylyxcore said:
Thank you for your help, one last thing... to run these do you need an EXT 4 partition, or is that completely different? What makes the ROM to be EXT 4?
Click to expand...
Click to collapse
No you simply flash like you would any other rom. If the rom actually formats your drives to ext4 i beleive you will have convert back to ext3 in order to flash an ext3 rom. There is a conversion utility somewhere on here if you search around. Someone else wanna chime in to verify about the need to convert back to ext3?
phburks said:
No you simply flash like you would any other rom. If the rom actually formats your drives to ext4 i beleive you will have convert back to ext3 in order to flash an ext3 rom. There is a conversion utility somewhere on here if you search around. Someone else wanna chime in to verify about the need to convert back to ext3?
Click to expand...
Click to collapse
Yeah I read about the EXT 3 to EXT 4 dilemma on here via CM7 when it was upgraded from an overnight build or something... I think it had to do with restoring apps or data? Really appreciate your information, this finally clears up the confusion
p.s. thanks'ed all your replies
Noticed today I'm able to move almost all of my apps to SD and not just the supported ones without having done anything but installing a rooted stock ROM and some standard goodies (SU, BusyBox, ROM Manager and Titanium Backup). Wondering if it was enabled by any of the above? the rooted ROM? or the stock ROM?
any takers?
Titanium backup, in "batch", has option to move all apps to either sd or internal memory.
Sent from my myTouch_4G_Slide using xda premium
It's not true A2SD. Just a bunch of buggy symlinks in /data and incomprehensible files in /sdcard/.android-secure that Google is trying to pass off as A2SD.
Sent from a message in a bottle.
blackknightavalon said:
It's not true A2SD. Just a bunch of buggy symlinks in /data and incomprehensible files in /sdcard/.android-secure that Google is trying to pass off as A2SD.
Sent from a message in a bottle.
Click to expand...
Click to collapse
thanks. i rooted my phone right after the first stock boot so i couldn't tell if it came that way. It's just odd coming from 2.2 that everything all of a sudden is now movable, despite being not true a2sd.
psychedel!k said:
thanks. i rooted my phone right after the first stock boot so i couldn't tell if it came that way. It's just odd coming from 2.2 that everything all of a sudden is now movable, despite being not true a2sd.
Click to expand...
Click to collapse
I know. Just because a bunch of people find hitting "partition SD card" in ClockworkMod Recovery too difficult doesn't mean those of us who want the full potential of our phones unlocked should suffer, but we're stuck until someone finds us the mountpoint for sd-ext.
blackknightavalon said:
I know. Just because a bunch of people find hitting "partition SD card" in ClockworkMod Recovery too difficult doesn't mean those of us who want the full potential of our phones unlocked should suffer, but we're stuck until someone finds us the mountpoint for sd-ext.
Click to expand...
Click to collapse
you all need to check out link2sd (free app) it will let you install apps to ext partition. I myself use it and have a 8gb ext3 partition with over 550+ apps/games installed. It also lets you decide if you want to move dalvikcache and library files to ext to save more internal space. I used mini tool partition app on my pc to create a larger ext partition then cwm would allow.
Sent from my LG-P999 using xda premium
d12unk13astard said:
you all need to check out link2sd (free app) it will let you install apps to ext partition. I myself use it and have a 8gb ext3 partition with over 550+ apps/games installed. It also lets you decide if you want to move dalvikcache and library files to ext to save more internal space. I used mini tool partition app on my pc to create a larger ext partition then cwm would allow.
Sent from my LG-P999 using xda premium
Click to expand...
Click to collapse
I'll try it on my days off. Thanks for the tip!
Sent from a message in a bottle.
blackknightavalon said:
..we're stuck until someone finds us the mountpoint for sd-ext.
Click to expand...
Click to collapse
sorry can you explain how and where we're stuck on and is that specific to our device?
blackknightavalon said:
I know. Just because a bunch of people find hitting "partition SD card" in ClockworkMod Recovery too difficult doesn't mean those of us who want the full potential of our phones unlocked should suffer, but we're stuck until someone finds us the mountpoint for sd-ext.
Click to expand...
Click to collapse
psychedel!k said:
sorry can you explain how and where we're stuck on and is that specific to our device?
Click to expand...
Click to collapse
WIP Memory Address Listing
You need to know where to put and access the data, explicitly, in order to be able to use that location.
Android does this by using mount-points, which translates to the memory address where it should be looking for the information.
The thread I linked to is one I started so that we can discover them all, and what mount points correspond to what memory address.
Please make sure to read post number 8 in the thread by dhkr234 which spells out a good caution about using memory addresses directly and why you should be using mount points instead.
If anyone makes any headway in learning anything we don't know so far, please post it in that thread so we can get a comprehensive listing of mount points and what memory addresses they correspond to.
I've been extremely busy on other projects, but if someone is going to come by and make A2SD available for us, having a road-map for them to follow already sitting here will make their life a lot easier. ( ...and maybe encourage someone to do it because the info is sitting there. )
...and yes, it is specific to our device. Every device addresses the internal memory differently and that makes the mount-points unique to each and every device.
gotcha, so...piecing this all together, does that mean that a true A2SD shouldn't rely on symlink at all and Link2SD (what d12unk13astard recommended) is essentially just another hack?
psychedel!k said:
gotcha, so...piecing this all together, does that mean that a true A2SD shouldn't rely on symlink at all and Link2SD (what d12unk13astard recommended) is essentially just another hack?
Click to expand...
Click to collapse
The real A2SD is not "just another hack," it's one of the ORIGINAL post-root hacks pioneers like JesusFreke came up with. It allows you to put your apps on an EXT partition of your SD card, and you can resize that partition if your computer runs a Linux distribution.
blackknightavalon said:
The real A2SD is not "just another hack," it's one of the ORIGINAL post-root hacks pioneers like JesusFreke came up with. It allows you to put your apps on an EXT partition of your SD card, and you can resize that partition if your computer runs a Linux distribution.
Click to expand...
Click to collapse
that i got, and sorry for being a pain..so then what difference does having a mountpoint or not make?
psychedel!k said:
that i got, and sorry for being a pain..so then what difference does having a mountpoint or not make?
Click to expand...
Click to collapse
Read the previous posts.
psychedel!k said:
that i got, and sorry for being a pain..so then what difference does having a mountpoint or not make?
Click to expand...
Click to collapse
Either:
blackknightavalon said:
Read the previous posts.
Click to expand...
Click to collapse
Or read this one again:
http://forum.xda-developers.com/showpost.php?p=19163237&postcount=8
dhkr234 said it good there.
I linked so someone who wants more of an explanation can follow and read up.
In short, you can very easily write to the wrong memory address.
This means:
Installing some silly game over parts of both your boot partition and recovery partition would give you a cool slide-paperweight.
Mount points prevent this from happening by ensuring the data is written to the proper memory addresses.
With all the lighter custom ROMs we have today, the default huge /system partition we have in the O3D is a waste of space. Same with the /data partition. For those who don´t know, both /system and /data (and other smaller ones) are actual internal SD Card space!
That´s why we have LG specs saying we have 8GB of internal flash storage, when in fact we have just 5.5GB available.
So my question is: is there a (safe) way to wipe all internal SD partitions and then recreate them with more appropriate sizes, earning back all the wasted space?
Thanks a lot!
Marcovecchio said:
With all the lighter custom ROMs we have today, the default huge /system partition we have in the O3D is a waste of space. Same with the /data partition. For those who don´t know, both /system and /data (and other smaller ones) are actual internal SD Card space!
That´s why we have LG specs saying we have 8GB of internal flash storage, when in fact we have just 5.5GB available.
So my question is: is there a (safe) way to wipe all internal SD partitions and then recreate them with more appropriate sizes, earning back all the wasted space?
Thanks a lot!
Click to expand...
Click to collapse
Have you read about data2ext? I think it would be a very good solution to us.
Sent from my LG-P920 using XDA App
Thanks for the reply, ThiaiZ!
However, I think I´m looking for something different: as far as I know, data2ext changes the /data partition pointer to external memory (SD Card), so the original /data partition will never be used by the OS, and it´s space will be wasted, right?
I would like to find a way to get this wasted space back! If we could repartition /system, /data, /cache, to smaller sizes, we would have more storage space for stuff on the internal SD. Does it make sense? Thanks!
Well, since I had no solutions here, I would like to post some examples of this for other phone models:
MyTouch 3G Slide - http://forum.xda-developers.com/showthread.php?t=893706
LG GT540 - http://forum.xda-developers.com/showthread.php?t=1171531
The MyTouch 3G Slide thread is particularly good because it explains in detail how to check the partition sizes, and shows how much space is wasted on the /system partition.
Marcovecchio said:
Well, since I had no solutions here, I would like to post some examples of this for other phone models:
MyTouch 3G Slide - http://forum.xda-developers.com/showthread.php?t=893706
LG GT540 - http://forum.xda-developers.com/showthread.php?t=1171531
The MyTouch 3G Slide thread is particularly good because it explains in detail how to check the partition sizes, and shows how much space is wasted on the /system partition.
Click to expand...
Click to collapse
Don't we have to be s-off to be able to resize the partitions ?
I did it a lot on my HTC Desire.
BTW do you have any idea in which block data and sd-ext are mounted on our device ?
I believe the S-OFF flag exists only in HTC devices. I read that somewhere here, at XDA. The guy seemed to know what he was talking about, and he said LG never implemented any kind of protection like S-ON / S-OFF.
About the block names, I believe you can list the blocks and the partition names they´re mounted as, with the "df" command. I know almost nothing about Linux, and even less about how Android manage it´s partitions, but that would be nice to be able to tweak their sizes...
LG GT540's partitions can easily be resized by flashing an MBN file. Don't know if this phone can get that done too
http://forum.xda-developers.com/showthread.php?t=1171531
Don't try resizing partitions.
You'll brick your phone.
Hi,
This has been asked many times before with no real solution that applies to different devices.
I'm running out of space on my /system partition and can't install any more apps even though I don't have that many installed.
I want a way to re-size the Android partitions manually to whatever size I want. Or just delete all current partitions and create new ones.
How do I do that? Is there any GUI partitioning tools similar to the ones available for Windows?
I don't want to move files from /system to another partition. I want to change the partition size.
My current /system partition:
For what reason are you moving apps to /system? You can't install them there, you have to push/move them there, installs go to /data. So keep them in /data, where they're installed by default. You have tons of space available there.
Partition table (start addresses and sizes) is hard-coded in bootloader, and can be redefined in kernel boot parameters (in this case recovery needs to be recompiled with the same parameters too, otherwise it won't write to the same partitions the kernel will read from). You're welcome to hack any of those. As you could probably understand from this paragraph, I wouldn't expect having GUI tools for that.
Thanks for the reply.
I'm not trying to move apps to /system. I thought apps are installed there by default because every time I try to install a new app it gives me an error message saying that there is not enough space on /system.
Now I know that apps are not installed in /system.
I just need more space in /system so I can install new apps without any errors.
What can I do to get more space on /system partition? Can I replace the bootloader?
I don't have any Android programming experience. I probably need something that is available out there to do the job.
In stock form, you shouldn't even have write permissions to /system. Nothing should be ever written there, and it can be 99.99999% utilized - there shouldn't be any free space left for anything, it shouldn't normally be used.
If you're getting that error when trying to install an app - you need to check what's reporting the error. It's not a "real" error, it means there's something wrong with your phone.
Try wiping cache partition from recovery...does this make any difference?
Jack is correct.
Swyped from my DesireS
refer to this
if this may help you http://forum.xda-developers.com/showthread.php?t=1959691
:highfive:
mayank88288 said:
refer to this
if this may help you http://forum.xda-developers.com/showthread.php?t=1959691
:highfive:
Click to expand...
Click to collapse
Way to bump a year old thread :thumbup:
“I'm bad and I'm going to hell, and I don't care. I'd rather be in hell than anywhere where you are. ”*―*William Faulkner
The Hefe Hook kernel allows you to mount a partition of your microSD as /data, getting 2 GB (or more) for your apps and their data.
Please ask your questions here about installation, use, or general approach.
This is great @jeffsf and can u show me how to re-partition the "real internal" storage? I mean expanding the /system since u put the /data out of it. Thanks man
Sent from my GT-N7000 using Tapatalk 2
daothanhduy1996 said:
This is great @jeffsf can u show me how to re-partition the "real internal" storage? I mean expanding the /system since u put the /data out of it.
Click to expand...
Click to collapse
Yes, you've hit on another of the reasons I've been exploring using the microSD for "live" storage. It's one thing to use potentially slow storage for photos that you basically write once or "app to SD" where you read the APK at boot time, make sure your ODEX in the Davlik cache is good, then generally read from the internal-flash cache. It is another when that memory is being read and written "constantly" when your phone is running.
The good thing is that once /data is not part of the internal flash filesystem, you don't have to worry about one ROM (kernel) thinking it begins at one place and another saying it starts at another. Previously, if one ROM had one /system size and another and a different one, the next partition, /data, would look to be corrupt when you swapped ROMs.
As a warning, not all users have fast microSD cards. Some that say "Class 10" on them really are dogs, especially for small reads/writes. The "Class" ratings are for sustained writes, as you would have with a camera recording video. If your ROM is "external /data" only, or even defaults to that, be prepared for a slew of "Your ROMs sucks. It is so slow." complaints.
You'll also need a way to automate formatting the card. It can be done on the phone, as long as you aren't trying to preserve any data.
As I recall, the layout of the MTD partitions is done in drivers/mtd/onenand/samsung_galaxys4g.h I would be careful not to move the partition boundary for efs, as you'd have to move the data it contains in your updater script. Repeating the warning about not moving the boot and recovery partitions is probably a good idea as well!
Your build tree may need some of these values, or at least think it needs some of these values. For example, device/samsung/aries-common from the CyanogenMod/cm-11.0 (KitKat) branch calls out NAND page sizes, partition sizes, and flash block sizes. I haven't looked in detail at your build tree so I can't comment on how it might handle things differently than the CyanogenMod one.
itzik2sh said:
Hi
I hope I don't ask anything silly, but please let me know if any of my assumptions is wrong :
1. I take FBi's251's AOKP milestone 6 (ICS 4.0.4)
2. 8GB SDCard was formatted to FAT32 (4GB) and EXT3 (4GB) using TWRP kernel
(Beastmode's proton kernel to be exact).
3. I would flash this kernel and it would move apps and their data to the sd-ext
without any special additions.
Thanks. I read the thread, but unfortunately 8GB SD is what i have and I think it should be enough.
Thanks again.
P.S - it's for 2 guys I already sold them my SGS4Gs. I want them to be happy...
Click to expand...
Click to collapse
AOKP should be fine. I haven't tried it recently, but it was the tree in which I did the early Hefe Kernel development.
As I understand it, you have a microSD with
partition 1: 4 GB FAT32
partition 2: 4 GB ext3
So that can work, but will need some tweaking of the init-on-fs.sh script. I intentionally didn't use the second partition as so many scripts gobble that up as sd-ext and do who knows what to it.
My first preference would be to reformat the cards, perhaps:
6 GB FAT32
1 MB ext2/3/4 (Yes, 1 MB, a sliver, choice of ext2, ext3, ext4 up to you)
2 GB ext4
since then the script will work without modification and if they install a third-party script that uses the second partition, it won't corrupt their data.
If you were to keep the formatting the way that it is now, you'd need to edit the mount commands in the script to look something like:
Code:
/system/xbin/busybox umount /data
/system/xbin/busybox mount -t ext3 -o noatime /dev/block/mmcblk0p2 /data
(removing the sd-ext mount)
I'm not sure what your expectations are, but all that the kernel and that script will do is mount a different disk partition on /data -- you need to manually move the data over (or restore from something like Titanium Backup). There may be some trickery in renaming that could be used with TWRP backups to restore from data.yaffs2.win to the new /data partition, but I haven't tried that at all.
Hi Jeff
Thanks for your quick reply, and sorry again for not seeing the Q&A thread.
I think making it :
partition 1: 4 GB FAT32 (sdcard)
partition 2: 2 GB ext3 (sd-ext)
partition 3: 2 GB ext3 (data)
partition 4: 1 MB (spare)
would be better and handle data as well. don't you think ?
Would it be worth doing with a "Team" micro-SD card (class 6 I believe) ?
Thanks.
I haven't tried a Class 6 card, but my gut feeling is that it will be dicey. I didn't "commit" to using /data on microSD until I had tried it for several days using Titanium Backup's ability to move both apps and app data to the external card. I would try that first, especially as the phones in question aren't going to be in your hands (I consider you an expert user, able to manage things outside the UI with ease).
I've attached some testing I did a while ago with Transcend and SanDisk cards. When you look at them, realize that the speed scale changes between them. I have a feeling that the real "performance" on a device is going to be related to relatively small reads and writes, not the ability to stream video to the card. I also don't know much about the Team brand, but I found that even some well-known brands didn't have the performance of the Transcend or SanDisk in the same category.
However you configure your cards, I would definitely recommend a journaling filesystem of some sort. I've had my microSD come loose inside the phone. The journal will at least help to reduce any filesystem corruption should that happen.
You don't need the fourth partition -- I have it there to be able to keep rsync backups for fast ROM swapping.
.
Regarding the apps data, have you tried exploring the Mount2SD script ?
sent from me
I've tried a couple of the scripts out there in the past. Since backing up my data is very important to me, I trust the scripts in Titanium Backup to work well with its backup/restore strategies.
Mounts2SD looks like it has gotten a lot more sophisticated than it was when I tried it in the past. It sounds like something worth trying in its current state. At a quick glance (and not looking at the code), I'd personally make some different choices about features; enabling journaling, and being concerned about why lost+found was filling up (things should only appear there if the file system is found to be corrupt).