I've been learning to edit and make ROMs for couple of months, some of the early works had been uploaded to a Chinese Milestone developers' BBS.
But there is a simple question which still confused me a lot. (- =)
Some senior developers in that Chinese BBS reminded their supporters in their threads to wipe before and AFTER applying the Rom in Open Recovery. But, why should we wipe AFTER applying the Rom? I've viewed some threads here, but none of them require to wipe after applying.
So I wonder if it is really necessary to wipe AFTER applying a new ROM. I'm very appreciate if you guys can answer my question and tell me why. Thx~~~
BTW, Xda is an excellent website. And it's much more professional than the BBS I used to visit. May you have a nice day~
It's a common myth. I'm not sure why it gets repeated over and over again.
One wipe is enough. Dalvik-cache is not populated again until the system is booting for the first time. While you are in recovery, it also doesn't matter if you wipe before or after you apply the update (unless the updater script in some particular update.zip also installs something to /data or /cache partition, which is not very common).
You can read cvpcs's thoughts on this matter here: http://cvpcs.org/blog/2011-06-05/time_to_wipe_data/cache
kabaldan said:
It's a common myth. I'm not sure why it gets repeated over and over again.
One wipe is enough. Dalvik-cache is not populated again until the system is booting for the first time. While you are in recovery, it also doesn't matter if you wipe before or after you apply the update (unless the updater script in some particular update.zip also installs something to /data or /cache partition, which is not very common).
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Click to collapse
Thanks a lot~ (I'm looking for some threads which can explain how "wipe" works. Actually I still got some problem about that, like " Why system app still maintain after wipe? Is it because those system app has a backup in Flash Memory, and it will restore after wipe the EEPROM?")
(This message is only for testing whether it is reply to the original poster or the people who answer it....)
[E]Xtreme said:
Thanks a lot~ (I'm looking for some threads which can explain how "wipe" works. Actually I still got some problem about that, like " Why system app still maintain after wipe? Is it because those system app has a backup in Flash Memory, and it will restore after wipe the EEPROM?")
Click to expand...
Click to collapse
System apps are installed into a different partition (/system), which also holds the OS files. Wiping data and cache only wipes the /data and /cache partitions and leaves /system alone. Otherwise the phone wouldn't work at all.
Dave Lister said:
System apps are installed into a different partition (/system), which also holds the OS files. Wiping data and cache only wipes the /data and /cache partitions and leaves /system alone. Otherwise the phone wouldn't work at all.
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Got it~ That's very kind of you.
Related
I want to do a full wipe of all data when going from ROM to ROM installing to EMMC.
So far each time I install, some files are left over in one or other area.
I have yet to find a complete answer/quide on how to go about completely cleaning everything before installing a new ROM?
(Ideally the equivalent of formating and partitioning before installing Windows...)
At the moment I am cautious to try the WIPES and FACTORY RESET options in CWM as I have not found a solid answer as to what they do here.
(Is CWM the way to go here?)
Thanks for any help
There is utility like that for GTAB but didn't see one for NC
http://forum.xda-developers.com/showthread.php?t=974422
And in this post all the way down in OP:
http://forum.xda-developers.com/showthread.php?t=985705
Let me see if I understand this correctly, you're saying you manually format each partition under CWR and are sketched about using the factory reset function? Ive both wiped and flashed between various emmc based roms as well as EXT4 based roms to the (EXT2?) based roms without a problem. Each time I use the correct CWR and manually format /system, /data, and /cache. If i'm understanding your question correctly then I hope this helps. It may not be the fix you're looking for but it works.
stevencpoynter said:
Let me see if I understand this correctly, you're saying you manually format each partition under CWR and are sketched about using the factory reset function? Ive both wiped and flashed between various emmc based roms as well as EXT4 based roms to the (EXT2?) based roms without a problem. Each time I use the correct CWR and manually format /system, /data, and /cache. If i'm understanding your question correctly then I hope this helps. It may not be the fix you're looking for but it works.
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Click to collapse
yeah - thanks, i think that is pretty much what i am after.
What is the difference between factory reset/wipe and formating the system/data partitions?
Is there anything on the boot partition that might get left over?
I am using MIUI 5.31 at the moment.
However it was known to be there'll be some update today after.
Is there any way to back-up and restore on the new version of ROM?
I have backuped all the systems and applications using the back-up menu.
Do I simply get new 5.32 and restore using the backup i created just now?
And to install a new version, from my old version 5.31, do I have to do
format /system
format /cache
format /data
and then install from SD card?
(or do I have to go back to Froyo? hopefully not )
And final question! Everytime I update the ROM, do i have to re-calibrate the battery? (Make battery full and wipe-out the battery status)
Thanks in advance! have a good day
um im newbie too so don't trust me too much
for updating existing rom.. do not require back-up and stuff..
u just /format system and cache and install the new Rom using CWM
it does not wipe out anything everything stays same except the rom version
hope this helps
Oh yeah and I wanted to ask question for calibration thing so.. if anyone have answer plz post XD
what does format /datadata do exactly? that in comparison with format /data
candoo100 said:
um im newbie too so don't trust me too much
for updating existing rom.. do not require back-up and stuff..
u just /format system and cache and install the new Rom using CWM
it does not wipe out anything everything stays same except the rom version
hope this helps
Oh yeah and I wanted to ask question for calibration thing so.. if anyone have answer plz post XD
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Click to collapse
Thanks! Now I have some ideas how to do it. I will try your way first. But don't we need to format / data aswell?
I'm also getting confused between format /data and format /datadata. ><
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Feelosopher said:
Thanks! Now I have some ideas how to do it. I will try your way first. But don't we need to format / data aswell?
I'm also getting confused between format /data and format /datadata. ><
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Click to expand...
Click to collapse
If you want to do a completely clean install, format cache, system, data and datadata. If you want to keep your apps etc, format system and cache. Hope that clears things up
Shrapnel2 said:
If you want to do a completely clean install, format cache, system, data and datadata. If you want to keep your apps etc, format system and cache. Hope that clears things up
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^^ yeah thats the best way, u dont need to format /data everytime, only when you feel like a clean install.
as for battery calibration, this is not needed for upgrades. usually a battery calibration is required when a full firmware is flashed with ODIN.
And MIUI backup will allow you to restore backups on older / newer versions of MIUI, but as mentioned above, you dont need to backup unless you are going to format /data and /datadata - where apps are stored
Shrapnel2 said:
If you want to do a completely clean install, format cache, system, data and datadata. If you want to keep your apps etc, format system and cache. Hope that clears things up
Click to expand...
Click to collapse
yeah, just format cache and dalvik cache if want to maintain your apps!
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wow! thanks for the answers guys. It really helped me out to understand it more!!
I'll try out the new rom now. Thanks again!
Hi all
I would like to know all about updating CM7. Currently I have 7.1.5 installed, I Have an ext3 (or ext2) partition for A2SD.
How now would I go about updating to a more recent release? On MIUI it was simply just wiping the cache & the dalvik cache.
Please can someone assist with a slightly detailed answer (I don't find very consistent results).
Also, let's say I'd like to do a clean flash of CyanogenMod (assuming that's not what's required in the first place), but I don't want to format my ext3 partition but simply keep the apps on the fresh rom - how would I do that? Or should I ask what I should be backing up and restoring? If it's not too "clean" to do it like this, please let me know.
Any and all information is welcome. I'd just like to have a clear picture on what I'm dealing with.
Thanks.
Sent from my Milestone using XDA
d.casper.b said:
Hi all
I would like to know all about updating CM7. Currently I have 7.1.5 installed, I Have an ext3 (or ext2) partition for A2SD.
How now would I go about updating to a more recent release? On MIUI it was simply just wiping the cache & the dalvik cache.
Please can someone assist with a slightly detailed answer (I don't find very consistent results).
Also, let's say I'd like to do a clean flash of CyanogenMod (assuming that's not what's required in the first place), but I don't want to format my ext3 partition but simply keep the apps on the fresh rom - how would I do that? Or should I ask what I should be backing up and restoring? If it's not too "clean" to do it like this, please let me know.
Any and all information is welcome. I'd just like to have a clear picture on what I'm dealing with.
Thanks.
Sent from my Milestone using XDA
Click to expand...
Click to collapse
Upgrades: Just erase dalvik and cache and apply update
Clean Install: Erase everything. Ext partitions are not affected by the format. Only thing is that it will erase your app data (games saves, etc). The actual apps will be left in tact though.
Definitely recommend a clean install if your coming from 7.1.5. Good luck!
Just wanted to know what happens when you format /system and /preload partitions.
Suppose you format /system from recovery. Can you boot into you ROM after that? Or is that where the ROM was?
dark_polok said:
Just wanted to know what happens when you format /system and /preload partitions.
Suppose you format /system from recovery. Can you boot into you ROM after that? Or is that where the ROM was?
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Click to collapse
If you format /system in recovery you blow away the ROM, definitely cannot boot after that. If you format /data as well, the only way you'll be able to recover is with an ADB sideload.
you_eeeeeediot said:
If you format /system in recovery you blow away the ROM, definitely cannot boot after that. If you format /data as well, the only way you'll be able to recover is with an ADB sideload.
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Thanks.
What if I format /system + /data + cache and dalvik chache and then flash a custom rom right after that, without rebooting the phone in any way [meaning not rebooting into system or bootloader or recovery] that should be ok right? Coz I came from a S3 and that combination worked perfectly for it.
Also still have no idea what the /preload partition and formatting it does.
That's what I do when I update within a rom.
Wipe system, cache, dalvik. Flash rom, then wipe cache/dalvik again.
Just a habit after all the different recommendations from previous devs in the past.
dark_polok said:
Thanks.
What if I format /system + /data + cache and dalvik chache and then flash a custom rom right after that, without rebooting the phone in any way [meaning not rebooting into system or bootloader or recovery] that should be ok right? Coz I came from a S3 and that combination worked perfectly for it.
Also still have no idea what the /preload partition and formatting it does.
Click to expand...
Click to collapse
Yes you can wipe /system, /data and /cache and you're good to flash a ROM, no need to reboot back into recovery again. Dalvik-cache is located on /data, so no need to wipe dalvik when you're wiping data, it's redundant. There is no need to worry about wiping or formatting /preload in almost all situations, otherwise the ROM devs would be telling us to do it. Back in my Galaxy s3 days I remember some ROMs would wipe and flash /preload but I don't think it's a big deal on the One. If it needs to be done, the ROM installation script will handle it.
Most ROM installation scripts wipe /system so it usually isn't necessary to do it yourself. However I do it anyway just to insure a completely clean installation in case the dev's script is messed up (it does happen). Wiping /data is optional of course but it is recommended when changing the base version (for example, 4.1.2 to 4.2.2) or if you're anal like me you can wipe data when upgrading between HTC base versions (2.17 to 2.24 for instance). Some people don't ever wipe /data and don't have any problems, but I can guarantee many of the weird odd-ball issues on this forum could have been prevented with a full wipe.
erikikaz said:
That's what I do when I update within a rom.
Wipe system, cache, dalvik. Flash rom, then wipe cache/dalvik again.
Just a habit after all the different recommendations from previous devs in the past.
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Click to collapse
henrybravo said:
Yes you can wipe /system, /data and /cache and you're good to flash a ROM, no need to reboot back into recovery again. Dalvik-cache is located on /data, so no need to wipe dalvik when you're wiping data, it's redundant. There is no need to worry about wiping or formatting /preload in almost all situations, otherwise the ROM devs would be telling us to do it. Back in my Galaxy s3 days I remember some ROMs would wipe and flash /preload but I don't think it's a big deal on the One. If it needs to be done, the ROM installation script will handle it.
Most ROM installation scripts wipe /system so it usually isn't necessary to do it yourself. However I do it anyway just to insure a completely clean installation in case the dev's script is messed up (it does happen). Wiping /data is optional of course but it is recommended when changing the base version (for example, 4.1.2 to 4.2.2) or if you're anal like me you can wipe data when upgrading between HTC base versions (2.17 to 2.24 for instance). Some people don't ever wipe /data and don't have any problems, but I can guarantee many of the weird odd-ball issues on this forum could have been prevented with a full wipe.
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Click to collapse
Very helpful replies guys. Thanks =}
I'm getting ready to update my old ParanoidAndroid (with CWM v5.5.0.4) with the CarbonRom.
I've backed up all kinds of logs, settings, and data that I think I may want to restore with the new rom.
I've also made a CWM backup (although of course I hope not to use it).
My question is - should I format the system partition (from CWM, Mounts & Storage option) before flashing the new rom?
I've seen people say emphatically that to get a clean install you need to do this.
Yet I've seen other's write just as insistently that you should NOT format the system partition. Do they say this because it is too dangerous? If I format the system partition and then for some reason the new rom won't load, does that mean my CWM is wiped out, making it difficult to recover?
I think I do want the system format because I don't want a bunch of old files hanging around ... but I want to make sure this is not too dangerous.
I've also seen others who recommended also formating the boot partition. Is there any value in that? Sounds even more dangerous ... no?
~Paul
pmennen said:
I'm getting ready to update my old ParanoidAndroid (with CWM v5.5.0.4) with the CarbonRom.
I've backed up all kinds of logs, settings, and data that I think I may want to restore with the new rom.
I've also made a CWM backup (although of course I hope not to use it).
My question is - should I format the system partition (from CWM, Mounts & Storage option) before flashing the new rom?
I've seen people say emphatically that to get a clean install you need to do this.
Yet I've seen other's write just as insistently that you should NOT format the system partition. Do they say this because it is too dangerous? If I format the system partition and then for some reason the new rom won't load, does that mean my CWM is wiped out, making it difficult to recover?
I think I do want the system format because I don't want a bunch of old files hanging around ... but I want to make sure this is not too dangerous.
I've also seen others who recommended also formating the boot partition. Is there any value in that? Sounds even more dangerous ... no?
~Paul
Click to expand...
Click to collapse
You can format system,data, internal storage and cache without any worries if you are on PA rom read install instructions in carbon rom thread after or before.
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