Sd Formating


I need access card from Windows, so I prefer EXT2/3 due to IFS driver availability. I'm just curious if EXT3 have some significant benefit against EXT2? IIRC it may be journaling, but I don't know if journaling have sense on Pandora. My opinion is that no, so I choice EXT2. Maybe I'm wrong, so I ask, anyone competent?
What about JFS (but I can't find any JFS MS Windows driver)?
 
Senor Quack said:
Fragmentation is a non-issue on flash media, because there is no penalty for seeks like a hard drive.
Well actually there is a penalty but it is not worth defragmentation IMO. The thing is that SD/MMC cards have two commands for both reading and writing - one reads/writes single block (512 bytes) and one reads/writes multiple blocks. Multiblock commands are faster due to less overhead both for computer<->card communication and for on card internal SD/MMC controller<->NAND flash. This is true especially for writing when the card can optimize NAND memory erasing/writing by merging more writes of smaller blocks into one. With single block commands card is busy after each command which slows things down and for writing this also may result in extra work done.

Still, most often the card is not so badly fragmented and occasional 'seek' does not hurt. Defragmentation itself may hurt more.

Also this penalty is always there for systems that do not use multiblock commands at all (like PalmOS and possibly others). Linux uses them quite effectively, even separate requests for data (dd bs=512 count=x ..) can be merged into one multiblock command.

Real world example here - for Nokia 770 enabling multiblock writing changed write speed from ~300KB/s to ~2MB/s.

As for filesystem choice - one can make more partitions. First (bigger?) one as FAT for media and other data files for easy interoperability and another one(s) as ext2/3 for linux filesystems.

I guess current pandora low level bootloader can boot higher level bootloader and linux kernel from FAT(16?) partition only so for having full system on card one needs two partitions too.
 
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peca said:
I'm just curious if EXT3 have some significant benefit against EXT2? IIRC it may be journaling, but I don't know if journaling have sense on Pandora.
With ext3 you don't need to care about doing fsck at boot time when device crashed previously. This is especially useful if the system has no e2fsck binary or startup scripts do not handle it or there is no keyboard (and framebuffer console) to interact with e2fsck - all true for Nokia internet tablets. Of course you can hack it to remount ro, do fsck -y and reboot in case filesystem was modified but using ext3 is much easier. I was using ext3 on 770 for years and did not notice performance difference between ext3 and 2 and my card did not die from excessive writes too.
 
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"As for filesystem choice - one can make more partitions. First (bigger?) one as FAT for media and other data files for easy interoperability and another one(s) as ext2/3 for linux filesystems."

"I guess current pandora low level bootloader can boot higher level bootloader and linux kernel from FAT(16?) partition only so for having full system on card one needs two partitions too."

so would I be able to set up something like this? will this work?

boot ext3/root
ntfs or fat32/home
ext3/swap

or would this work?

boot ext3/root
ext3/home
ext/swap
ntfs fat32/ for storage

<<total noob here
 
FAT/NTFS partition must be the first one, Windows does not see past the first partition on removable media (=cards). For swap you can use swap file, performance is same (since 2.4 kernel few years back). For /home FAT/NTFS is not very suitable due to missing unix permissons.
 
If you are not concerned about using your card with windows, there is a filesystem optimized for flash usage: JFFS2 (Journaled Flash FS 2). It tries to distribute writes to the entire flash drive so that some blocks don't die before others. If you wanna go for a more "standard" FS, I'll suggest ext2/3

ish420 said:
"As for filesystem choice - one can make more partitions. First (bigger?) one as FAT for media and other data files for easy interoperability and another one(s) as ext2/3 for linux filesystems."

"I guess current pandora low level bootloader can boot higher level bootloader and linux kernel from FAT(16?) partition only so for having full system on card one needs two partitions too."

so would I be able to set up something like this? will this work?

boot ext3/root
ntfs or fat32/home
ext3/swap

or would this work?

boot ext3/root
ext3/home
ext/swap
ntfs fat32/ for storage

<<total noob here
That shold be possible, you can do it with a partitioning tool. Qparted or gparted are good.
 
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ati said:
If you are not concerned about using your card with windows, there is a filesystem optimized for flash usage: JFFS2 (Journaled Flash FS 2).
Quite frequent misconception. jffs2 is NOT suitable for memory cards, they already hide raw flash memory behing block layer so jffs2 features are almost worthless here. Also if anyone would actually try before suggesting it to someone he would find it is pretty hard to make it running (you need to add mtd over block device emulation so there are 2 layers canceling each other). Also jffs2 is pretty bad/slow with media size over few hundreds of megabytes.

EDIT: explanation is also directly in jffs2 FAQ
http://www.linux-mtd.infradead.org/faq/jff...l#L_stick_jffs2
 
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QUOTE

That has nothing to do with the files system that is due harddrive manufacturers using bytes instead of bits for measuring the capacity (1 byte = 8 bits). Your hardrive is advertised as 60Gb but is actually 60000000000 bytes or 55.87935447692871 GB.

Edit: beaten!


no, thats not what I'm talking about:
windows really showed me that 5gb of the disc was taken...
just as if I had a dvd on it or something....
except for it was absolutly empty
 
Benjiro said:
There isn't a SSD manufacture that does not warn about using a defrager. Normal, a SSD, or flash card will try to spread the amount of writes over the entire card, to reduce wear & tear.
That's in fact what I was thinking about: flash cards don't write linearily (is that even a word?), but do what the card's firmware tells them.
 
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Crasherball said:
no, thats not what I'm talking about:
windows really showed me that 5gb of the disc was taken...
just as if I had a dvd on it or something....
except for it was absolutly empty
It said that there was 5GB used, or 55GB free? If the later, then it's already been explained above - A 60GB drive contains ~55GB of space.

Karel Jansens said:
Benjiro said:
There isn't a SSD manufacture that does not warn about using a defrager. Normal, a SSD, or flash card will try to spread the amount of writes over the entire card, to reduce wear & tear.
That's in fact what I was thinking about: flash cards don't write linearily (is that even a word?), but do what the card's firmware tells them.


All NAND devices work by using a physical block list which is mapped to the exact same blocks of memory on the card, and a logical block list which is given to the OS, or whatever is trying to access the card. The OS has no knowledge of the physical blocks, so just writes directly to the logical ones, which the card allocates a random physical block to every time a write operation is performed on a logical block.

So degragging a NAND-based device will just reduce the amount of erase/write cycles.
 
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Squidge said:
All NAND devices work by using a physical block list which is mapped to the exact same blocks of memory on the card, and a logical block list which is given to the OS, or whatever is trying to access the card.
Actually, to my knowledge, only SD cards do this. xD and MMC cards are direct access to the NAND flash and would benefit greatly from an FS with built in wear leveling. I wasn't able to find any info on how Sony MemoryStick handles it.
 
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fanoush said:
Maybe you mean SmartMedia, not MMC. MMC is same as SD in this regard. SmartMedia indeed is (or was) pure NAND device with no controller.


Actually, I thought I was thinking of MMC. I was under the impression that it was SD minus all fancy controller and stuff that made SD better, although now that I think about it, I have no idea why I thought that, so you're probably right. I apologize. (That's way more thinking than I'm used to.)
I had completely ignored SmartMedia for the sake of my post. Seriously, who uses SM cards these days? No one, that's who. According to Wiki, they were discontinued years ago. Dead format walking! :p
 
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WizardStan said:
Seriously, who uses SM cards these days? No one, that's who. According to Wiki, they were discontinued years ago. Dead format walking! :p
uh oh, don't let the GP32 crowd hear you say that. :lol: i have an almost new 128MB SmartMedia card jammed in an old mp3 player somewhere around here, but aside from that i haven't seen one in years.

i'm curious, has anyone here ever personally experienced a flash device going bad just from excessive use? this topic reminds me of the threads i read on BBSs years ago regarding accessing the NVRAM found in dial up modems. some people were downright paranoid about wearing out that NVRAM.
 
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WizardStan said:
Seriously, who uses SM cards these days? No one, that's who. According to Wiki, they were discontinued years ago. Dead format walking! :p
:eek: Blasphemy, I have 2 working GP32 Blu`s that i still use, And have 6 SMC`s that i use with them, Though i have recently gone over to XD cards via an SMC to XD card convertor, In addition to the standard SMC`s as they are pretty (expensive and) hard to find.

Trooper
 
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WizardStan said:
fanoush said:
Maybe you mean SmartMedia, not MMC. MMC is same as SD in this regard. SmartMedia indeed is (or was) pure NAND device with no controller.


Actually, I thought I was thinking of MMC. I was under the impression that it was SD minus all fancy controller and stuff that made SD better, although now that I think about it, I have no idea why I thought that, so you're probably right. I apologize. (That's way more thinking than I'm used to.)
I had completely ignored SmartMedia for the sake of my post. Seriously, who uses SM cards these days? No one, that's who. According to Wiki, they were discontinued years ago. Dead format walking! :p

I was told MMC is (mostly) SD without the DRM chippery. MMC was first, and MMC cards should work in every SD slot.
 
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Karel Jansens said:
WizardStan said:
fanoush said:
Maybe you mean SmartMedia, not MMC. MMC is same as SD in this regard. SmartMedia indeed is (or was) pure NAND device with no controller.


Actually, I thought I was thinking of MMC. I was under the impression that it was SD minus all fancy controller and stuff that made SD better, although now that I think about it, I have no idea why I thought that, so you're probably right. I apologize. (That's way more thinking than I'm used to.)
I had completely ignored SmartMedia for the sake of my post. Seriously, who uses SM cards these days? No one, that's who. According to Wiki, they were discontinued years ago. Dead format walking! :p

I was told MMC is (mostly) SD without the DRM chippery. MMC was first, and MMC cards should work in every SD slot.


BEWARE the same is NOT true of micro-MMC/SD. My mother has a phone with a microSD slot. I was in every shop in her local area of Spain looking for a MicroSD card for it and nothing turned up. Eventually I found a 512Mb Micro-MMC card so purchased it and it did not fit the phone.

True tale.
 
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PSyMastR said:
Crasherball said:
i recently formated a 60gb usbdrive with ext3

but it turned out to have only 55gb left after formatting...
5gb of it was kinda taken....eventhough the drive was empty (since i just formated it)

thats kinda sucky isnt it?
is this a ext3-general-"feature" to take a high percentage of discspace just for the filesystem?
You might expect 60gb to be 1024mb x 60 = 61440mb.

But... manufactures consider 1000mb to be their gig, which is only 60000mb. Wait, thats only about 1gb lost. Yeah... nevermind...
This happens to every storage you buy. Manufacturers always lie about the space size. 60 gig is usally 50 something, 250 gig end up being 237 something, never what you paid for.
 
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I would love to be able to use NTFS, and take advantage of the encryption and transparent compression. Are there any plans for this? I know there are drivers that work perfectly, as I was using them on my laptop before the charger broke.
 
WizardStan said:
Actually, to my knowledge, only SD cards do this. xD and MMC cards are direct access to the NAND flash and would benefit greatly from an FS with built in wear leveling. I wasn't able to find any info on how Sony MemoryStick handles it.
I could of worded it better, I agree.

Full size MMC == SD.
xD and SM are basically the same (raw NAND)

On MMC & SD, the L2P (logical to physical) translation is done on the cards controller.
xD and SM don't have a controller, but the L2P is still present, but in a driver. To determine what logical block points to what physical block, you have the read the OOB (out of band) data on each NAND page. This is not optional if you want the card to be compatible with a SM card reader.

For that reason, wear levelling is not required in the FS.
 
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