Sd Card Question...


guilmon999 said:
i thought most games were less then two gigs because the either ran cartridges or CDs so why are people worrying and im taking a Computer Repair A+ certification and it all says FAT32 is 4gb isnt that because microsoft made it that way
What about raw DVDs, large homebrew games, archives with many games inside, data for advanced games (like that photo zooming game in the dev section) etc?

And yes, FAT32 is limited to 4 GB files because it uses 32-bit integers to store "extent" information. I really wonder why they chose to construct it like that... I mean, ext2 came into being around that time and not too much later, you could find file systems such as ext3, reiserfs, BFS etc so it really strikes me as odd that FAT32 only used 32-bit addresses and not 64-bit or 128-bit.
 
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Not sure why people want to move SDCards between the pandora and the computer when there are so much better ways of transferring data like USB and wireless, but whatever.

I'll be putting BtrFS in my cards with compress and ssd options as one volume. Which would be nice since I'll waste less space and increase read/write speed significantly due to it balancing reads and writes across the two cards.
 
Alec  said:
I'll be putting BtrFS in my cards with compress and ssd options as one volume. Which would be nice since I'll waste less space and increase read/write speed significantly due to it balancing reads and writes across the two cards.
You probably won't see any actual speed increase because of 1. compression taking up CPU time and 2. the memory bus not being able to cover both SD card slots at full IO simultaneously.

Also, even with btrfs in SSD mode, it'll still have a journal (and even snapshots and journal journals and journal checksums etc) so your SD cards will suffer greatly. I'd stay with ext2 if I were you, and connect an actual SSD with btrfs on it if I find the need for one.
 
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I don't understand the need to furiously get rid of journaling. It is a safety mechanism, and a damn good one for crashes, accidental ejects, etc...
I understand flash use can take a hit due to journaling to the point of halving its life, but lets be honest, it is the same case of overclocking the pandora: overclocking any cpu will reduce its lifetime, but it still will be thrown away due to negligence, obsolescence, or any other reason definitely no related to overclocking, same thing with flash. By the time it starts failing, there will be 128 gb unofficial SDHC cards for 10 € or better, we will be with our Pandoras 2 (or 3) with full blown support for SDXC, so you will end up updating the card anyway.

As for me I will probably stick with ext3 (with ordered, or at minimum write back journaling mode) since it is writable by ext2fsd and perhaps an additional partition with fat32 for those windows computers that I don't want (or can't) install this driver.

As an experiment, how many of you has seen an sd card die of writes?
Not by malfunction, any card with heavy use should last years.
 
How about Mac users? I don't want to have to go through a VM in order to access my SD cards.

- ext* is not available on the Mac. Yes, there's ext2fuse but the author doesn't recommend using it to mount volumes with write support and I'm not too keen on losing data due to an immature FS driver.
- NTFS is available and ntfs-3g is stable. However, I can't disable the journal.
- HFS+ is available under Linux and seems to work as long as the volume is set up to be non-journalling but I don't have any concrete data. Does anyone have experience with HFS+ under Linux?
- exFAT is not available on any decent OS.

It appears that non-journalling HFS+ is the way to go but does anyone have other insights?

Also, does anyone know whether UDF would be a good idea? It's a fairly decent file system and should be able to deal with wear leveling but I've never used it for a general-purpose volume.
 
Unless you're deliberately trying to avoid M$ things, or you really *do* have a need for individual files over 2Gb in size (and I could only imagine that being the case if you were attempting to use the Pandora for some pretty serious video editing) then there's really no reason NOT to use Fat32; it's the industry standard format for flash media, used by pretty much every device that uses SD cards.

If you use Fat32, then you will be able to plug your Pandora via USB into any Windows PC, or MacOS based system, and pretty much any Linux box (unless it's owned by some hardcore M$ hating Linux nut who's disables Fat32 support) and be able to transfer files.

If you have any of the ext file systems then you would need to take additonal steps to install support in the OS for Windows or Macs if you want to, say, copy a video file/picture/music file from your friends computer, or a work computer. Something which your friend may not be keen on you doing, and something which work may not allow.
 
dflemstr said:
Alec  said:
I'll be putting BtrFS in my cards with compress and ssd options as one volume. Which would be nice since I'll waste less space and increase read/write speed significantly due to it balancing reads and writes across the two cards.
You probably won't see any actual speed increase because of 1. compression taking up CPU time
Assuming I don't spend as much money on SD cards as the Pandora itself, the cards are going to be pretty slow. Sacrificing a few CPU cycles to produce less I/O may very well help out. Zlib compression is really not that resource-intensive.


dflemstr said:
and 2. the memory bus not being able to cover both SD card slots at full IO simultaneously.
That's a shame though.


dflemstr said:
Also, even with btrfs in SSD mode, it'll still have a journal (and even snapshots and journal journals and journal checksums etc) so your SD cards will suffer greatly.
You're dead wrong here because
1. BtrFS does not journal because it does not need to.
2. I'm not planning on making any snapshots, so it won't have any snapshots (and I think you are missing the concept of copy-on-write)


dflemstr said:
I'd stay with ext2 if I were you, and connect an actual SSD with btrfs on it if I find the need for one.
Actually, unless you need compatibility, there is no point in using ext2.

Ext4 is significantly faster and it can run in "No Journaling" mode.
 
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Alec  said:
Ext4 is significantly faster and it can run in "No Journaling" mode.

It's very interesting to hear your argument, even though I might not understand all the issues, I don't see any reason on the surface to use an outdated file system, if as you say, ext4 can run in non-journaling mode.

So if I have understood it correctly, we don't want a journaling file-system because it increases writes to the disk, and will wear it quicker?

Thank-you.
 
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If you only ever intend to use linux PCs with your Pandora, knock yourselves out with whatever bizarre FS you want. :p

I think the main argument for FAT32 is it just works.
 
Aninhumer said:
If you only ever intend to use linux PCs with your Pandora, knock yourselves out with whatever bizarre FS you want. :p

I think the main argument for FAT32 is it just works.

I understand that argument too. However I think it's easier to reach that 4GB file size limit, than you think. In the age of DVDs and images. I suppose your ROMs won't be that large though, if Dreamcast only used a 1GB GDROM.

Did the GP2X use FAT32?
 
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Dead1nside said:
Alec  said:
Ext4 is significantly faster and it can run in "No Journaling" mode.

It's very interesting to hear your argument, even though I might not understand all the issues, I don't see any reason on the surface to use an outdated file system, if as you say, ext4 can run in non-journaling mode.

So if I have understood it correctly, we don't want a journaling file-system because it increases writes to the disk, and will wear it quicker?

Thank-you.

That's correct. It's possible that people just don't know about this since the No Journaling mode was introduced after Ext4's initial debut.
 
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Just a thought... but when it comes to NTFS formatted drives wouldn't this more or less fix the problem?
Code:
fsutil usn deletejournal /d

I know it removes the journal from NTFS drives when used in windows, but I can't say whether or not NTFS-3g would add a new one upon first access.

As to reasons to use it over FAT32, my sandisk 8GB usb drive with NTFS has a write speed that is fully twice the FAT32 rate. That could be more related to the NTFS vs FAT access in XP64 though.
 
BackAssward said:
Prometheus said:
Regarding FAT32, I'm a little surprised that nobody has mentioned this sort of thing yet. (I suppose someone has now. :p )
You should do a search, that came up quite a while ago.
I know it did, I remember a fair few things being said at the time. I meant in this thread specifically. ;)

To clarify why I felt it was worth mentioning (though to be honest I'm sure you know already - it's purely for clarity's sake :lol: ), it's due to the FAT32 legal actions such as that one.
 
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Blue Ion said:
As an experiment, how many of you has seen an sd card die of writes?
Not by malfunction, any card with heavy use should last years.

I killed a 32mb MS Pro Duo in my PSP days from developing an app that wrote to the card too many times.
 
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I just experimented with UDF 2.60. Windows XP SP3 can't read it (but should be able to handle UDF 1.50 and possibly 2.01); Vista likes it. The only problem is, though, that for some reason mounting a UDF-formatted USB mass storage device seems to confuse OS X's USB and block device management stacks to the point where Disk Utility becomes nonfunctional and System Profiler can neither enumerate USB devices nor SATA disks without hanging.

I've reported the hangs to Apple and will stick to NTFS now (FAT32 if I don't expect to use large files).
 
For those who want to use ext2 on windows: http://www.fs-driver.org/ . Works on vista and windows 7 x64 too.
EDIT: Support for ext3 as well.
 
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