Talk:Secure Digital card

See article on proper SD card insertion here:

http://wiki.laptop.org/go/Secure_Digital_card

I'm getting frustrated with my XO.. here is the error message:

(the sd card works in my laptop, and an sd card from another guy that worked in his xo didn't work in mine) I did dmsg | grep mmc > errorfile.txt and copied it over to the pc via usb stick

[ 4138.954421] PM: Adding info for mmc:mmc0:e624
[ 4138.956336] mmcblk0: mmc0:e624 SD128 123008KiB (ro)
[ 4138.956509]  mmcblk0:<3>mmcblk0: error 1 transferring data
[ 4139.306260] end_request: I/O error, dev mmcblk0, sector 0
[ 4139.306291] Buffer I/O error on device mmcblk0, logical block 0
[ 4139.655996] mmcblk0: error 1 transferring data
[ 4139.656028] end_request: I/O error, dev mmcblk0, sector 0
[ 4139.656054] Buffer I/O error on device mmcblk0, logical block 0
[ 4140.229291] mmcblk0: error 1 transferring data
[ 4140.229326] end_request: I/O error, dev mmcblk0, sector 245888
[ 4140.229355] Buffer I/O error on device mmcblk0, logical block 30736
[ 4140.579771] mmcblk0: error 1 transferring data
[ 4140.579806] end_request: I/O error, dev mmcblk0, sector 245888
[ 4140.579834] Buffer I/O error on device mmcblk0, logical block 30736
[ 4140.930396] mmcblk0: error 1 transferring data
[ 4140.930429] end_request: I/O error, dev mmcblk0, sector 245888
[ 4140.930457] Buffer I/O error on device mmcblk0, logical block 30736
[ 4141.280933] mmcblk0: error 1 transferring data
[ 4141.280966] end_request: I/O error, dev mmcblk0, sector 0
[ 4141.280992] Buffer I/O error on device mmcblk0, logical block 0
[ 4141.631323] mmcblk0: error 1 transferring data
[ 4141.631355] end_request: I/O error, dev mmcblk0, sector 0
[ 4141.631381] Buffer I/O error on device mmcblk0, logical block 0
[ 4141.981813] mmcblk0: error 1 transferring data
[ 4141.981844] end_request: I/O error, dev mmcblk0, sector 0
[ 4141.981869] Buffer I/O error on device mmcblk0, logical block 0
[ 4142.332291] mmcblk0: error 1 transferring data
[ 4142.332326] end_request: I/O error, dev mmcblk0, sector 246008
[ 4142.332354] Buffer I/O error on device mmcblk0, logical block 30751
[ 4142.682949] mmcblk0: error 1 transferring data
[ 4142.682984] end_request: I/O error, dev mmcblk0, sector 246008
[ 4142.683012] Buffer I/O error on device mmcblk0, logical block 30751
[ 4143.033572] mmcblk0: error 1 transferring data
[ 4143.033604] end_request: I/O error, dev mmcblk0, sector 246008
[ 4143.383828] mmcblk0: error 1 transferring data
[ 4143.383860] end_request: I/O error, dev mmcblk0, sector 246008
[ 4143.734087] mmcblk0: error 1 transferring data
[ 4143.734120] end_request: I/O error, dev mmcblk0, sector 246008
[ 4144.084380] mmcblk0: error 1 transferring data
[ 4144.084412] end_request: I/O error, dev mmcblk0, sector 246008
[ 4144.434655] mmcblk0: error 1 transferring data
[ 4144.434689] end_request: I/O error, dev mmcblk0, sector 245952
[ 4144.434733] Buffer I/O error on device mmcblk0, logical block 30744
[ 4144.785359] mmcblk0: error 1 transferring data
[ 4144.785395] end_request: I/O error, dev mmcblk0, sector 246000
[ 4145.135698] mmcblk0: error 1 transferring data
[ 4145.135730] end_request: I/O error, dev mmcblk0, sector 246008
[ 4145.485982] mmcblk0: error 1 transferring data
[ 4145.486014] end_request: I/O error, dev mmcblk0, sector 246008
[ 4145.836244] mmcblk0: error 1 transferring data
[ 4145.836277] end_request: I/O error, dev mmcblk0, sector 0
[ 4146.186520] mmcblk0: error 1 transferring data
[ 4146.186551] end_request: I/O error, dev mmcblk0, sector 0
[ 4146.536808] mmcblk0: error 1 transferring data
[ 4146.536839] end_request: I/O error, dev mmcblk0, sector 0
[ 4146.887131] mmcblk0: error 1 transferring data
[ 4146.887164] end_request: I/O error, dev mmcblk0, sector 0
[ 4147.237470] mmcblk0: error 1 transferring data
[ 4147.237505] end_request: I/O error, dev mmcblk0, sector 0
[ 4147.599824] mmcblk0: error 1 transferring data
[ 4147.599858] end_request: I/O error, dev mmcblk0, sector 0
[ 4147.950240] mmcblk0: error 1 transferring data
[ 4147.950275] end_request: I/O error, dev mmcblk0, sector 0
[ 4148.300574] mmcblk0: error 1 transferring data
[ 4148.300606] end_request: I/O error, dev mmcblk0, sector 0
[ 4148.653739] mmcblk0: error 1 transferring data
[ 4148.653772] end_request: I/O error, dev mmcblk0, sector 0
[ 4149.004063] mmcblk0: error 1 transferring data
[ 4149.004093] end_request: I/O error, dev mmcblk0, sector 0
[ 4149.354300] mmcblk0: error 1 transferring data
[ 4149.354329] end_request: I/O error, dev mmcblk0, sector 0
[ 4149.354371] Buffer I/O error on device mmcblk0, logical block 0
[ 4149.704905] mmcblk0: error 1 transferring data
[ 4149.704940] end_request: I/O error, dev mmcblk0, sector 0
[ 4150.055248] mmcblk0: error 1 transferring data
[ 4150.055282] end_request: I/O error, dev mmcblk0, sector 0

High capacity 8GB SD card did not work

This was a cheapo card by PQI. It's a long story, but after several days, the results are:

formatted as ext2 (because I was trying to use it for an alternate OS (debian), the XO would initially be able to read the directories, but then lose track and give various error messages. directories unreadable, unwritable, non-existent, card has bad blocks or bad superblock, and so on.

after much messing about, during which I got clever and tried to have 2 partitions, the card's partition table became corrupted, and I suddenly had a 5.6GB card! While trying to troubleshoot this, from what I saw on the web, I was lucky I didn't lose the whole thing. There is, apparently, absolutely no fix, although some manufacturers have ways of reformatting it for you. (Not PQI) Moral: do not mess about.

(Just to be clear, there was nothing initially wrong with the card, either when it had 2 4GB partitions, one ext2, one FAT32, or when it had a single, low-level reformatted 5.6GB partition. My Ubuntu system read and wrote to it repeatedly without problems.)

I hope this gets fixed in a future build. It would be wonderfully elegant to have one's alternate OS, plus any added programs, on a roomy high capacity card. Right now I've had to put everything on the poor XO, which has all of 100MB out of its one gigabyte left.  :-(

If the card has actually lost capacity, then the card is purely to blame. Perhaps it ran out of replacement sectors, then decided you'd prefer a 5.6GB card over an 8GB read-only card. Perhaps the card's built-in software has bugs, likely involving corruption of internal structure when power is unexpectedly lost. (sigh... the crummy manufacturers have created a head crash equivalent for flash media, showing clear disrespect for the integrity of our data)

Intermittent mount

I have inserted an SD card. Sometimes it shows up, sometimes it does not. This goes for both the journal and from the shell.

Also, I don't seem to be able to eject it. I've stopped short of prying it out with a screwdiver or tweezer.

Any tips?

Ericvh 19:07, 8 January 2008 (EST)

If you need to get the card out, tweezers are probably the way to go. The slot has a flap that keeps out moisture and dust when there is no card present, but it makes it inserting and removing the card difficult; the slot seems to be intended more for a semi-permanent storage upgrade than for removable media. As for the intermittent behavior, perhaps the card is not firmly seated? —Joe 19:49, 8 January 2008 (EST)

Try Pushing it in and release - It has a click-in to load and click-in to eject spring loaded mechanism. Once it is clicked out, it will jut out enough for you to pull it out with just your fingers - UNLESS you are using a non-standard card which is thicker than the slot opening, in which case back to tweezers.

Ram, [Boston, MA] 10 January 2008 (EST)

Transfer Rate

I see that SD cards are being manufactured in different speeds -- 45x, 150x -- for high-pixel cameras and such. What is the maximum transfer rate the OLPC will benefit from?