Memory Expansion Doesn't Work Like I Expect

I'm not sure if something is wrong, or that's just the way things go.

I have a Linux Acer Aspire One and an 16GB SDHC card.

I put a few files on the SDHC card via my Windows PC (via a USB connection). If I slide the card in the SD card slot (upper right corner of the One), the card sticks out a bit, but it reads it perfectly. All the files I loaded are visible and accessible.

I unmount the same SDHC card and then put it in the Storage Expansion slot (lower left hand corner). It slides in snuggly (doesn't protrude) and the OS tells me that the storage has expanded by 16GB or so.

However, none of the files are visible. :cry:

Why is that?

If I remove the card and put it back in the other slot, then the files reappear.

Is this behavior normal?

I guess I don't understand how Storage Expansion works. Everyone raves about it, but it's not intuitive.

For example, if I load programs and files while an SDHC card is in the expansion slot, how do I know if the data is being saved there or in the internal storage?
Is there any way to access files on the card without resorting to swapping it with the other slot?

 

I think that the files are not visible because you have added to the storage, unlike the 5-1, where you are mounting the device to see the files.

To my understanding you should NOT be able to see any files on the card in the expansion slot, as you have added or "merged" the card to the SSD, to make one drive.

 

Thanks for the reply!

Given your answer, it seems that there's no easy workaround this issue. What I understand from your response is that The One looks at whatever free space there is in the Expansion Slot and claims it for general use. It ignores the rest (in this case, my files). It just blocks them out.

It still leaves me with a related mystery. Let's say I save a 3GB file in the merged memory. If I pop out the card, will I be able to access that file from a PC or will I never know if part of the file is on the SD card and part of it is in the internal memory?

 

There is no workaround, the expansion slot is doing exactly what is it supposed to do. It is not a reader, it adds the TOTAL volume of the SDHC card to the internal SSD volume to make one virtual drive.

If there are files on the SDHC when it goes in the expansion slot, they are not meant to be seen, as it is NOT a reader. In fact, they will be overwritten in time as the data begins to be written to the card. If you want to see and use the files on the SDHC, that is what the other slot is for.

 

Are you sure those files aren't there?

When I do it I see all the files on the card whether I put it in the left or right slot, in fact I regularly take my SDHC card out of the left slot change my selection of music in the Music folder of the card on my desktop machine and put it back in my AA1 and they go back into the merged filesystem just fine.

And contrary to what Gutty96 says, the left slot is just another reader and the merging is done using Aufs to combine the contents of the filesystem on the card with the contents of /home/user into a virtual filesystem at /mnt/home.

 

The reason the files aren't visible is that i believe the expansion card is formatted in ext2/ext3 or another linux-only filesystem.
EXT2IFS from http://www.fs-driver.org should help you read it (on Windows XP, vista is flaky)

And the expansion slot IS a reader. How else would it read the data?

 

Ask three different people, get three different answers! :lol:

DHowett: I didn't do any special formatting with the 16GB SDHC card. I just plugged it in and it started working.
Besides, if the formatting impeded the OS from seeing the files, why does it see them on the right hand reader and not on the left hand reader? Is there a way to format it so that it's read by both readers equally?

Gutty wrote:

I think that's wrong. I put 2.3 GB of data on the card and the total available virtual memory on the card, according to the Storage Expansion slot shrank by 2.3 GB. Although I couldn't access the data, the virtual memory knows it's there and (presumably) prevents me from overwriting it (otherwise, it would say that there's an extra 2.3GB of space available.

Retsaw: Do you know what you did to be able to read each card on either port? What size of card is it? I vaguely remember reading that the max card size it can handle was either 4 or 8 GB. Which is strange since it can read my 16GB card.

Still confused. :roll:

 

It is an 8GB card, not that it should make a difference, there shouldn't be a size limit on the expansion with the setup being used. The only size limit should from what the reader + driver can actually read. I didn't do anything special to get it to work, though I have disabled auto-mounting in Thunar because it annoys me, I don't know if that affects it at all.

Is the storage expansion actually working in your case, I read somewhere else on these forums that Thunar was still adding the disk space from the card to the total storage even after aufs had been disabled and the storage wasn't being combined.

There are three relevant directories with files in, your home directory at /home/user/, your SD card probably at /media/disk/ but it could be different and the combined /mnt/home. Perhaps you should check all of these (maybe in the terminal if you are comfortable with that) and see what files show up, you should certainly see your files in /media/disk, and if you don't see them in /mnt/home/ I think the most likely explanation is that the space isn't being combined for some reason.

 

Retsaw: You are a genius! :ugeek:

I put my SD card in the Storage Expansion slot (where I normally can't see the files like I can in the right hand slot). As usual, I couldn't see how. However, in the address bar of Thunar (aka File Manager) I typed:

/media

Or

Removable:///disk

Suddenly I could see those files that have eluded me for so long.

Although I don't fully understand why Acer implemented the memory management this way, I'm glad that I can access the SD files no matter which slot I put it in. (I have two 16GB cards.)

Thanks for your help!

 

Expansion is done by using the aufs filesystem, which creates a 'virtual' directory that is a combination of the files in the home directory of the SSDD and the files on the SDHC. I believe that only Thunar (the GUI file manager) is aware of the virtual drive, so other programs that you might use will have trouble finding the SDHC card. From a terminal, type 'df' and you'll see where the SDHC card is mounted.

Perry
www.kidpub.com

 

Of course, expansion of the SSD isn't really expansion at all because the additional space isn't seen or used by the main OS. You'll come up against this limitation when your boot SSD (the original 8Gb one installed in the Aspire One) gets full. For example, installation of new software fails with insufficient disc space errors and you have to free space on the boot drive to get round this. Knowing what to remove isn't straightforward because Thunar treats both discs as a single virtual drive and there's no intuitive way of knowing where files that can be safely deleted are! Removing files that are stored on the expansion card doesn't help and you have to understand the Linux directory tree before you can find some files you may have downloaded that end up on the expansion card . Thunar often misses them and you need to run a terminal shell to dig down and find them.......really useless if you ask me.

It's not a good idea to give users the impression that they can expand the 8Gb SSD using an SD card when in reality, they can't. To avoid confusion, the expansion card should only ever be treated as just that and not pseudo-integrated into the boot disc's directory tree. :x

 

I put my new adata SDHC 8GB Class6 in the Storage Expansion slot but it is not recognised by the file manager.

How do I get it to start working? (Does it need formatting, mounting etc? Some posts imply that this is all automatic.)

 

So for XP users with a hard drive, does the expansion slot just work as another card reader? that's all it does with my 1 gig SD card. Shows all my files as D:\

 

All 3 of my cards were plug and play - automatic.

Try a different card and/or try formatting it on another computer or on a camera which does formatting.

 

So my 1GB SD card from my camera is automatically added in the expansion slot.

I don't think I have anything else that reads SDHC. Does seem to be a format issue. Is there a menu based format / mount sequence?

 

Can't format / mount 8GB SDHC Card

Tried to format in a Samsung L730 Camera but the camera won't format the card.

How do I do this in linpus?

 

Hi
The default view of File Manager is the home directory where you see Desktop etc.
If you want to see your left side SD card in File Manager, select View then Side Pane and click on Tree. This should show the card as SD/MMC Drive.
If you mount a USB stick in any of the USB ports they will also appear in the file tree. The directory name for this card is /media/disk and if you open it you will see the home folders replicated. If you want to write data to the SD card, say Open Office files you need to select the /media/disk/documents. The last folder being the one you wish to hold the file in. If you want to say copy picture files from a USB stick it is exactly the same as you would in windows. COPY the file and PASTE into the Pictures folder. This can be done at Tree level or by the /media etc. route if you wish.
With regard to your later question about formatting, my card is Fat 32 and works OK. If you have a Windows PC you can format the card on that. My camera did not recognise the card. I am sure it worked without me having to format it.
First try what I said above and locate the card.

If you want a more detailed and technical description of how this card works with the SSD google macles.blogspot. He has a lot of very useful info on the Aspire One particularly the one about creating a Backup.

Best wishes

 

Re: Format SDHC Card under windows

I found this for formatting under windows using a card reader:

http://panasonic.jp/support/global/cs/s ... atter.html

I note some discussion that there are different formats on the cards and they are not all compatible. The panasonic site claims that the format is different to just formatting under an operating system. I expect the other changes mainly relate to increasing the capacity of the SD cards before the SDHC was released.

Has anyone seen anything equivalent under unix?

 

Hi ndirons

Any comments on my previous answer to your problem?

With regard to the Panasonic format utility I have used it on my SDHC card when I once tried to dual boot with Ubuntu and rather messed up the card. I could not format it on my XP PC or via my camera and even when attempting to do so it told me the card only had 3GB.
I downloaded Panasonic SDFormatter V2.0 and it was able to reformat the card to 16GB FAT. It is this card I am now using in the left slot and as I said previously works a treat.

What are you trying to achieve with the card?

Best wishes

 

This is the utility my link goes to isn't it?

I'm fairly confident that the card is DOA since I can't get anything to recognise it but I thought I'd try to format it before I mailed it back.

I am justy trying to increase the internal storage.