Problem partitioning SD card

I'm trying to create a second partition on the SD card in my phone. I'm using Minitool Partition and the newest version doesn't even detect the SD card and an older version detects it but when I go to resize and click "apply changes" it gives me an I/O error. How can I fix this? Would reformatting the SD card completely help?

For some reason when I make a second partition (regardless of it's type) the phone says there is no SD card but as soon as I delete the second partition the phone picks up the SD card and all my data I had saved on it is still there. What is going on?

Do you know for sure the phone is designed to handle multiple partitions?

According to step 4 of this guide written for the phone, yes.

Hmm, in that case I only have two idea's:

1. Maybe an issue with that specific SD card, perhaps you could try a different SD card.
2. The phone may need to be powered off and back on, to pickup on the partition changes.

I have never partitions an SD card, nor do I have the phone you are trying to optimize. Wish I could help further but my knowledge is very limited, where phones are involved.

Like to ask WHY bother? Images, Videos and Music already be in separate folders.

There is little internal memory on the phone that apps can be installed on. Link2SD is an app that copies apps from the phone on to the SD card and creates a symbolic link to them so the apps are as if they are on the phones memory (I don't know why apps can't just normally be placed onto the SD card). Link2SD requires a second partition on the SD card, I don't know why it can't use the partition already there and still make a symbolic link. This is my understanding, may be flawed.

I think it may be 1, it seems to work for others. I posted the question here on the Xperia Arc sub-forum. Thanks!

I figured it out!!! I needed to make the second partition "primary" too. How is it possible to have two partitions on the same device primary?

You are allowed up to 4 primary partitions per device. One of the 4 can be made an extended partition which can house a dozen or more logical partitions.

Anyway, I'm glad you got it worked out. I never suspected the second partition needed to be primary. I guess I was assuming, you were creating primary partitions all along.