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On Thursday 06 Aug 2015 21:17:29 Alan McKinnon wrote: |
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> On 06/08/2015 18:18, Meino.Cramer@×××.de wrote: |
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> > Hi, |
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> > |
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> > for my tablet PC I used a used 32GB FAT32 formatted SDcard. The |
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> > formatting was already done by the manufacturer. |
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> > Then I screwed it up and had to do the partioning and formatting |
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> > myself again. "No big deal", I thought -- and was wrong. |
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> > Yes, the "thing" I got could be read and written. But it was |
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> > DAMN slow in comparison to the original formatting. |
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> > |
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> > I googled and found a description, which described exactly, |
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> > what I wanted: An optimal formatting for one big FAT32 partion. |
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> > I did it again ;) and: TADA! The speed was back. |
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> > LINK:http://zero1-st.blogspot.de/2012/05/formatting-fat32-volumes-larger-> > than.html |
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> > |
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> > Now I need the something identical but explained in a way |
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> > that it can be successfully applied to any partion layout |
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> > and any SDcard size. |
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> > Currently the new SDcard has 64GB (yes, the tablet eats that size |
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> > well :) and needs at least two partions: One FAT32 and one ext4. |
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> > May be that I need a different layout later. |
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> > |
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> > To what aspect and "logic" do I have to keep my eyes on, when |
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> > it comes partioning/formatting any SDcard size with any partion |
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> > layout and any filesystem? |
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> |
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> As I understand it, the most critical thing is to keep the FS block size |
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> aligned with the native block alignment of the device. |
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> |
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> Example: Using 4k blocks that start at 1k is obviously going to be a |
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> problem - writing one block of data to the FS will always involve |
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> writing two blocks to the physical device |
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|
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I was wondering similar questions regarding a 32G flash card I have. Using |
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fdisk to partition it the starting sector was automatically aligned with 2048 |
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as it fdisk has been improved to deal with 4KB sector drives. |
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|
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However, formatting it with mkfs.vfat I was none the wise if I should use the |
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'-s sectors-per-cluster' option or what to set it at. |
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Furthermore, how can I read the current cluster size off the flash card? Is |
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this appropriate? |
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|
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blockdev --getbsz /dev/sdb |
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4096 |
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|
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-- |
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Regards, |
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Mick |
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