RuneAudio Partition layout on SD card

Samsonite801

I am just curious..

So I wanted to see how the partitions are being used (with fdisk) on the RuneAudio image:

-----------------------------------------------------------------------------------------------
Disk /dev/mmcblk0: 29.8 GiB, 32010928128 bytes, 62521344 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x00005f47

Device Boot Start End Sectors Size Id Type
/dev/mmcblk0p1 2048 206847 204800 100M c W95 FAT32 (LBA)
/dev/mmcblk0p2 206848 4401151 4194304 2G 83 Linux
-----------------------------------------------------------------------------------------------

I see that most of my space from the SD is unallocated..

So what I was pondering about at first, as I start playing with RPi is the SD card life concept, and one of my potential paths was to do DIY and convert everything over to RAM disk, and read-only root (while in normal operation), and could use remount rw to save stuff back, etc.. And of course Frank mentioned about potential for using the arch-linux version at some point, as it has means to minimize SD card writes.

Well that was last week's thought (however, may still take one of those paths in the long run as I play around).

This week I had been pondering about how the lifespan would be to use a very large SD card, as it would take advantage of the flash 'wear leveling' concept, so I ran the above to check the layout: fdisk /dev/mmcblk0 ...to get an idea about if I can take advantage of wear leveling and notice that most of the space is unallocated.

So I was wondering, does the wear leveling use any given cell on the flash to make writes, regardless of the partition layout? I know on traditional SSD drives this is the case (all partitions are virtualized), but just wondering if this is also the case with SD card flash since they may not have as complex of a logic controller chip.

Any thoughts on this?

hondagx35

/dev/mmcblk0p1 2048 206847 204800 100M c W95 FAT32 (LBA)
/dev/mmcblk0p2 206848 4401151 4194304 2G 83 Linux

This is made this way because the image should fit on a 2GB SD card.
It's easy to expand the SD card to full size.

So I was wondering, does the wear leveling use any given cell on the flash to make writes, regardless of the partition layout?

I also do not think that this is the case.

Frank

Samsonite801

Hey, thanks for sharing that. I think yeah, for now I will grow the partition for RuneAudio and the wear leveling will probably be fine for the most practical use..

The good news is it is a simple OS, in that it does not require much time to deploy and set up, it also easy to take a config file backup, or even a full SD card img backup once in awhile so not a super big deal if the card decides to crash. The loss would not be huge since redeploy is simple.

But I do have other RPi implementations where I worry more about backing things up because it took hours to get them set up a certain way.

RuneAudio is very nice in that regard.. Simple, and it just 'works' right out of the box.. I set another RPi up last night with RuneAudio in less than 1/2 hour.. (to the point where it is ready to play music.

pelliott321

Is there a simple procedure to clone the bootable SD chip as a backup?

betocool

This answer here does the trick fine:

http://raspberrypi.stackexchange.com/questions/311/how-do-i-backup-my-raspberry-pi

Just create an image of your SD Card on another drive, and re-flash it back in case it crashes.