Overprovisioning A Flash Drive ?

@bodhi, that makes sense. So basically fsck.f2fs isn't in initramfs, so therefore it needs to mount rootfs before it can fsck and linux doesn't like fsck'ing mounted partitions ... bit of a catch 22 there ! ... simple solution turn off the fsck, which does leave the partition open to becoming corrupt and unbootable !

My research also said that grub2 won't touch an f2fs partition, so in mainstream 'x86 linux world it's not possible to boot/rootfs off a single f2fs partition either.

Presumably later kernel and distro releases (+grub +uboot) will include f2fs support ... or not ! :D

Thanks for your help ... bottom line I feel for now for simplicity is probably boot and rootfs off of a ext2/3/4 partition, and if one wants to use f2fs then make a separate data partition and use it for that.

Cheers

Don Charisma ... because anything is possible with Charisma

My blog - http://DonCharisma.org
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Don,

I got a good deal from a surplus site for 2 GB industrial compact flash with built-in EDC/ECC, wear-leveling and block management from advantech. I am using that with CF usb reader as a EXT2 boot drive for DLNA/MPD renderer. I am relying on the hardware to keep my data and it has been running 24x7 for last three years. BTW Does anybody know if ZFS is supported on our Dockstar Debian? I cannot find anything. I want to boot with flash but store data on a ZFS hard disc.

metric,

> BTW Does anybody know
> if ZFS is supported on our Dockstar Debian? I
> cannot find anything. I want to boot with flash
> but store data on a ZFS hard disc.

No, it is not supported. ZFS takes too much memory to run (> 1GB), so I have given up on compiling it for ARM. Soon it'll be revisited given there are quite a few ARM boards now begin to support >= 1GB RAM. But on Dockstar, don't know if it can ever run ZFS.

-bodhi
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@metric thanks for the info ... it's better when it's taken care of in hardware ! ... and yes some ultra-cheap industrial grade media, I'd like that too :D

bodhi beat me too it on ZFS, my research indicated it needs a lot of memory, more for RAID5/6 (6-8GB recommended by freeNAS ) ... if I recall correctly ... but maybe some factors have changed !

Cheers

Don Charisma ... because anything is possible with Charisma

My blog - http://DonCharisma.org
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@Don,

> @bodhi, that makes sense. So basically fsck.f2fs
> isn't in initramfs

It is in actually. But the rootfs check was after it was mounted.

FYI, with the new initramfs version, it is somewhat alleviated. The rootfs is now checked before it is mounted (no need for fstab). However, f2fs filesystem is still not up to date with other filesystem as far as feeding information to the system, generally speaking. So currently, the initscripts must be tweaked to run fsck. fsck.f2fs will not work out of the box from mainline installation for this purpose.

-bodhi
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Edited 1 time(s). Last edit at 03/17/2015 06:50PM by bodhi.

F2FS improvement.

The good news: using the latest kernel (linux-4.0.0-kirkwood-tld2), after apt-get upgrade to the latest udev and initramfs-tools in jessie, I was able to boot with f2fs rootfs and checked out the flaws we've discussing here lately. They are working the way we think they should be.

- Using 2 partitions Ext2 /boot and f2fs rootfs on a USB drive.
- Booted with label rootfs in the kernel bootargs.
- Observed initramfs performing fsck on the rootfs during boot. This is possible now because the initramfs does the rootfs fsck during pre-mount.

So, it's ready to be used. But as with any new file system, be careful if you use it to store data.

-bodhi
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@bodhi - sorry for late reply, been a little "busy" ... my experiences with f2fs were that there are still some issues that need ironing out ... I think it's absolutely time for file systems that are aware and built specifically for SDD/Flash, so I hope the issues will be ironed out soon ...

On a more humourous note I managed to "cook" a Sandisk Ultra micro SD card recently on ext4 ... and, doh!, I didn't follow my own advice about overprovisioning ... next time ...

The card I think must have decided that there were too many bad blocks and set itself to read-only ... I think the rationale being, stop the writes in order to not to make things worse by making read only - so that if there's any important data it can be rescued ...

Don Charisma ... because anything is possible with Charisma

My blog - http://DonCharisma.org
Our commercial site - http://DonCharisma.com

Don,

> On a more humourous note I managed to "cook" a
> Sandisk Ultra micro SD card recently on ext4 ...
> and, doh!, I didn't follow my own advice about
> overprovisioning ... next time ...
>

It does happen. Been there done that :))

> The card I think must have decided that there were
> too many bad blocks and set itself to read-only
> ... I think the rationale being, stop the writes
> in order to not to make things worse by making
> read only - so that if there's any important data
> it can be rescued ...

I think the SD cards, does not matter which brand, should be used with as little writes operation as possible.

-bodhi
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@bodhi - couldn't agree more, SD cards seem the most fragile of all, which is OK they are after all designed I think for cameras which shouldn't be write intensive ... for future I'll be doing write intensive stuff on something more robust !

LOL, yup, nothing like destroying a perfectly good piece of hardware through experimenting, it's fun I've realised, eventually !

Cheers

Don Charisma ... because anything is possible with Charisma

My blog - http://DonCharisma.org
Our commercial site - http://DonCharisma.com