Re: ubifs mount size

Artem Bityutskiy
2008-08-18T10:46:36Z

Hi,

On Mon, 2008-08-18 at 09:36 +0300, Adrian Hunter wrote:
> dfoley wrote:
> > Does this look right (info below) ?
> > I create a 55MiB volume, but df only shows 33968KiB
> > This is linux-2.6.24.4. I've also used linux-2.6.27-rc3.
> >
> >
> > root@tsi-sa2410:~# ubimkvol /dev/ubi1 -N root -s 55MiB
> > Volume ID 0, size 3755 LEBs (57676800 bytes, 55.0 MiB), LEB size 15360
> > bytes (15.0 KiB), dynamic, name "root", alignment 1
> > root@tsi-sa2410:~# mount -t ubifs ubi1:root /mnt/linux2-root/
> > UBIFS: default file-system created
> > UBIFS: background thread "ubifs_bgt1_0" started, PID 930
> > UBIFS: mounted UBI device 1, volume 0, name "root"
> > UBIFS: file system size: 57292800 bytes (55950 KiB, 54 MiB, 3730 LEBs)
> > UBIFS: journal size: 2872320 bytes (2805 KiB, 2 MiB, 187 LEBs)
> > UBIFS: default compressor: LZO
> > UBIFS: media format 4, latest format 4
> > root@tsi-sa2410:~# df
> > Filesystem 1k-blocks Used Available Use% Mounted on
> > rootfs 8059 5284 2366 69% /
> > /dev/root 8059 5284 2366 69% /
> > /dev/root 8059 5284 2366 69% /dev/.static/dev
> > ubi1:root 33968 0 31204 0% /mnt/linux2-root
>
> Yes this looks right. UBIFS doesn't really know how much data can be fitted
> in the file system, so it makes a worst case estimate.

In practice you will be able to fit more than what df shows. I will
write a corresponding FAQ entry which will explain the issue later.