Comment 59 for bug 204133

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Colin Ian King (colin-king) wrote :

Hi Ago,

Here is my analysis from several tests on my server box:

1. ntfs-3g mount with syncio is indeed 10-12x slower than the default async ntfs-3g mount.

2. However, if one has a loop-back or dm-loop backed ext3 filesystem inside this then problem is less of an issue due to the buffer-caching at the ext3 layer - essentially the buffer cache at this layer will improve performance significantly.

3. Having ntfs-3g mounted as syncio is only useful with the ext3 filesystem loopbacked inside it to make sure that ext3 writes get written back through the fuse layer. At umount time of the looped back filesystem or calling sync will ensure that the files in the ext3 system are written back correctly to the ntfs-3g fuse layer.

4. Without the syncio mount option, we may see the ext3 filesytem get corrupted if the ntfs3g/ fuse writes are not fully written back to the ntfs filesystem.

I am unsure how Wubi initialises the filesystem during the Wubi install. However, if you are copying an ISO image or large amounts of data over to the ntfs-3g filesystem perhaps mounting it at first without the syncio option is fine. However, once Ubuntu is up and running from a ext3 filesystem which is loopback mounted inside ntfs-3g then a syncio mount option is probably the best way to make sure data is sync'd back correctly to reduce ext3 inconsistency and with enough buffer cache it should perform reasonably well.

Hope this makes sense.

Colin