Nautilus disk cache behaviour

[Tim]

On 15/07/15 19:44, Narcis Garcia wrote:
> Although dilesystem/device write cache is a kernel level feature,
> userspace tools can ask kernel for syncing.
>
> I suppose in UG 32-bit UG variant it's kernel responibility to not apply
> write cache for USB block devices, but in UG 64-bit write cache is
> working for those cases.
>
> When write cache is working, Nautilus calls some sync at end of copying
> files. You can reproduce it with UG 14.04 (64-bits):
> 1. Plug an USB pendrive (4GiB or more)
> 2. Copy there files bigger than 1GiB, from a faster volume (hard disk p.e.)
>
> You will see a reasonable speed from 1% to 99%, but at the end you will
> see Nautilus talking about 0 seconds remaining during large time. When
> Progress dialog closes, pendrive activity finishes inmediately.
> That "large time" lapse only can be the sync task.
Nautilus does not handle such low-level details, it uses the GFile api [1]. If there is a sync call it would be coming from Gio/gvfs

[1] https://developer.gnome.org/gio/stable/GFile.html
>
>
> El 15/07/15 a les 10:57, Tim ha escrit:
>>
>> On 15/07/15 18:51, Narcis Garcia wrote:
>>> Hello,
>>>
>>> I've seen that in Ubuntu-Gnome 14.04 (32-bits), when copying files from
>>> internal device to USB store (such as pendrive), disk write cache is not
>>> working.
>>>
>>> In Ubuntu-Gnome 14.04 (64-bits) disk write cache works (it's better),
>>> but at the end of copy progress bar cache is synced, and I feel is
>>> convenient to wait before doing more write operations.
>>>
>>> My question:
>>> Is there any way to configure Nautilus to not sync write cache at any
>>> time (only when umount, of course)?
>> filesystem write cache is a kernel level feature, I seriously doubt nautilus has any knowledge of that!
>>>
>>