[arch-general] Hacking into HAL's mount process

[Mauro Santos]

On 03/14/2010 02:21 PM, Nilesh Govindarajan wrote:
> On 03/14/2010 07:41 PM, Robert Howard wrote:
>> Yes, it's all placebo effect. What seems like faster transfers is
>> really the
>> use of write caching and not a good idea for removable media. Could leave
>> the data and filesystem in inconsistent states if the device were
>> accidentally removed or if power failed.
>>
>> On Mar 14, 2010 4:33 AM, "Ray Rashif"<schivmeister at gmail.com>  wrote:
>>
>> On 13/03/2010, Nilesh Govindarajan<lists at itech7.com>  wrote:
>>> By default HAL adds the flush flag wh...
>> Funny..I remember the very reason for making "flush" a default mount
>> option was because users were frantically trying to convince everyone
>> around that it would allow for optimal performance of flash-based
>> storage, aside from running the risk of losing data without it.
>>
>>
>> -- 
>> GPG/PGP ID: B42DDCAD
> 
> @Ray,
> If the device has small buffer size, then it takes lot of time. Who
> want's to shell out more bucks for this simple flush thing to get a
> device with bigger buffer size.
> 
> @Robert,
> Power would fail if there was no UPS. But I have one.
> 
> Also, my transfers are super slow. It takes more than 15 minutes to
> transfer 500 megs !!
> 
> Previously I used to boast among my friends for Linux being fast with
> USB transfers.
> 

I have to agree with the use of an UPS, it helps not only to avoid data
loss but also hardware damage, and these days you can get a cheap UPS
that can supply power for a reasonable amount of time.

On the device being accidentally removed, either way you can have data
loss, also people should really unmount and check the device is idle
before removing it, otherwise bad things can happen.

Most devices have an activity indicator and users should have the good
sense to look at that indicator (when it exists) to check for activity
before removing the device, even when properly unmounting a device ...
although I guess some users will never learn and will complain when bad
thing happen because of a problem that is between the keyboard and the
chair.

Caching may also help if you perform several changes (writes and reads)
in the device before committing all changes, as in deleting many files
or writing many files.