[LAD] [OT] bash vs disk activity

[Rui Nuno Capela]

On Tue, October 9, 2007 12:11, Lars Luthman wrote:
> On Tue, 2007-10-09 at 14:02 +0300, Sampo Savolainen wrote:
>
>> Quoting Patrick Shirkey <pshirkey at boosthardware.com>:
>>
>>
>>> For example if I transfer 200mb to a usb disk the copy command takes
>>> about 30 seconds before it returns and the data takes about 5 minutes
>>> before it is actually finished being transferred and the device is
>>> unmountable.
>>
>> quick-hack(tm)
>>
>> (cp -a /xxx /usb_device && sync) &
>>
>>
>> But remember sync flushes _everything_.
>>
>
> Slightly-slower-hack: add the 'sync' option to whatever script or config
> file is used to mount the device (/etc/fstab, udev rules, KDE service menu
> etc). That way all writes will be synchronised automatically.
>

just a little note of warning on this last one, specially if the usb drive
is of the solid-state/flash type: the mount sync option used to force
every block write and, besides it used to take much longer to complete the
transfer, that used to shorten the media life, it wears out you know?

that was specially true when copying large files or batches of too many,
too many times. I've been bitten by this one and already trashed too many
sd cards when I was ripping complete movies (200MB+) for my son's gp2x :)

i don't know whether this still applies to latest kernels, or to any
particular filesystem, as I'm avoiding the sync mount option on removable
media (usually vfat formatted) for about a year now, but I would like to
be wrong ;)

cheers
-- 
rncbc aka Rui Nuno Capela
rncbc at rncbc.org