Messages in this thread | | | Date | Mon, 26 May 2008 19:38:48 +0200 | From | Jan Kara <> | Subject | Re: Top 10 bugs/warnings for the week of March 23rd, 2008 |
| |
On Mon 26-05-08 19:28:23, Bart Van Assche wrote: > On Mon, May 26, 2008 at 7:09 PM, Oliver Neukum <oliver@neukum.org> wrote: > > Am Montag 26 Mai 2008 19:01:48 schrieb Theodore Tso: > >> If the USB stack folks would like to work on how to recognize that > >> it's the same USB stick that had been previously pulled, so that it > >> gets the same block device, and we can decide for how long we should > >> keep dirty buffers around associated with a pulled USB stick, we can > >> certainly have that conversation. :-) > > > > Even if we could tell whether the device has remained the same, how > > would we know the medium wasn't exchanged? > > Looking at the filesystem UUID could help -- this is an ID that is > present as data on the disk, and that is even independent of the bus > type. See also /dev/disk/by-uuid. Yes, but as Oliver wrote if someone modified the filesystem in the mean time, you won't notice it - UUID doesn't help here.
> For the journaling filesystems I am familiar with the default value > for the commit parameter is 5 seconds. Would it be a good idea to > leave the default to 5s for non-removable devices, and to change this > default to 1s for removable devices ? I don't think it's a good idea: 1) You'd even more stress wear-leveling of USB flash drives - btw, given their sizes it does not make much sence to use ext3 on your USB stick. I still use VFAT/ext2 there.
2) You'd probably notice performance decrease because of more journaling overhead.
Honza -- Jan Kara <jack@suse.cz> SUSE Labs, CR
| |