F15 ext4 discard option - why not default?

[Ville Skyttä]

On 03/16/2011 08:40 PM, Michael Cronenworth wrote:
> Thorsten Leemhuis wrote:
>> Just curious. I have a Intel SSDSA2M080G2GC for a while now but was not
>> bold enough yet to give discard on Ext4 a try.
> 
> I use discard with my Intel G2 SSDs on Btrfs in a RAID0 configuration 
> (2.6.37 kernel). I have not had issues with missing data, corrupt data, 
> or slow performance with copying, moving, creating, or deleting files 
> and folders. I've been running this configuration for about 3 months now.

I had a 40GB Intel G2 X25-V since last May until February, ran ext4 with
discard on it for several months without problems.  But in February it
started to generate SMART errors and the reallocated sector count
increased to about 10 in a day or two (according to smartctl), got
"media error" related messages in syslog and and eventually it became
unbootable and I was not able to rescue all data off it.  No idea if it
was due to discard or something else (I also updated the disk firmware
in February before the problems started to appear), and I no longer have
the disk.