F15 ext4 discard option - why not default?

[Dariusz J. Garbowski]

On 16/03/11 01:03 PM, Michał Piotrowski wrote:
> 2011/3/16 Jeff Moyer<jmoyer at redhat.com>:
>> Michał Piotrowski<mkkp4x4 at gmail.com>  writes:
>>
>>> 2011/3/16 Jeff Moyer<jmoyer at redhat.com>:
>>>> Out of curiosity, what SSD do you have?
>>>
>>> ocz vertex 2
>>
>> OK, haven't tested those.
>
> So far, I can not say anything about it. I just installed system.

I've been using OCZ Vertex 2 with ext4 and discard for about a month now.
No issues.

# mount |sort |grep /dev/sda
/dev/sda1 on /boot type ext2 (rw,noatime)
/dev/sda2 on / type ext4 (rw,noatime,discard)

# smartctl -i /dev/sda
smartctl 5.40 2010-10-16 r3189 [x86_64-redhat-linux-gnu] (local build)
Copyright (C) 2002-10 by Bruce Allen, http://smartmontools.sourceforge.net

=== START OF INFORMATION SECTION ===
Model Family:     SandForce Driven SSDs
Device Model:     OCZ-VERTEX2
Serial Number:    OCZ-MPQS5B86KYJ9HBMI
Firmware Version: 1.29
User Capacity:    115,033,153,536 bytes
Device is:        In smartctl database [for details use: -P show]
ATA Version is:   8
ATA Standard is:  ATA-8-ACS revision 6
Local Time is:    Wed Mar 16 19:11:48 2011 MDT
SMART support is: Available - device has SMART capability.
SMART support is: Enabled