The FC10 ext2 experiment has ended -- don't try this

[Robert Moskowitz]

Bill Davidsen wrote:
> Robert Moskowitz wrote:
>> This is on an ASUS Eee PC netbook with 512Mb memory and a 4Gb SSD and 
>> a 8Gb SD card for more disk capacity (4Gb is simply not enough to 
>> even install FC10).
>>
>> Only /home was on an ext3 partition. /boot, /, and /var were all ext2 
>> partitions.
>>
>> And things had been running well for a month or so. Regularly on cold 
>> boot, it would do an auto check on one of the ext2 partitions and 
>> reboot. Looked good....
>>
>> Last night I suspended the box while plugged into AC; this worked 
>> well and it came right out of suspension this morning (on battery I 
>> use hibernate to save the battery). I then did a yum update.
>>
>> The yum update was taking some time and the screensaver kicked in. 
>> For some reason this triggered the box to go into suspension (it 
>> never went into hibernation when I hibernated then yum update). I 
>> 'knew' bad things were going to happen to suspend right in the middle 
>> of a yum update...
>>
> You might look at your screensaver settings WRT power saving, you may 
> have shot yourself in that foot.

I **thought** I had it set right. I suspect that because my last 
operation was a suspend, when it came out of suspend, something was left 
so when the timer kicked off (I had it set for 20min) for keyb/mouse 
inactivity, it suspended again instead of just going into screensaver.

Of course system the system was hosed, there was no way to find out, and 
I don't think I want to try again!

> Using ext3 is hard on battery life.

I know. Even with noatime, you still have more disk activities. Of 
course, since my 'drives' are SSD and SD, this might not be such a 
difference (ext2 power usage vs ext3).
> Also note there have been recent discussions of ext4 behavior if you 
> shut down hard after writing and before the timer has physically 
> written your data. I don't have details here, so I don't want to 
> spread FUD, but a kernel patch was discussed, and the behavior as 
> described does sound somewhat dangerous for laptop operation.
>
> Okay, the URL was in my history, make you own evaluation:
> http://www.h-online.com/open/Possible-data-loss-in-Ext4--/news/112821
>
> I'm not going to depend on prayer to save my data until 2.6.30 is out 
> and the fix is tested, not do I agree with Ted T'so that the 
> applications should be fixed. 

Is Ted on this list? I did not catch his ID. We worked together in the 
IETF 10 years ago.

> IMHO any sequence of legal system calls should not zero out the files 
> written..., certainly rewriting a block in a file is a pretty normal 
> database operation, and should work at least as well as ext3.
>> Sure enough, inodes broken all over the place. Could NOT recover. 
>> Fortunately, there was nothing lost other than time.
>>
>> I am rebuilding the system right now. I am keeping the partitions as 
>> I had them, but they will all be ext3 and I will change fstab for 
>> noatime...