ecryptfs team mailing list archive

[Theodore Ts'o <tytso@xxxxxxx>]

@Michael,

The trick is being able to determine which applications are being too
aggressive with writing files.  Section 5 in the laptop-mode's FAQ:
http://samwel.tk/laptop_mode/faq has some good tips about how to detect
which applications are writing indiscriminately to the disk.   However,
some amount of work will be necessary to determine how much writing the
applications are doing, and whether it is "justified" or "unjustified".
What we really need is a powertop-like program that tracks write and
inode activity so that application writers can be shamed into fixing
their applications.

"echo 1 > /proc/sys/vm/block_dump" works, but unfortunately you have to
shutdown sysklogd first, and it doesn't summarize information very well.
Ideally we also would also track fsync vs. fdatasync calls.   Creating a
custom ftrace module in the kernel plus a userspace application and then
promulgating it as the next step in trying to reduce battery usage and
promote SSD friendly applications is probably what we need to do.

My concern with encouraging people to file bugs against applications is
whether or not people will accurately file j'accuse! statements against
the correct applications.   If there are too many false positives and/or
false negatives, it might end up being counterproductive.  The advantage
of creating a powertop-like tool is once you have something which can
measured, application authors have something they can optimize against
--- and as they old saying goes, you get what you optimize for.

-- 
Ext4 data loss
https://bugs.launchpad.net/bugs/317781
You received this bug notification because you are a member of eCryptfs,
which is subscribed to ecryptfs-utils in ubuntu.

Status in “ecryptfs-utils” source package in Ubuntu: Invalid
Status in “linux” source package in Ubuntu: Confirmed
Status in ecryptfs-utils in Ubuntu Jaunty: Invalid
Status in linux in Ubuntu Jaunty: Confirmed

Bug description:
I recently installed Kubuntu Jaunty on a new drive, using Ext4 for all my data.

The first time i had this problem was a few days ago when after a power loss ktimetracker's config file was replaced by a 0 byte version . No idea if anything else was affected.. I just noticed ktimetracker right away.

Today, I was experimenting with some BIOS settings that made the system crash right after loading the desktop. After a clean reboot pretty much any file written to by any application (during the previous boot) was 0 bytes.
For example Plasma and some of the KDE core config files were reset. Also some of my MySQL databases were killed...

My EXT4 partitions all use the default settings with no performance tweaks. Barriers on, extents on, ordered data mode..

I used Ext3 for 2 years and I never had any problems after power losses or system crashes.

Jaunty has all the recent updates except for the kernel that i don't upgrade because of bug #315006

ProblemType: Bug
Architecture: amd64
DistroRelease: Ubuntu 9.04
NonfreeKernelModules: nvidia
Package: linux-image-2.6.28-4-generic 2.6.28-4.6
ProcCmdLine: root=UUID=81942248-db70-46ef-97df-836006aad399 ro rootfstype=ext4 vga=791 all_generic_ide elevator=anticipatory
ProcEnviron:
 LANGUAGE=
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.28-4.6-generic
SourcePackage: linux