ecryptfs team mailing list archive

[Kai Krakow <kai@xxxxxxxxxxx>]

@Theodore,

> Note that the "fsync causes performance problems meme got" started
> precisely because of ext3's "data=ordered" mode. This is what causes
> all dirty blocks to be pushed out to disks on an fsync(). Using ext4 with
> delayed allocation, or ext3 with data=writeback, fsync() is actually quite fast.

While that may be true (and I suppose it is ;-)) what happens to all
those users sticking to ext3 or similar fs' when "suddenly" all apps to
fsync() on every occassion?

It may not hurt ext4 performance that much but probably other fs'
performance.

I still think the solution lies somewhere between "fix the apps" and
"fix the fs". Correct me if I am wrong but I read, currently Ext4 does
(for yet unknown reasons) out-of-order flushing between data and meta
data which hopefully can be fixed without affecting performance too much
while improving integrity on crashes. Still it is important to fix the
apps which still rely on Ext3s behaviour too much.

/End of @Theodore

Side note:

I'm using XFS so Ext4 isn't my preference but this is still interesting
for me as it looks like XFS and Ext4 share the same oddities that lead
to truncated configs in e.g. KDE4. I lost my kmailrc due to this several
times, including all my filters, account settings, folder settings
etc... (btw: a situation which could be improved if KMail wouldn't work
with a single monolithic config) The situation was already present with
KDE3 and got worse with KDE4 and latest NVIDIA-drivers which is
currently a not-so-stable combination on some hardware (rock-solid on my
Intel-based system at home, pretty unstable on my AMD/Via-based system
at work). And now a clue: Also an open-source driver could have made the
system freeze - that's not a single fault of closed-source drivers. So
some of the arguments here are just irrelevant. That also holds true for
the config database vs. tiny config files arguments.

-- 
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