truncated files

truncated files

[Martin Steigerwald]

Hi!

Today on one try to hibernate via tuxonice it machine appeared dead. I am 
not completely sure if it was. But I was in a hurry and had no time to 
try to ping or SSH it from a different machine and thus I just switched 
it off hard.

After booting again which worked fine, parts of my KDE configuration 
appeared broken. Color scheme and window position was lost. And KMail did 
not know how to sent out a mail anymore, all transports were missing.

Thus I checked my /home filesystem on /dev/sda5 this evening. It appeared 
absolutely fine with xfs_check and xfs_repair -n from xfsprogs 2.9.8 
(grml 2008.11rc).

But comparing some of the config files of KDE with the versions in my 
backup showed truncated files:

martin@shambhala:~> ls -l .kde-backup-2008-11-22/share/config/kmailrc
-rw------- 1 martin martin 247680 22. Nov 
18:29 .kde-backup-2008-11-22/share/config/kmailrc

martin@shambhala:~> ls -l .kde-broken-2008-11-25/share/config/kmailrc
-rw------- 1 martin martin 116902 25. Nov 
21:16 .kde-broken-2008-11-25/share/config/kmailrc

But no hole in it:

martin@shambhala:~> 
su -c "xfs_bmap -v .kde-broken-2008-11-25/share/config/kmailrc"
Passwort:
.kde-broken-2008-11-25/share/config/kmailrc:
 EXT: FILE-OFFSET      BLOCK-RANGE        AG AG-OFFSET            TOTAL
   0: [0..231]:        22444768..22444999  0 (22444768..22444999)   232


Similar stuff happened on the encfs encrypted KDE user that I use for 
professional stuff - encfs is layered on top of XFS via FUSE:

shambhala:~ms> ls -l .kde-broken-2008-11-25/share/config/kdeglobals
-rw------- 1 ms teamix 4772 25. Nov 
20:35 .kde-broken-2008-11-25/share/config/kdeglobals
shambhala:~ms> ls -l .kde-backup-2008-11-22/share/config/kdeglobals
-rw------- 1 ms teamix 6621 18. Nov 
16:13 .kde-backup-2008-11-22/share/config/kdeglobals

Unfortunately I cannot check this one for holes directly as its on encfs:

shambhala:~ms> xfs_bmap -v .kde-broken-2008-11-25/share/config/kdeglobals
xfs_bmap: specified file 
[".kde-broken-2008-11-25/share/config/kdeglobals"] is not on an XFS 
filesystem

(Since encfs encrypted pathes as well and the file length may differ a 
bit, the encrypted file could be difficult to find... well maybe by 
date.)

And well my basket index was lost (http://basket.kde.org is a note taking 
application):

shambhala:~ms> 
ls -l .kde-backup-2008-11-22/share/apps/basket/baskets/baskets.xml
-rw-r--r-- 1 ms teamix 10271 18. Nov 
15:03 .kde-backup-2008-11-22/share/apps/basket/baskets/baskets.xml
shambhala:~ms> 
ls -l .kde-broken-2008-11-25/share/apps/basket/baskets/baskets.xml
-rw-r--r-- 1 ms teamix 1905 25. Nov 
13:24 .kde-broken-2008-11-25/share/apps/basket/baskets/baskets.xml



But since I found no holes in the other file and AFAIK the truncated file 
problem has long been solved - anyone has a idea, how this could have 
happened?

I fixed it by copying ~/.kde/share/config for my private user, and 
complete ~/.kde for my company user from the backup last weekend. In 
~/.kde/share/apps for the private too much has changed since the backup, 
thus for the moment I left it. I do not miss anything in there right now, 
but feel a tad bit uncomfortable that files might be truncated in there 
also and I might only find out later when I already worked with them for 
some time.

I thought that KDE maybe was writing those files at the moment. But its a 
bit wide-spread for that. And it must have happened that it wrote to 
config / app files on two user accounts. Might be the explaination, but I 
am not completely convinced.

I did not have seen a thing like this since at least a year I think.


This is with:

martin@shambhala:~> cat /proc/version
Linux version 2.6.27.7-tp42-toi-3.0-rc7a (martin@shambhala) (gcc version 
4.3.2 (Debian 4.3.2-1) ) #1 PREEMPT Mon Nov 24 11:30:39 CET 2008

I did not find anything cumbersone in /var/log/syslog... no XFS crash or 
something like this.


If no one has any idea I take this as really bad luck. Might really be 
that I turned off the machine while quite some KDE files were being 
written out. I know that some KDE applications make backups prior to 
overwriting. Maybe something could be improved in KDE applications. If 
so, I would be interested to hear and I would file bug reports with KDE.

Well actually thats my bet already. XFS appears to be fine.

Ciao,
-- 
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA  B82F 991B EAAC A599 84C7

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truncated files

[Martin Steigerwald]

Hi!

Today on one try to hibernate via tuxonice it machine appeared dead. I am 
not completely sure if it was. But I was in a hurry and had no time to 
try to ping or SSH it from a different machine and thus I just switched 
it off hard.

After booting again which worked fine, parts of my KDE configuration 
appeared broken. Color scheme and window position was lost. And KMail did 
not know how to sent out a mail anymore, all transports were missing.

Thus I checked my /home filesystem on /dev/sda5 this evening. It appeared 
absolutely fine with xfs_check and xfs_repair -n from xfsprogs 2.9.8 
(grml 2008.11rc).

But comparing some of the config files of KDE with the versions in my 
backup showed truncated files:

martin@shambhala:~> ls -l .kde-backup-2008-11-22/share/config/kmailrc
-rw------- 1 martin martin 247680 22. Nov 
18:29 .kde-backup-2008-11-22/share/config/kmailrc

martin@shambhala:~> ls -l .kde-broken-2008-11-25/share/config/kmailrc
-rw------- 1 martin martin 116902 25. Nov 
21:16 .kde-broken-2008-11-25/share/config/kmailrc

But no hole in it:

martin@shambhala:~> 
su -c "xfs_bmap -v .kde-broken-2008-11-25/share/config/kmailrc"
Passwort:
.kde-broken-2008-11-25/share/config/kmailrc:
 EXT: FILE-OFFSET      BLOCK-RANGE        AG AG-OFFSET            TOTAL
   0: [0..231]:        22444768..22444999  0 (22444768..22444999)   232


Similar stuff happened on the encfs encrypted KDE user that I use for 
professional stuff - encfs is layered on top of XFS via FUSE:

shambhala:~ms> ls -l .kde-broken-2008-11-25/share/config/kdeglobals
-rw------- 1 ms teamix 4772 25. Nov 
20:35 .kde-broken-2008-11-25/share/config/kdeglobals
shambhala:~ms> ls -l .kde-backup-2008-11-22/share/config/kdeglobals
-rw------- 1 ms teamix 6621 18. Nov 
16:13 .kde-backup-2008-11-22/share/config/kdeglobals

Unfortunately I cannot check this one for holes directly as its on encfs:

shambhala:~ms> xfs_bmap -v .kde-broken-2008-11-25/share/config/kdeglobals
xfs_bmap: specified file 
[".kde-broken-2008-11-25/share/config/kdeglobals"] is not on an XFS 
filesystem

(Since encfs encrypted pathes as well and the file length may differ a 
bit, the encrypted file could be difficult to find... well maybe by 
date.)

And well my basket index was lost (http://basket.kde.org is a note taking 
application):

shambhala:~ms> 
ls -l .kde-backup-2008-11-22/share/apps/basket/baskets/baskets.xml
-rw-r--r-- 1 ms teamix 10271 18. Nov 
15:03 .kde-backup-2008-11-22/share/apps/basket/baskets/baskets.xml
shambhala:~ms> 
ls -l .kde-broken-2008-11-25/share/apps/basket/baskets/baskets.xml
-rw-r--r-- 1 ms teamix 1905 25. Nov 
13:24 .kde-broken-2008-11-25/share/apps/basket/baskets/baskets.xml



But since I found no holes in the other file and AFAIK the truncated file 
problem has long been solved - anyone has a idea, how this could have 
happened?

I fixed it by copying ~/.kde/share/config for my private user, and 
complete ~/.kde for my company user from the backup last weekend. In 
~/.kde/share/apps for the private too much has changed since the backup, 
thus for the moment I left it. I do not miss anything in there right now, 
but feel a tad bit uncomfortable that files might be truncated in there 
also and I might only find out later when I already worked with them for 
some time.

I thought that KDE maybe was writing those files at the moment. But its a 
bit wide-spread for that. And it must have happened that it wrote to 
config / app files on two user accounts. Might be the explaination, but I 
am not completely convinced.

I did not have seen a thing like this since at least a year I think.


This is with:

martin@shambhala:~> cat /proc/version
Linux version 2.6.27.7-tp42-toi-3.0-rc7a (martin@shambhala) (gcc version 
4.3.2 (Debian 4.3.2-1) ) #1 PREEMPT Mon Nov 24 11:30:39 CET 2008

I did not find anything cumbersone in /var/log/syslog... no XFS crash or 
something like this.


If no one has any idea I take this as really bad luck. Might really be 
that I turned off the machine while quite some KDE files were being 
written out. I know that some KDE applications make backups prior to 
overwriting. Maybe something could be improved in KDE applications. If 
so, I would be interested to hear and I would file bug reports with KDE.

Well actually thats my bet already. XFS appears to be fine.

Ciao,
-- 
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA  B82F 991B EAAC A599 84C7

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Re: truncated files

[Dave Chinner]

On Tue, Nov 25, 2008 at 10:44:14PM +0100, Martin Steigerwald wrote:
> 
> Hi!
> 
> Today on one try to hibernate via tuxonice it machine appeared dead. I am 
                      ^^^^^^^^^
When (not if) suspend to disk/resume fails, you get to keep all the broken
pieces of your filesystem. It works most of the time, but it has
some fundamentally broken corner cases that you probably just
hit....

> Similar stuff happened on the encfs encrypted KDE user that I use for 
> professional stuff - encfs is layered on top of XFS via FUSE:

IIRC, FUSE cannot be suspended safely at all, so expect corruption
of FUSE filesystems on a failed suspend.

I've never had a system that suspends reliably (let alone resumes
from the suspend) so it's no real surprise that I don't trust
suspend to disk....

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

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Re: truncated files

[Martin Steigerwald]

Am Dienstag 25 November 2008 schrieb Dave Chinner:
> On Tue, Nov 25, 2008 at 10:44:14PM +0100, Martin Steigerwald wrote:
> > Hi!
> >
> > Today on one try to hibernate via tuxonice it machine appeared dead.
> > I am
>
>                       ^^^^^^^^^
> When (not if) suspend to disk/resume fails, you get to keep all the
> broken pieces of your filesystem. It works most of the time, but it has
> some fundamentally broken corner cases that you probably just
> hit....

Well I use TuxOnIce for a reason! I had uptimes of up to 70 days with it 
already. And they are usually only interrupted by kernel updates or 
manual shutdowns. I was never convinced by in-kernel solutions for 
hibernate.

> > Similar stuff happened on the encfs encrypted KDE user that I use for
> > professional stuff - encfs is layered on top of XFS via FUSE:
>
> IIRC, FUSE cannot be suspended safely at all, so expect corruption
> of FUSE filesystems on a failed suspend.

Ok, fair enough. My private data isn't on encfs tough.

> I've never had a system that suspends reliably (let alone resumes
> from the suspend) so it's no real surprise that I don't trust
> suspend to disk....

Well I take it as bad luck then, especially since there are no hints that 
XFS had a problem. I am not sure whether the machine really was dead, but 
I can't reproduce what exactly happened. So thats it.

Ciao,
-- 
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA  B82F 991B EAAC A599 84C7

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Re: truncated files

[Dave Chinner]

On Wed, Nov 26, 2008 at 09:49:18AM +0100, Martin Steigerwald wrote:
> Am Dienstag 25 November 2008 schrieb Dave Chinner:
> > On Tue, Nov 25, 2008 at 10:44:14PM +0100, Martin Steigerwald wrote:
> > > Hi!
> > >
> > > Today on one try to hibernate via tuxonice it machine appeared dead.
> > > I am
> >
> >                       ^^^^^^^^^
> > When (not if) suspend to disk/resume fails, you get to keep all the
> > broken pieces of your filesystem. It works most of the time, but it has
> > some fundamentally broken corner cases that you probably just
> > hit....
> 
> Well I use TuxOnIce for a reason! I had uptimes of up to 70 days with it 
> already. And they are usually only interrupted by kernel updates or 
> manual shutdowns. I was never convinced by in-kernel solutions for 
> hibernate.

Sure, though I'm not convinced that TuxOnIce is any better because
it still uses the same fundamental design as the in-kernel ones.

> > I've never had a system that suspends reliably (let alone resumes
> > from the suspend) so it's no real surprise that I don't trust
> > suspend to disk....
> 
> Well I take it as bad luck then, especially since there are no hints that 
> XFS had a problem. I am not sure whether the machine really was dead, but 
> I can't reproduce what exactly happened. So thats it.

And therein lies the problem. I can't get suspend/resume to work
reliably on anything I own, so I can't do anything about problems
reported as a result of suspend/resume. Hell, I even considered
running linux on my new laptop inside a virtual machine on windows
just so I could have functioning suspend/resume....

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

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Re: truncated files

[Martin Steigerwald]

Am Mittwoch 26 November 2008 schrieb Dave Chinner:
> On Wed, Nov 26, 2008 at 09:49:18AM +0100, Martin Steigerwald wrote:
> > Am Dienstag 25 November 2008 schrieb Dave Chinner:
> > > On Tue, Nov 25, 2008 at 10:44:14PM +0100, Martin Steigerwald wrote:
> > > > Hi!
> > > >
> > > > Today on one try to hibernate via tuxonice it machine appeared
> > > > dead. I am
> > >
> > >                       ^^^^^^^^^
> > > When (not if) suspend to disk/resume fails, you get to keep all the
> > > broken pieces of your filesystem. It works most of the time, but it
> > > has some fundamentally broken corner cases that you probably just
> > > hit....
> >
> > Well I use TuxOnIce for a reason! I had uptimes of up to 70 days with
> > it already. And they are usually only interrupted by kernel updates
> > or manual shutdowns. I was never convinced by in-kernel solutions for
> > hibernate.
>
> Sure, though I'm not convinced that TuxOnIce is any better because
> it still uses the same fundamental design as the in-kernel ones.

Might be.

But something is fishy here. I had it a second time today. This time I 
know for sure that the machine freezed hard. Mouse pointer froze and the 
machine didn't even respond to a ping anymore. Nothing in logs - doesn't 
surprise me.

I didn't have this issue with 2.6.26, and I also don't think I had it with 
2.6.27.5. I will downgrade to 2.6.27.5 now.

> > > I've never had a system that suspends reliably (let alone resumes
> > > from the suspend) so it's no real surprise that I don't trust
> > > suspend to disk....
> >
> > Well I take it as bad luck then, especially since there are no hints
> > that XFS had a problem. I am not sure whether the machine really was
> > dead, but I can't reproduce what exactly happened. So thats it.
>
> And therein lies the problem. I can't get suspend/resume to work
> reliably on anything I own, so I can't do anything about problems
> reported as a result of suspend/resume. Hell, I even considered
> running linux on my new laptop inside a virtual machine on windows
> just so I could have functioning suspend/resume....

Then you really had back luck. TuxOnIce works stable for me - at least it 
did so for a long long while, until my recent kernel.

Ciao,
-- 
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA  B82F 991B EAAC A599 84C7

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Re: truncated files

[Martin Steigerwald]

Am Freitag 28 November 2008 schrieb Martin Steigerwald:
> Am Mittwoch 26 November 2008 schrieb Dave Chinner:
> > On Wed, Nov 26, 2008 at 09:49:18AM +0100, Martin Steigerwald wrote:
> > > Am Dienstag 25 November 2008 schrieb Dave Chinner:
> > > > On Tue, Nov 25, 2008 at 10:44:14PM +0100, Martin Steigerwald 
wrote:
> > > > > Hi!
> > > > >
> > > > > Today on one try to hibernate via tuxonice it machine appeared
> > > > > dead. I am
> > > >
> > > >                       ^^^^^^^^^
> > > > When (not if) suspend to disk/resume fails, you get to keep all
> > > > the broken pieces of your filesystem. It works most of the time,
> > > > but it has some fundamentally broken corner cases that you
> > > > probably just hit....
> > >
> > > Well I use TuxOnIce for a reason! I had uptimes of up to 70 days
> > > with it already. And they are usually only interrupted by kernel
> > > updates or manual shutdowns. I was never convinced by in-kernel
> > > solutions for hibernate.
> >
> > Sure, though I'm not convinced that TuxOnIce is any better because
> > it still uses the same fundamental design as the in-kernel ones.
>
> Might be.
>
> But something is fishy here. I had it a second time today. This time I
> know for sure that the machine freezed hard. Mouse pointer froze and
> the machine didn't even respond to a ping anymore. Nothing in logs -
> doesn't surprise me.
>
> I didn't have this issue with 2.6.26, and I also don't think I had it
> with 2.6.27.5. I will downgrade to 2.6.27.5 now.

I wonder about those truncated files nonetheless. As I don't think that 
KDE is writing config files all the time. Well I might be wrong, but I 
didn't even change KDE configuration during time of the crash... OTOH XFS 
uses a in memory inode size and should be safe with the point in time 
when it writes the size to disk as far as I read here. Well this time at 
least again the file "kdeglobals" was affected and this file might be 
written rather often.

Anyway, since I am not even using an official TuxOnIce patch... lets see 
what the downgrade to 2.6.27.5 brings - no time to really dig deeper into 
that right now.

Maybe I should update notebook kernels a little less. 2.6.25.3,6,8,10 
worked nicer than 2.6.26.5 which has had hangs on USB sound on my T23 
Amarok machine, especially after several hibernate cycles.

Or use the Debian distro kernel, but I never had much luck with hibernate 
with that. Might be worth trying again.

-- 
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA  B82F 991B EAAC A599 84C7

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