slow mount

slow mount

[Herbie Hopkins]

It seems to take a very long time to mount a large reiserfs filesystem:

  $ time mount /home
 
  real    0m17.259s
  user    0m0.000s
  sys     0m0.000s

  $ df -h

  Filesystem            Size  Used Avail Use% Mounted on
  [snip]
  /dev/hda7              44G   12G   33G  26% /home

is this normal behaviour? as this drastically increases my system statup
time. The same partition formatted to ext3 mounts in less than a second
and this also seems to have no reflection on the amount of data on the
partition as it still takes this long when the filesystem in empty.

Any help would be appretiated, thanks.
Herbie

Re: slow mount

[Yury Umanets]

Herbie Hopkins wrote:

>It seems to take a very long time to mount a large reiserfs filesystem:
>
>  $ time mount /home
> 
>  real    0m17.259s
>  user    0m0.000s
>  sys     0m0.000s
>
>  $ df -h
>
>  Filesystem            Size  Used Avail Use% Mounted on
>  [snip]
>  /dev/hda7              44G   12G   33G  26% /home
>
>is this normal behaviour? as this drastically increases my system statup
>time. The same partition formatted to ext3 mounts in less than a second
>and this also seems to have no reflection on the amount of data on the
>partition as it still takes this long when the filesystem in empty.
>
>Any help would be appretiated, thanks.
>Herbie
>
>
>
>  
>
Bitmaps are read in mount time. And this realy does not depend on data 
amount, only on filesystem size.

-- 
Yury Umanets
"We're flying high, we're watching the world passes by..."

Re: slow mount

[Alex Zarochentsev]

On Thu, Jun 12, 2003 at 03:20:29PM +0100, Herbie Hopkins wrote:
> It seems to take a very long time to mount a large reiserfs filesystem:
> 
>   $ time mount /home
>  
>   real    0m17.259s
>   user    0m0.000s
>   sys     0m0.000s
> 
>   $ df -h
> 
>   Filesystem            Size  Used Avail Use% Mounted on
>   [snip]
>   /dev/hda7              44G   12G   33G  26% /home
> 
> is this normal behaviour? as this drastically increases my system statup

Yes. It is normal.

There are  44G / 128M ~= 350 bitmap blocks which are read by reiserfs 
at mount time.

> time. The same partition formatted to ext3 mounts in less than a second
> and this also seems to have no reflection on the amount of data on the
> partition as it still takes this long when the filesystem in empty.
> 
> Any help would be appretiated, thanks.
> Herbie
> 

-- 
Alex.

Re: slow mount

[Chris Mason]

On Thu, 2003-06-12 at 10:20, Herbie Hopkins wrote:
> It seems to take a very long time to mount a large reiserfs filesystem:
> 
>   $ time mount /home
>  
>   real    0m17.259s
>   user    0m0.000s
>   sys     0m0.000s

Which kernel?  2.4.20 or so had improvements in this area

-chris

Re: slow mount

[Herbie Hopkins]

I'm using 2.4.20.

On Thu, 2003-06-12 at 15:39, Chris Mason wrote:
> On Thu, 2003-06-12 at 10:20, Herbie Hopkins wrote:
> > It seems to take a very long time to mount a large reiserfs filesystem:
> > 
> >   $ time mount /home
> >  
> >   real    0m17.259s
> >   user    0m0.000s
> >   sys     0m0.000s
> 
> Which kernel?  2.4.20 or so had improvements in this area
> 
> -chris
> 

Re: slow mount

[Oleg Drokin]

Hello!

On Thu, Jun 12, 2003 at 03:20:29PM +0100, Herbie Hopkins wrote:
> It seems to take a very long time to mount a large reiserfs filesystem:
>   $ time mount /home
>   real    0m17.259s
>   /dev/hda7              44G   12G   33G  26% /home
> is this normal behaviour? as this drastically increases my system statup

Well. Some kind of a delay is certainly expected, as reiserfs is reading
all the bitmaps at mount time.

> time. The same partition formatted to ext3 mounts in less than a second
> and this also seems to have no reflection on the amount of data on the
> partition as it still takes this long when the filesystem in empty.

The bitmaps are there no matter if filesystem is empty or not.

Only my 20G fs can be mounted in 1.4s, so may be you have some kind of very slow
drive, or no DMA or something like that?

Bye,
    Oleg

Re: slow mount

[Herbie Hopkins]

slow drive? Not really:

$cat /proc/ide/via
Transfer Mode:       UDMA      
Address Setup:       30ns      
Cmd Active:          90ns      
Cmd Recovery:        30ns      
Data Active:         90ns      
Data Recovery:       30ns      
Cycle Time:          15ns      
Transfer Rate:     133.3MB/s

$hdparm -Tt /dev/hda
/dev/hda:
 Timing buffer-cache reads:   128 MB in  0.42 seconds =304.76 MB/sec
 Timing buffered disk reads:  64 MB in  1.26 seconds = 50.79 MB/sec


On Thu, 2003-06-12 at 15:46, Oleg Drokin wrote:
> Hello!
> 
> On Thu, Jun 12, 2003 at 03:20:29PM +0100, Herbie Hopkins wrote:
> > It seems to take a very long time to mount a large reiserfs filesystem:
> >   $ time mount /home
> >   real    0m17.259s
> >   /dev/hda7              44G   12G   33G  26% /home
> > is this normal behaviour? as this drastically increases my system statup
> 
> Well. Some kind of a delay is certainly expected, as reiserfs is reading
> all the bitmaps at mount time.
> 
> > time. The same partition formatted to ext3 mounts in less than a second
> > and this also seems to have no reflection on the amount of data on the
> > partition as it still takes this long when the filesystem in empty.
> 
> The bitmaps are there no matter if filesystem is empty or not.
> 
> Only my 20G fs can be mounted in 1.4s, so may be you have some kind of very slow
> drive, or no DMA or something like that?
> 
> Bye,
>     Oleg

Re: slow mount

[Herbie Hopkins]

Interestingly enough a 20G fs on the same drive takes 0.9s to mount.
Should a 40G partition not take roughly twice as long as a 20G partition
to mount? 

On Thu, 2003-06-12 at 15:46, Oleg Drokin wrote:
> Hello!
> 
> On Thu, Jun 12, 2003 at 03:20:29PM +0100, Herbie Hopkins wrote:
> > It seems to take a very long time to mount a large reiserfs filesystem:
> >   $ time mount /home
> >   real    0m17.259s
> >   /dev/hda7              44G   12G   33G  26% /home
> > is this normal behaviour? as this drastically increases my system statup
> 
> Well. Some kind of a delay is certainly expected, as reiserfs is reading
> all the bitmaps at mount time.
> 
> > time. The same partition formatted to ext3 mounts in less than a second
> > and this also seems to have no reflection on the amount of data on the
> > partition as it still takes this long when the filesystem in empty.
> 
> The bitmaps are there no matter if filesystem is empty or not.
> 
> Only my 20G fs can be mounted in 1.4s, so may be you have some kind of very slow
> drive, or no DMA or something like that?
> 
> Bye,
>     Oleg

Re: slow mount

[Hans Reiser]

Herbie Hopkins wrote:

>Interestingly enough a 20G fs on the same drive takes 0.9s to mount.
>Should a 40G partition not take roughly twice as long as a 20G partition
>to mount? 
>
Yes.

>
>On Thu, 2003-06-12 at 15:46, Oleg Drokin wrote:
>  
>
>>Hello!
>>
>>On Thu, Jun 12, 2003 at 03:20:29PM +0100, Herbie Hopkins wrote:
>>    
>>
>>>It seems to take a very long time to mount a large reiserfs filesystem:
>>>  $ time mount /home
>>>  real    0m17.259s
>>>  /dev/hda7              44G   12G   33G  26% /home
>>>is this normal behaviour? as this drastically increases my system statup
>>>      
>>>
>>Well. Some kind of a delay is certainly expected, as reiserfs is reading
>>all the bitmaps at mount time.
>>
>>    
>>
>>>time. The same partition formatted to ext3 mounts in less than a second
>>>and this also seems to have no reflection on the amount of data on the
>>>partition as it still takes this long when the filesystem in empty.
>>>      
>>>
>>The bitmaps are there no matter if filesystem is empty or not.
>>
>>Only my 20G fs can be mounted in 1.4s, so may be you have some kind of very slow
>>drive, or no DMA or something like that?
>>
>>Bye,
>>    Oleg
>>    
>>
>
>
>
>  
>
Is the hardware starting to fail and doing lots of retries maybe?

-- 
Hans

Re: slow mount

[Herbie Hopkins]

On Thu, 2003-06-12 at 16:56, Hans Reiser wrote:
> Is the hardware starting to fail and doing lots of retries maybe?

I sure hope not as the drive is only a couple of months old. Booting a
kernel with CONFIG_REISERFS_CHECK=y dmesg gives me:

reiserfs:warning: CONFIG_REISERFS_CHECK is set ON
reiserfs:warning: - it is slow mode for debugging.
reiserfs: checking transaction log (device 03:07) ...
journal-1153: found in header: first_unflushed_offset 465,
last_flushed_trans_id 84176
journal-1206: Starting replay from offset 465, trans_id 84177
journal-1299: Setting newest_mount_id to 95
Using r5 hash to sort names
ReiserFS version 3.6.25

which looks normal to me.

Re: slow mount

[Oleg Drokin]

Hello!

On Thu, Jun 12, 2003 at 05:24:50PM +0100, Herbie Hopkins wrote:
> > Is the hardware starting to fail and doing lots of retries maybe?
> I sure hope not as the drive is only a couple of months old. Booting a
> kernel with CONFIG_REISERFS_CHECK=y dmesg gives me:
> reiserfs:warning: CONFIG_REISERFS_CHECK is set ON
> reiserfs:warning: - it is slow mode for debugging.
> reiserfs: checking transaction log (device 03:07) ...
> journal-1153: found in header: first_unflushed_offset 465,
> last_flushed_trans_id 84176
> journal-1206: Starting replay from offset 465, trans_id 84177
> journal-1299: Setting newest_mount_id to 95
> Using r5 hash to sort names
> ReiserFS version 3.6.25
> which looks normal to me.

What if you turn off this debugging stuff that is certainly slows down all the operations by a lot?
Corresponding kernel option (compile-time) is CONFIG_REISERFS_CHECK

Bye,
    Oleg

Re: slow mount

[Herbie Hopkins]

I don't have the dubuging stuff on at the moment, I just compiled
another kernel with it enabled to see what extra info it gave me.

On Thu, 2003-06-12 at 18:26, Oleg Drokin wrote:
> Hello!
> 
> On Thu, Jun 12, 2003 at 05:24:50PM +0100, Herbie Hopkins wrote:
> > > Is the hardware starting to fail and doing lots of retries maybe?
> > I sure hope not as the drive is only a couple of months old. Booting a
> > kernel with CONFIG_REISERFS_CHECK=y dmesg gives me:
> > reiserfs:warning: CONFIG_REISERFS_CHECK is set ON
> > reiserfs:warning: - it is slow mode for debugging.
> > reiserfs: checking transaction log (device 03:07) ...
> > journal-1153: found in header: first_unflushed_offset 465,
> > last_flushed_trans_id 84176
> > journal-1206: Starting replay from offset 465, trans_id 84177
> > journal-1299: Setting newest_mount_id to 95
> > Using r5 hash to sort names
> > ReiserFS version 3.6.25
> > which looks normal to me.
> 
> What if you turn off this debugging stuff that is certainly slows down all the operations by a lot?
> Corresponding kernel option (compile-time) is CONFIG_REISERFS_CHECK
> 
> Bye,
>     Oleg

Re: slow mount

[Oleg Drokin]

Hello!

On Thu, Jun 12, 2003 at 06:33:37PM +0100, Herbie Hopkins wrote:

> I don't have the dubuging stuff on at the moment, I just compiled
> another kernel with it enabled to see what extra info it gave me.

Ah, I see.
Well, if the drive itself is inducing those delays, you cannot tell that from
fs driver, but you probably can look around with smartctl and see how many
relocated bad sectors it have and this kind of stuff.

Bye,
    Oleg