reiserfs mount time

reiserfs mount time

[Jan Engelhardt]

Hi,


brought to attentino on an irc channel, reiser seems to have the largest 
mount times for big partitions. I see this behavior on at least two 
machines (160G, 250G) and one specially-crafted virtual machine
(a 1.9TB disk / 1.9TB partition - took somewhere over 120 seconds).
Here's a dig http://linuxgazette.net/122/misc/piszcz/group001/image002.png 
from http://linuxgazette.net/122/TWDT.html#piszcz
So, any hint from the reiserfs developers how come reiserfs takes so long?
Standard mkreiserfs options (none extra passed).


Jan Engelhardt
-- 

Re: reiserfs mount time

[Tomasz Torcz]

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On Sun, Jan 08, 2006 at 11:24:02PM +0100, Jan Engelhardt wrote:
> Hi,
> 
> 
> brought to attentino on an irc channel, reiser seems to have the largest 
> mount times for big partitions. I see this behavior on at least two 
> machines (160G, 250G) and one specially-crafted virtual machine
> (a 1.9TB disk / 1.9TB partition - took somewhere over 120 seconds).

  My 177 GiB partition on SATA disc takes about 10 seconds to mount. It
is 1/3 of Linux boot time :(

-- 
Tomasz Torcz                                                       72->|   80->|
zdzichu@irc.-nie.spam-.pl                                          72->|   80->|


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Re: reiserfs mount time

[Lee Revell]

On Sun, 2006-01-08 at 23:24 +0100, Jan Engelhardt wrote:
> Hi,
> 
> 
> brought to attentino on an irc channel, reiser seems to have the largest 
> mount times for big partitions. I see this behavior on at least two 
> machines (160G, 250G) and one specially-crafted virtual machine
> (a 1.9TB disk / 1.9TB partition - took somewhere over 120 seconds).
> Here's a dig http://linuxgazette.net/122/misc/piszcz/group001/image002.png 
> from http://linuxgazette.net/122/TWDT.html#piszcz
> So, any hint from the reiserfs developers how come reiserfs takes so long?
> Standard mkreiserfs options (none extra passed).
> 

reiser3 or reiser4?

Lee

Re: reiserfs mount time

[Jan Engelhardt]

>> 
>> brought to attentino on an irc channel, reiser seems to have the largest 
>> mount times for big partitions. I see this behavior on at least two 
>> machines (160G, 250G) and one specially-crafted virtual machine
>> (a 1.9TB disk / 1.9TB partition - took somewhere over 120 seconds).
>> Here's a dig http://linuxgazette.net/122/misc/piszcz/group001/image002.png 
>> from http://linuxgazette.net/122/TWDT.html#piszcz
>> So, any hint from the reiserfs developers how come reiserfs takes so long?
>> Standard mkreiserfs options (none extra passed).
>
>reiser3 or reiser4?

For my case, reiser3.

(According to that pic link (from irc) also reiser4, but I'm inclined not 
to believe that one.)


Jan Engelhardt
-- 
| Alphagate Systems, http://alphagate.hopto.org/
| jengelh's site, http://jengelh.hopto.org/

Re: reiserfs mount time

[Lee Revell]

On Mon, 2006-01-09 at 17:18 +0100, Jan Engelhardt wrote:
> >> 
> >> brought to attentino on an irc channel, reiser seems to have the largest 
> >> mount times for big partitions. I see this behavior on at least two 
> >> machines (160G, 250G) and one specially-crafted virtual machine
> >> (a 1.9TB disk / 1.9TB partition - took somewhere over 120 seconds).
> >> Here's a dig http://linuxgazette.net/122/misc/piszcz/group001/image002.png 
> >> from http://linuxgazette.net/122/TWDT.html#piszcz
> >> So, any hint from the reiserfs developers how come reiserfs takes so long?
> >> Standard mkreiserfs options (none extra passed).
> >
> >reiser3 or reiser4?
> 
> For my case, reiser3.
> 
> (According to that pic link (from irc) also reiser4, but I'm inclined not 
> to believe that one.)

reiser3 is in maintenance mode so is unlikely to be fixed.  If you still
have the problem with reiser4 then they would probably like to hear
about it.

Lee

Re: reiserfs mount time

[Jan Kara]

  Hello,

> brought to attentino on an irc channel, reiser seems to have the largest 
> mount times for big partitions. I see this behavior on at least two 
> machines (160G, 250G) and one specially-crafted virtual machine
> (a 1.9TB disk / 1.9TB partition - took somewhere over 120 seconds).
> Here's a dig http://linuxgazette.net/122/misc/piszcz/group001/image002.png 
> from http://linuxgazette.net/122/TWDT.html#piszcz
> So, any hint from the reiserfs developers how come reiserfs takes so long?
> Standard mkreiserfs options (none extra passed).
  If I remember correctly, the problem is reiserfs loads bitmaps on mount
and that takes most of the time. Jeff Mahoney <jeffm@suse.com> has
patches fixing this but I think Hans rejected them because he wants only
bugfixes in reiser3...

								Honza

-- 
Jan Kara <jack@suse.cz>
SuSE CR Labs

Re: reiserfs mount time

[Jeffrey Mahoney]

Jan Kara wrote:
>   Hello,
> 
> 
>>brought to attentino on an irc channel, reiser seems to have the largest 
>>mount times for big partitions. I see this behavior on at least two 
>>machines (160G, 250G) and one specially-crafted virtual machine
>>(a 1.9TB disk / 1.9TB partition - took somewhere over 120 seconds).
>>Here's a dig http://linuxgazette.net/122/misc/piszcz/group001/image002.png 
>>from http://linuxgazette.net/122/TWDT.html#piszcz
>>So, any hint from the reiserfs developers how come reiserfs takes so long?
>>Standard mkreiserfs options (none extra passed).
> 
>   If I remember correctly, the problem is reiserfs loads bitmaps on mount
> and that takes most of the time. Jeff Mahoney <jeffm@suse.com> has
> patches fixing this but I think Hans rejected them because he wants only
> bugfixes in reiser3...

Yeah, that's the right analysis. ReiserFS caches bitmaps on mount and
for large file systems it can take a quite a long time. I've heard
reports of up to 15 minutes on multi-TB file systems.

As far as these patches getting accepted, Hans was opposed to them
initially, but emailed in September saying he decided that they should
be accepted after all.

These were against 2.6.12.1, and I remerged and split the patches out
yesterday evening. I'm going to do a bit of testing and send them out on
Monday for inclusion in -mm.

-Jeff

--
Jeff Mahoney
SUSE Labs

Re: reiserfs mount time

[Jan Engelhardt]

>>>brought to attentino on an irc channel, reiser seems to have the largest 
>>>mount times for big partitions. I see this behavior on at least two 
>>>machines (160G, 250G) and one specially-crafted virtual machine
>>>(a 1.9TB disk / 1.9TB partition - took somewhere over 120 seconds).
>>>Here's a dig http://linuxgazette.net/122/misc/piszcz/group001/image002.png 
>>>from http://linuxgazette.net/122/TWDT.html#piszcz
>>>So, any hint from the reiserfs developers how come reiserfs takes so long?
>>>Standard mkreiserfs options (none extra passed).
>> 
>>   If I remember correctly, the problem is reiserfs loads bitmaps on mount
>> and that takes most of the time. Jeff Mahoney <jeffm@suse.com> has
>> patches fixing this but I think Hans rejected them because he wants only
>> bugfixes in reiser3...
>
>Yeah, that's the right analysis. ReiserFS caches bitmaps on mount and
>for large file systems it can take a quite a long time.

And quite some memory. But never mind, I already migrated by now.
(Not because of mount time, but other factors.)



Jan Engelhardt
--