FAQ Search Today's Posts Mark Forums Read
» Video Reviews

» Linux Archive

Linux-archive is a website aiming to archive linux email lists and to make them easily accessible for linux users/developers.


» Sponsor

» Partners

» Sponsor

Go Back   Linux Archive > Gentoo > Gentoo User

 
 
LinkBack Thread Tools
 
Old 09-05-2012, 09:26 AM
Neil Bothwick
 
Default aligning SSD partitions

On Wed, 5 Sep 2012 05:02:49 -0400, Philip Webb wrote:

> > 'man mount' explains it all ...
>
> Well, it outlines it (smile).

:-)

I'll rephrase that:

'man mount' explains it all, for small values of all.

> > ... but the option you want is size, which defaults to 50 % .
>
> That looks ok : I assume that's the maximum,
> ie it doesn't take up that much memory unless it's needed.

Exactly, it uses what it needs, size sets the upper limit.


--
Neil Bothwick

With 7 billion people on earth chances are slim it will ever be *your*
day.
 
Old 09-05-2012, 11:07 AM
Dale
 
Default aligning SSD partitions

Peter Humphrey wrote:
> On Wednesday 05 September 2012 10:02:49 Philip Webb wrote:
>> 120905 Neil Bothwick wrote:
>>> On Tue, 4 Sep 2012 20:42:56 -0400, Philip Webb wrote:
>>>> What is the best line for /etc/fstab ? The only example I have is
> :
>>>> 'tmpfs /tmp tmpfs defaults,noatime,mode=1777 0 0'
>>>>
>>>> This doesn't seem to limit the size in any way.
>>> 'man mount' explains it all ...
>> Well, it outlines it (smile).
>>
>>> ... but the option you want is size, which defaults to 50 % .
>> That looks ok : I assume that's the maximum,
>> ie it doesn't take up that much memory unless it's needed.
> The kernel only uses as much tmpfs as it needs at any given time. If it
> needs more than has been specified, it starts rolling less active parts
> out to swap. So if you don't have a lot of memory, you can still specify
> more tmpfs than you have RAM and everything will just work.
>
> The only reason I specify a large tmpfs is to be able to compile Libre
> Office. At other times it just isn't used.
>


I let mine default to half of ram but when I need to compile LOo, then I
have to manually increase it. I guess 8Gbs isn't enough. Come to think
of it, I updated LOo the other day and it didn't complain about it being
less than 8Gbs. I guess it doesn't need as much as it used to. Code
clean up??

I might also add, I see no speed improvements in putting portages work
directory on tmpfs. I have tested this a few times and the difference
in compile times is just not there.

Dale

:-) :-)

--
I am only responsible for what I said ... Not for what you understood or how you interpreted my words!
 
Old 09-05-2012, 11:25 AM
Peter Humphrey
 
Default aligning SSD partitions

On Wednesday 05 September 2012 12:07:13 Dale wrote:

> I might also add, I see no speed improvements in putting portages
> work directory on tmpfs. I have tested this a few times and the
> difference in compile times is just not there.

Yes, I'd forgotten that. I just haven't got round to changing it. It
works, so I haven't fixed it. :-)

--
Rgds
Peter
 
Old 09-05-2012, 12:02 PM
Dale
 
Default aligning SSD partitions

Peter Humphrey wrote:
> On Wednesday 05 September 2012 12:07:13 Dale wrote:
>
>> I might also add, I see no speed improvements in putting portages
>> work directory on tmpfs. I have tested this a few times and the
>> difference in compile times is just not there.
> Yes, I'd forgotten that. I just haven't got round to changing it. It
> works, so I haven't fixed it. :-)
>

I leave mine on too. I figure the ram will not suffer wear and tear
like a hard drive will. Compiling is a good bit of writing, deleting
and such and I just think doing that in ram, since it is temporary
anyway, is a better deal in the long run. I would think that would be a
good idea when using a SSD.

Off topic a bit. I been using ext4 for my file system since I moved
drives around. It has a defrag tool that is just plain wonderful. For
anyone that uses ext4, try the command e4defrag. It's simple to use.
To check it, e4defrag -c <device, mount point or even a specific file or
directory>. If you want it to actually defrag it, just remove the -c
option. I find that after a big update, like KDE, it helps to defrag
/usr. I defrag my /home on occasion too. I'm still downloading a LOT
of TV shows and movies. That goodness for LVM.

LOL

Dale

:-) :-)

--
I am only responsible for what I said ... Not for what you understood or how you interpreted my words!
 
Old 09-05-2012, 12:31 PM
Neil Bothwick
 
Default aligning SSD partitions

On Wed, 05 Sep 2012 06:07:13 -0500, Dale wrote:

> I might also add, I see no speed improvements in putting portages work
> directory on tmpfs. I have tested this a few times and the difference
> in compile times is just not there.

Probably because with 16GB everything stays cached anyway.


--
Neil Bothwick

If the cops arrest a mime, do they tell her she has the right to remain
silent?
 
Old 09-05-2012, 12:52 PM
Dale
 
Default aligning SSD partitions

Neil Bothwick wrote:
> On Wed, 05 Sep 2012 06:07:13 -0500, Dale wrote:
>
>> I might also add, I see no speed improvements in putting portages work
>> directory on tmpfs. I have tested this a few times and the difference
>> in compile times is just not there.
> Probably because with 16GB everything stays cached anyway.
>
>


I cleared the cache between the compiles. This is the command I use:

echo 3 > /proc/sys/vm/drop_caches

That clears all cache from what I read and it also shows up as cleared
in top too. It's amazing how much cache can build up over time. Right
now, just about all my ram, 16Gbs worth, is used. I check it with
gkrellm. It seems no matter how much ram you have, it will use it for
something.

Still, no difference. There is also a thread on the forums on this
too. I think I posted my results on there but it was a while back. I
think I ran that while in single user mode too.

Dale

:-) :-)

--
I am only responsible for what I said ... Not for what you understood or how you interpreted my words!
 
Old 09-05-2012, 12:55 PM
Adam Carter
 
Default aligning SSD partitions

>> I might also add, I see no speed improvements in putting portages work
>> directory on tmpfs. I have tested this a few times and the difference
>> in compile times is just not there.
>
> Probably because with 16GB everything stays cached anyway.

Would it still be useful to use tmpfs if you wanted to keep drive
writes down on an SSD? I imagine even tho its cached it would get
written to disk after a timer expires, so while it doesn't affect
performance it does reduce the drive life.
 
Old 09-05-2012, 12:58 PM
Peter Humphrey
 
Default aligning SSD partitions

On Wednesday 05 September 2012 13:02:01 Dale wrote:

> I find that after a big update, like KDE, it helps to defrag /usr.

Interesting. I've just run sudo e4defrag -c /usr and got a fragmentation
of zero. That's after upgrading KDE last week.

Then I ran it on all the nine ext4 partitions here and only two had
nonzero fragmentations; one was 1 and the other 2.

Looks like I can forget about it on this box.

--
Rgds
Peter
 
Old 09-05-2012, 03:17 PM
Neil Bothwick
 
Default aligning SSD partitions

On Wed, 05 Sep 2012 07:52:45 -0500, Dale wrote:

> >> I might also add, I see no speed improvements in putting portages
> >> work directory on tmpfs. I have tested this a few times and the
> >> difference in compile times is just not there.
> > Probably because with 16GB everything stays cached anyway.

> I cleared the cache between the compiles. This is the command I use:
>
> echo 3 > /proc/sys/vm/drop_caches

But you are still using the RAM as disk cache during the emerge, the data
doesn't stay around long enough to need to get written to disk with so
much RAM for cache.


--
Neil Bothwick

"There are no stupid questions, just too many inquisitive idiots."
 
Old 09-05-2012, 03:23 PM
Michael Mol
 
Default aligning SSD partitions

On Wed, Sep 5, 2012 at 11:17 AM, Neil Bothwick <neil@digimed.co.uk> wrote:
> On Wed, 05 Sep 2012 07:52:45 -0500, Dale wrote:
>
>> >> I might also add, I see no speed improvements in putting portages
>> >> work directory on tmpfs. I have tested this a few times and the
>> >> difference in compile times is just not there.
>> > Probably because with 16GB everything stays cached anyway.
>
>> I cleared the cache between the compiles. This is the command I use:
>>
>> echo 3 > /proc/sys/vm/drop_caches
>
> But you are still using the RAM as disk cache during the emerge, the data
> doesn't stay around long enough to need to get written to disk with so
> much RAM for cache.

Indeed. Try setting the mount to write-through to see the difference.


--
:wq
 

Thread Tools




All times are GMT. The time now is 09:23 PM.

VBulletin, Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO ©2007, Crawlability, Inc.
Copyright 2007 - 2008, www.linux-archive.org