On Mon 13 Aug 2012 06:46:53 PM IST, Michael Hampicke wrote:

Howdy gentooers,

I am looking for a filesystem that perfomes well for a cache
directory. Here's some data on that dir:
- cache for prescaled images files + metadata files
- nested directory structure ( 20/2022/202231/*files* )
- about 20GB
- 100.000 directories
- about 2 million files

The system has 2x Intel Xon Quad-cores (Nehalem), 16GB of RAM and two
10.000rpm hard drives running a RAID1.

Up until now I was using ext4 with noatime, but I am not happy with
it's performence. Finding and deleting old files with 'find' is
incredible slow, so I am looking for a filesystem that performs
better. First candiate that came to mind was reiserfs, but last time I
tried it, it became slower over time (fragmentation?).
Currently I am running a test with btrfs and so far I am quiet happy
with it as it is much faster in my use case.

Do you guys have any other suggestions? How about JFS? I used that on
my old NAS box because of it's low cpu usage. Should I give reiser4 a
try, or better leave it be given Hans Reiser's current status?

Thx in advance,
Mike


You should have a look at xfs.

I used to use ext4 earlier, traversing through /usr/portage used to be
very slow. When I switched xfs, speed increased drastically.


This might be kind of unrelated, but makes sense.

--
Nilesh Govindrajan
http://nileshgr.com

You should have a look at xfs.


I used to use ext4 earlier, traversing through /usr/portage used to be very slow. When I switched xfs, speed increased drastically.



This might be kind of unrelated, but makes sense.
I guess*traversing*through directories may be faster with XFS, but in my experience ext4 perfoms better than XFS in regard to operations (cp, rm) on small files.
I read that there are some tuning options for XFS and small files, but never tried it.
But if somone seconds XFS I will try it too.

On Aug 13, 2012 9:01 PM, "Michael Hampicke" <mgehampicke@gmail.com> wrote:

>>

>> You should have a look at xfs.

>>

>> I used to use ext4 earlier, traversing through /usr/portage used to be very slow. When I switched xfs, speed increased drastically.

>>

>> This might be kind of unrelated, but makes sense.

>

>

> I guess*traversing*through directories may be faster with XFS, but in my experience ext4 perfoms better than XFS in regard to operations (cp, rm) on small files.

> I read that there are some tuning options for XFS and small files, but never tried it.

>

> But if somone seconds XFS I will try it too.


Have you indexed your ext4 partition?


# tune2fs -O dir_index /dev/your_partition

# e2fsck -D /dev/your_partition


Rgds,

On 13.08.2012 15:16, Michael Hampicke wrote:
> - about 20GB
> - 100.000 directories
> - about 2 million files
>
> The system has 2x Intel Xon Quad-cores (Nehalem), 16GB of RAM and two
> 10.000rpm hard drives running a RAID1.
1st thought: switch to SSDs
2nd thought: maybe lots of writes? -> get a SSD for the fs metadata
3rd thought: purging old files with "find"? your cache system should
have some kind of DB that holds that information.

Michael Hampicke wrote:






You should have a look at xfs.



I used to use ext4 earlier, traversing through /usr/portage
used to be very slow. When I switched xfs, speed increased
drastically.



This might be kind of unrelated, but makes sense.



I guess*traversing*through directories may be faster with
XFS, but in my experience ext4 perfoms better than XFS in
regard to operations (cp, rm) on small files.
I read that there are some tuning options for XFS and small
files, but never tried it.



But if somone seconds XFS I will try it too.




It's been a while since I messed with this but isn't XFS the one
that hates power failures and such?*



Dale



:-) :-)*

--
I am only responsible for what I said ... Not for what you understood or how you interpreted my words!

Have you indexed your ext4 partition?


# tune2fs -O dir_index /dev/your_partition

# e2fsck -D /dev/your_partition
Hi, the dir_index is active. I guess that's why delete operations take as long as they take (index has to be updated every time)*

On Mon, Aug 13, 2012 at 10:42 AM, Michael Hampicke <mgehampicke@gmail.com> wrote:


Have you indexed your ext4 partition?


# tune2fs -O dir_index /dev/your_partition

# e2fsck -D /dev/your_partition
Hi, the dir_index is active. I guess that's why delete operations take as long as they take (index has to be updated every time)*

1) Scan for files to remove2) disable index3) Remove files4) enable index

?
--
:wq

2012/8/13 Daniel Troeder <daniel@admin-box.com>

On 13.08.2012 15:16, Michael Hampicke wrote:

> - about 20GB

> - 100.000 directories

> - about 2 million files

>

> The system has 2x Intel Xon Quad-cores (Nehalem), 16GB of RAM and two

> 10.000rpm hard drives running a RAID1.

1st thought: switch to SSDs

2nd thought: maybe lots of writes? -> get a SSD for the fs metadata

3rd thought: purging old files with "find"? your cache system should

have some kind of DB that holds that information.




1: SSDs are not possible atm. The machine is in a data center abroad.2: Writes are not that much of a problem at this time.3: Well, it's a 3rd party application that - in theory - should take care of removing old files. Sadly, it does not work as it's supposed to be, While time passes the number of orphans grow

I guess*traversing*through directories may be faster with
XFS, but in my experience ext4 perfoms better than XFS in
regard to operations (cp, rm) on small files.
I read that there are some tuning options for XFS and small
files, but never tried it.



But if somone seconds XFS I will try it too.




It's been a while since I messed with this but isn't XFS the one
that hates power failures and such?*



Dale



:-) :-)*

--
I am only responsible for what I said ... Not for what you understood or how you interpreted my words!



Well, it's the delayed allocation of XFS (which prevents fragmentation) that does not like sudden power losses But ext4 has that too, you can disable it though - that should be true for XFS too.
But the power situation in the datacenter has never been a problem so far, and even if the cache partition get's screwed, we can always rebuild it. Takes a few hours, but it would not be the end of the world

On Mon 13 Aug 2012 08:28:15 PM IST, Michael Hampicke wrote:

I guess traversing through directories may be faster with XFS,
but in my experience ext4 perfoms better than XFS in regard to
operations (cp, rm) on small files.
I read that there are some tuning options for XFS and small
files, but never tried it.

But if somone seconds XFS I will try it too.


It's been a while since I messed with this but isn't XFS the one
that hates power failures and such?

Dale

:-) :-)

--
I am only responsible for what I said ... Not for what you understood or how you interpreted my words!

Well, it's the delayed allocation of XFS (which prevents
fragmentation) that does not like sudden power losses But ext4 has
that too, you can disable it though - that should be true for XFS too.
But the power situation in the datacenter has never been a problem so
far, and even if the cache partition get's screwed, we can always
rebuild it. Takes a few hours, but it would not be the end of the world


Yes, XFS hates power failures. I got a giant UPS for my home desktop to
use XFS because of it's excellent performance ;-)


--
Nilesh Govindrajan
http://nileshgr.com