Re: [gentoo-user] Ext4 status - Alternative to ext2/3 for gentoo portage and more

[Wael Nasreddine]

This One Time, at Band Camp, Florian Philipp <lists@f_philipp.fastmail.net> said, On Fri, Feb 15, 2008 at 10:24:55PM +0100:

> On Fri, 2008-02-15 at 21:05 +0100, Wael Nasreddine wrote:
> > Currently I have 2 partitions, a root and home partition, fortunately
> > on LVM array, I was thinking of splitting them to "/, /usr, /var, /home,
> > /usr/portage, /mnt/storage" the latter is to be used for Mp3z (around
> > 12000) and movies...

> > I was thinking of having the below filesystem schema:
> > /               : ext3 (-j -O dir_index,sparse_super,filetype) (Good mkfs options ??)
> > /usr            : xfs (I never used it so please suggest mkfs.xfs options)
> > /var            : //
> > /home           : ext3 (-m 0 -j -O dir_index,sparse_super,filetype) (Good mkfs options ??)
> > /usr/portage    : ReiserFS (3? 4? options??)
> > /mnt/storage    : ext3 (-m 0 -j -O dir_index,sparse_super,filetype) (Good mkfs options ??)


> > Could you please comment/complete/change the schema above ?? I really
> > would like to speed up my system a little bit, My system is entirely
> > built on LVM array, and LVM is on DM-CRYPT so as you can see it's a
> > quite slow due to the encryption...

> > Oh one last thing, What do you suggest for a server? I have a Gentoo
> > server and uptime can be over 5/6 months, everytime I reboot the
> > server I have to manually scan the filesystem due to errors
> > everywhere, any suggestions??

> > Thanks...

> First of all, if there are filesystem errors, check your cables, your
> controller and your disks. I don't think filesystem errors count as
> normal behavior ...
I should check that out, thanks

> To your filesystem scheme: Why do you use xfs for usr? AFAIK XFS is good
> at write speed but not worth the trouble when reading data and data in
> usr is usually written once, updated every few months and read many
> times a week (on rebooting Desktop PCs maybe once a day). I'd use
> reiserfs3.6, maybe even without notail to make it more space efficient.
I don't use XFS, curently I only have / and /home and I want to split
it to more smaller partitions, I'm on LVM so it's easy, anyway I'm
going with ReiserFS for /usr /var, would you please suggest
mkfs.reiserfs options as I have nerver used ReiserFS-3 before (yep 5
years using linux and I've always used ext3...) also You didn't mention
/var, would you say ReiserFS-3 is a good choice as well?

> I'd also use ext2 on /usr/portage. These data don't need journaling.
> Everything's got an MD5-sum to make sure it's unchanged after a crash
> and you can easily resync. I found ext2 with 2k blocks to be faster than
> reiserfs3.6, even on read-performance.
I've already made the partition as suggested in [1] I used this
command:
$ mke2fs -b 1024 -N 200000 -m 0 -O dir_index

I guess 1K block size would be faster??

> If I were you, I'd also use separate volumes for /tmp and /var/tmp
> (without ccache) with xfs.
What did you mean by 'without ccache'? I have ccache and I use it...

> /home could use data=journal. Those data are precious and if I remember
> correctly, this setting even brings an obscure (i.e. undocumented) speed
> improvement with many parallel disk accesses, for example in a
> multi-user environment.
it's done, thanks, BTW what's your home partition FS? your choice is
ext3 or reiserFS??

One last thing, since I'm on LVM resizing the partition is a must
feature, in ext3 I use resize2fs which works quite nicely, is
resize_reiserfs as reliable as resize2fs is??

[1]: http://gentoo-wiki.com/TIP_Speeding_up_portage#Make_A_Sparse_File_to_create_portage_in

-- 
Wael Nasreddine
http://wael.nasreddine.com
PGP: 1024D/C8DD18A2 06F6 1622 4BC8 4CEB D724  DE12 5565 3945 C8DD 18A2

.: An infinite number of monkeys typing into GNU emacs,
   would never make a good program. (L. Torvalds 1995) :.