Recommended patches for mail server?

Recommended patches for mail server?

[JP Howard]

Hi all,

We've been using Ext3 for a while at FastMail.FM, and have recently
started playing with the htree directory index patch. IO performance
hasn't been as good as we were hoping for, so we've started testing
ReiserFS. Our preliminary results are positive enough that we're going to
try switching some of our servers across to see if Real Life looks as
good as our testing.

We are running kernel 2.4.19, Cyrus 2.4.9, and Postfix 1.1.11, on dual
PIII/Athlon servers with RAID 5 arrays. I'm looking for some advice on
which patches we should be applying to get best performance and
reliability.

There's a bunch of patches in
ftp://ftp.namesys.com/pub/reiserfs-for-2.4/2.4.19.pending/ , but only
01-06 apply cleanly to 2.4.19. Should we be applying all of these
patches? If so, what's the trick to getting 07-13 to apply smoothly?

Then there's Chris Mason's data logging patches. From what I've read, it
sounds like these should improve both speed and reliability. Are they
well tested in production environments? Any reason for us not to use
these? Are many people using data=journal mode? Any benchmarks in mail
server stress tests?

Are there any other patches we should be adding? Our first priority is
ensuring that our servers stay up and that storage is reliable even in
the case of failure; however obviously performance improvements are nice
too!

Finally, has anyone using Cyrus/Postfix made the switch from/to Ext3? Any
comments on the process and results?

Thanks in advance for any info,
  Jeremy Howard
  http://FastMail.FM

Re: Recommended patches for mail server?

[Oleg Drokin]

Hello!

On Tue, Oct 15, 2002 at 09:48:48AM +0000, JP Howard wrote:

> We are running kernel 2.4.19, Cyrus 2.4.9, and Postfix 1.1.11, on dual
> PIII/Athlon servers with RAID 5 arrays. I'm looking for some advice on
> which patches we should be applying to get best performance and
> reliability.

Reiserfs in linux kernel 2.4.19 is pretty reliable already.
Best performance is achieved with data logging patches.

> There's a bunch of patches in
> ftp://ftp.namesys.com/pub/reiserfs-for-2.4/2.4.19.pending/ , but only
> 01-06 apply cleanly to 2.4.19. Should we be applying all of these
> patches? If so, what's the trick to getting 07-13 to apply smoothly?

They should apply cleanly, if you are worried about some offsets, this is
ok and should not concern you. (just use -s switch to patch command
to not see unneeded output ;) )

> Then there's Chris Mason's data logging patches. From what I've read, it
> sounds like these should improve both speed and reliability. Are they
> well tested in production environments? Any reason for us not to use

SuSE is including these into their SuSE 8.1 shipped kernels, so I guess
they are tested. Probably Chris can comment more on this.

> Are there any other patches we should be adding? Our first priority is
> ensuring that our servers stay up and that storage is reliable even in
> the case of failure; however obviously performance improvements are nice
> too!

You may need to apply 05-reiserfs_make_bad_inode.diff from 2.4.19.pending
subdir on our FTP, if you are going to use NFS off reiserfs.

Bye,
    Oleg

Re: Recommended patches for mail server?

[JP Howard]

On Tue, 15 Oct 2002 14:00:54 +0400, "Oleg Drokin" <green@namesys.com>
said:
> Hello!
> 
Hi Oleg! Many thanks for your reply.

> > There's a bunch of patches in
> > ftp://ftp.namesys.com/pub/reiserfs-for-2.4/2.4.19.pending/ , but only
> > 01-06 apply cleanly to 2.4.19. Should we be applying all of these
> > patches? If so, what's the trick to getting 07-13 to apply smoothly?
> 
> They should apply cleanly, if you are worried about some offsets, this is
> ok and should not concern you. (just use -s switch to patch command
> to not see unneeded output ;) )
> 
I got quite a few HUNK FAILED. Also, I found that with the data logging
patches these other patches didn't apply cleanly.

Could you please tell me which, if any, of these patches are important?
Also, I noticed 07-mmaped_data_loss_fix.diff  here:
http://www.uwsg.iu.edu/hypermail/linux/kernel/0201.3/1161.html

Since Cyrus mmap()s files which it also opens directly, is this an
important patch? Any others of these 2.5 patches? Are they backported to
2.4?

> SuSE is including these into their SuSE 8.1 shipped kernels, so I guess
> they are tested. Probably Chris can comment more on this.
> 
That's a pretty good indicator!

> You may need to apply 05-reiserfs_make_bad_inode.diff from 2.4.19.pending
> subdir on our FTP, if you are going to use NFS off reiserfs.
> 
We don't use NFS.

Re: Recommended patches for mail server?

[Oleg Drokin]

Hello!

On Tue, Oct 15, 2002 at 10:55:21AM +0000, JP Howard wrote:

> > They should apply cleanly, if you are worried about some offsets, this is
> > ok and should not concern you. (just use -s switch to patch command
> > to not see unneeded output ;) )
> I got quite a few HUNK FAILED. Also, I found that with the data logging
> patches these other patches didn't apply cleanly.

Hm. You apply the patches in order, is that right?

> Could you please tell me which, if any, of these patches are important?
> Also, I noticed 07-mmaped_data_loss_fix.diff  here:
> http://www.uwsg.iu.edu/hypermail/linux/kernel/0201.3/1161.html

07-mmaped_data_loss_fix.diff is in 2.4.19 already, may be you are just
downloading patches from the wrong dir?

> Since Cyrus mmap()s files which it also opens directly, is this an
> important patch? Any others of these 2.5 patches? Are they backported to

It is importnt, but is included already.

> 2.4?

Other patches are some cosmetic cleanups, also new block allocator,
but this block allocator is uncompatible with Chris' data logging patches yet,
and you need Chris' patches more. There also this NFS fix I recommended and
two not very important fixes that you would probably never ever need.
(fixes are patches 13-remount-rw-fix.diff and 04-item_alignment_fix.diff)

Bye,
    Oleg

Re: Recommended patches for mail server?

[JP Howard]

On Tue, 15 Oct 2002 16:29:23 +0400, "Oleg Drokin"
<green@namesys.com> said:
> On Tue, Oct 15, 2002 at 10:55:21AM +0000, JP Howard wrote:
> > > They should apply cleanly, if you are worried about some offsets,
> > > this is ok and should not concern you. (just use -s switch to patch
> > > command to not see unneeded output ;) )
> > I got quite a few HUNK FAILED. Also, I found that with the data
> > logging patches these other patches didn't apply cleanly.
>
> Hm. You apply the patches in order, is that right?
>
Yes.

> > Could you please tell me which, if any, of these patches are
> > important? Also, I noticed 07-mmaped_data_loss_fix.diff  here:
> > http://www.uwsg.iu.edu/hypermail/linux/kernel/0201.3/1161.html
>
> 07-mmaped_data_loss_fix.diff is in 2.4.19 already, may be you are just
> downloading patches from the wrong dir?
>
I've been searching the archives to see what patches are around. I
noticed this patch and figured it sounded important; it's not related to
my question above about the 2.4.19.pending patches.

> Other patches are some cosmetic cleanups, also new block allocator, but
> this block allocator is uncompatible with Chris' data logging patches
> yet, and you need Chris' patches more. There also this NFS fix I
> recommended and two not very important fixes that you would probably
> never ever need. (fixes are patches 13-remount-rw-fix.diff and
> 04-item_alignment_fix.diff)
>
Well, it sounds like there's nothing for us here to worry about then! If
we ever need NFS, I'll make sure that we apply the patch that you
mentioned.

Thanks again,
  Jeremy