Configurations for performance

Hi,

Sorry if this has been answered before, but I'm looking
moving our 
mailboxes across to dbmail (about 10,000 users) and I'd like
to know if 
there are any tips for configuring the MySQL server / dbmail
to be able 
to handle this load? I am using MySQL version 5.0.32 on
linux 2.6.18. Am 
I better to use innodb with a raw partition for its data or
is there a 
preferred filesystem to put this on (ext3 / xfs /
reiserfs?).

To get high availability I want to use drbd over a gigabit
network link. 
>From my experience this shouldn't affect performance too
much. On each 
server I have a pair of SATA hard disks in a software
RAID1.

If anyone can give me a few pointers or send me some urls of
info I'd 
really appreciate it.

Thanks,
Josh.
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Hi Josh,

To be honest, I don't think 1) SATA 2) Software RAID1 is
going to cut  
it. I think you'll bottleneck on the drives. If you want
good  
performance and redundancy look at spending a few extra
bucks on SAS  
drives and either RAID 01 or RAID 10.

Stephen

Quoting Josh Marshall <joshtestmail.worldhosting.org>:

> Hi,
>
> Sorry if this has been answered before, but I'm looking
moving our
> mailboxes across to dbmail (about 10,000 users) and I'd
like to know if
> there are any tips for configuring the MySQL server /
dbmail to be able
> to handle this load? I am using MySQL version 5.0.32 on
linux 2.6.18.
> Am I better to use innodb with a raw partition for its
data or is there
> a preferred filesystem to put this on (ext3 / xfs /
reiserfs?).
>
> To get high availability I want to use drbd over a
gigabit network link.
>> From my experience this shouldn't affect
performance too much. On each
> server I have a pair of SATA hard disks in a software
RAID1.
>
> If anyone can give me a few pointers or send me some
urls of info I'd
> really appreciate it.
>
> Thanks,
> Josh.
> _______________________________________________
> DBmail mailing list
> DBmaildbmail.org
> htt
ps://mailman.fastxs.nl/mailman/listinfo/dbmail


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Stephen Loeckle wrote:

> To be honest, I don't think 1) SATA 2) Software RAID1
is going to cut 
> it. I think you'll bottleneck on the drives. If you
want good 
> performance and redundancy look at spending a few extra
bucks on SAS 
> drives and either RAID 01 or RAID 10.

I agree with Stephen. How many servers are there? Maybe a
SAN with SCSI 
or SAS drives would make even more sense in that case.
They'll be 
sitting in the same rack anyway. Correct?

> Quoting Josh Marshall <joshtestmail.worldhosting.org>:

>> Sorry if this has been answered before, but I'm
looking moving our
>> mailboxes across to dbmail (about 10,000 users) and
I'd like to know if
>> there are any tips for configuring the MySQL server
/ dbmail to be able
>> to handle this load? I am using MySQL version
5.0.32 on linux 2.6.18.
>> Am I better to use innodb with a raw partition for
its data or is there
>> a preferred filesystem to put this on (ext3 / xfs /
reiserfs?).

IIRC it was possible to give InnoDB a raw partition and it
would live on 
it happily by itself, so you would loose the operating
system's 
filesystem overhead. Alas I have never done that with
mysql/InnoDB, only 
Informix. So I don't know how much if at all it helps.

Also, 10k users would be POP3 only or do they have IMAP too?
How many 
servers and with what configuration have you planned? I'm
just curious 
here, as my biggest dbmail install is only ~600 IMAP users.

HTH,
	Alex
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Actually we use SATA, in RAID5 with XFS. With just not 10K
users.  
Works like a charm.
However we're on Postgres, not mysql.


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>
> Either way it's probably a good idea for me to
investigate using  
> database replication rather than drbd.


We actually don't do any replication, or similar.
For recovery if filesystem fails we use postgres with PITR.

/Marc
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> Is a PITR with postgres relatively fast? I have to
consider the  
> downtime. I realise that filesystem / server failures
are fairly  
> rare but I just want to cover myself in case of
emergency.
>

That depends on
1) How often you take a complete snapshot (this is done
live!)
2) the amount of data transfered in and out of the database
between  
snapshots.

But you have to keep in mind, there is no automatic
fall-over here,  
and such. So you have to get off bed at 06.00 :P





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At least go with hardware raid and stay away from software
raid. Get a  
couple $400 LSI SATA RAID cards and add them to your
existing boxes.  
It's pretty darn fast and the recovery after drive failure
is much  
easier and cleaner.

Stephen

Quoting Josh <joshtestmail.worldhosting.org>:

> Hi everyone, thankyou for your responses. I'll try to
address
> everyone's comments in the one email.
>> I agree with Stephen. How many servers are there?
Maybe a SAN with   
>> SCSI or SAS drives would make even more sense in
that case. They'll  
>>  be sitting in the same rack anyway. Correct?

> Unfortunately we already have the machines, they are 1U
with two 160Gb
> SATA disks, 2.5Gb RAM with 3GHz CPU. We have three
identical machines
> with 2xGb ethernet, we'll be using one for crossover to
keep the data
> in sync between two of them and the other to connect to
the network.
> I've got dbmail running on all three, and MySQL data is
shared via a
> drbd and managed with heartbeat between two of them.
>

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