mysql & RAID

Hi,

I am working on configuring a new hardware database server. I'm a little
confused as to what to do about disk. We have several mysql databases but by
far the 2 most active are spamassassin bayesian rules and horde3/imp web
mail. Both do a lot of updates. The bayesian rules are added to each time a
spam message comes in for any of our 200 users. And the horde3/imp writes
address book updates and preferences quite often.

I have read (and have been told) to stay away from RAID-5 for
update-intensive systems. Are there performance concerns with RAID-10 as
well? We will be buying from Dell (done deal for reasons too complicated to
go into) and the disks they're selling are 146 Gb. I can get up to 8 of them
in the server we're buying. I asked them about just getting 2 big disks and
going with RAID-1.

My understanding is that with RAID-10, the system can do multiple reads and
writes simultaneously so throughput is improved oversystems w/o RAID or with
RAID-1. But the same logic would apply to RAID-5 only it doesn't work out
that way.

I just want to make sure I'm configuring this system correctly before I
order it.


--
MySQL General Mailing List
For list archives: http://lists.mysql.com/mysql
To unsubscribe: http://lists.mysql.com/mysql?unsub=gcdmg-mysql-2@m.gmane.org

Re: mysql & RAID

In the last episode (Mar 10), John G. Heim said:
> I have read (and have been told) to stay away from RAID-5 for
> update-intensive systems. Are there performance concerns with RAID-10 as
> well? We will be buying from Dell (done deal for reasons too complicated
> to go into) and the disks they're selling are 146 Gb. I can get up to 8
> of them in the server we're buying. I asked them about just getting 2 big
> disks and going with RAID-1.
>
> My understanding is that with RAID-10, the system can do multiple reads and
> writes simultaneously so throughput is improved oversystems w/o RAID or with
> RAID-1. But the same logic would apply to RAID-5 only it doesn't work out
> that way.

RAID-5 has an extra penalty on small random writes due to the I/O required
to maintain the parity blocks (it does 2 reads and 2 writes for every write
your app does). RAID-10 is just a mirror so it doesn't have to worry about
that.

--
Dan Nelson
dnelson@allantgroup.com

--
MySQL General Mailing List
For list archives: http://lists.mysql.com/mysql
To unsubscribe: http://lists.mysql.com/mysql?unsub=gcdmg-mysql-2@m.gmane.org

Re: mysql & RAID

On Wed, March 10, 2010 09:04, Dan Nelson wrote:
> In the last episode (Mar 10), John G. Heim said:
>> I have read (and have been told) to stay away from RAID-5 for
>> update-intensive systems. Are there performance concerns with RAID-10
>> as
>> well? We will be buying from Dell (done deal for reasons too
>> complicated
>> to go into) and the disks they're selling are 146 Gb. I can get up to 8
>> of them in the server we're buying. I asked them about just getting 2
>> big
>> disks and going with RAID-1.
>>
>> My understanding is that with RAID-10, the system can do multiple reads
>> and
>> writes simultaneously so throughput is improved oversystems w/o RAID or
>> with
>> RAID-1. But the same logic would apply to RAID-5 only it doesn't work
>> out
>> that way.
>
> RAID-5 has an extra penalty on small random writes due to the I/O required
> to maintain the parity blocks (it does 2 reads and 2 writes for every
> write
> your app does). RAID-10 is just a mirror so it doesn't have to worry
> about
> that.
>
> --
> Dan Nelson
> dnelson@allantgroup.com
>
If you can get the disk cheap you might want to get one or two extras and
keep them as spares.

------
William R. Mussatto
Systems Engineer
http://www.csz.com
909-920-9154


--
MySQL General Mailing List
For list archives: http://lists.mysql.com/mysql
To unsubscribe: http://lists.mysql.com/mysql?unsub=gcdmg-mysql-2@m.gmane.org

Re: mysql & RAID

--- On Wed, 10/3/10, John G. Heim wrote: > Hi,=
=0A> =0A> I am working on configuring a new hardware database server.=0A> I=
'm a little confused as to what to do about disk. We have=0A> several mysql=
databases but by far the 2 most active are=0A> spamassassin bayesian rules=
and horde3/imp web mail. Both do=0A> a lot of updates. The bayesian rules =
are added to each time=0A> a spam message comes in for any of our 200 users=
.. And the=0A> horde3/imp writes address book updates and preferences quite=
=0A> often.=0A> =0A> I have read (and have been told) to stay away from RAI=
D-5=0A> for update-intensive systems. Are there performance concerns=0A> wi=
th RAID-10 as well? We will be buying from Dell (done deal=0A> for reasons =
too complicated to go into) and the disks=0A> they're selling are 146 Gb. I=
can get up to 8 of them in the=0A> server we're buying. I asked them about=
just getting 2 big=0A> disks and going with RAID-1.=0A> =0A> My understand=
ing is that with RAID-10, the system can do=0A> multiple reads and writes s=
imultaneously so throughput is=0A> improved oversystems w/o RAID or with RA=
ID-1. But the same=0A> logic would apply to RAID-5 only it doesn't work out=
that=0A> way.=0A> =0A> I just want to make sure I'm configuring this syste=
m=0A> correctly before I order it.=0A> As dan already stated, the wri=
te penalty of raid 5 doesn't really make it a good fit for databases, go wi=
th raid 10. Like you for reasons beyond my control I've been stuck wit=
h dell hardware, just beware of dell raid controllers. The perc6 isn't too =
bad, however I still swap them out for more capable controllers. Pretty muc=
h everything before the perc6 is complete junk. =0A

--
MySQL General Mailing List
For list archives: http://lists.mysql.com/mysql
To unsubscribe: http://lists.mysql.com/mysql?unsub=3Dgcdmg-mysql-2@m.gmane.o rg

Re: mysql & RAID

--0016e6d7eefa2ef02e0481ec8fc9
Content-Type: text/plain; charset=ISO-8859-1

http://assets.en.oreilly.com/1/event/27/Linux%20Filesystem%2 0Performance%20for%20Databases%20Presentation.pdf

2010/3/10 John G. Heim

> Hi,
>
> I am working on configuring a new hardware database server. I'm a little
> confused as to what to do about disk. We have several mysql databases but by
> far the 2 most active are spamassassin bayesian rules and horde3/imp web
> mail. Both do a lot of updates. The bayesian rules are added to each time a
> spam message comes in for any of our 200 users. And the horde3/imp writes
> address book updates and preferences quite often.
>
> I have read (and have been told) to stay away from RAID-5 for
> update-intensive systems. Are there performance concerns with RAID-10 as
> well? We will be buying from Dell (done deal for reasons too complicated to
> go into) and the disks they're selling are 146 Gb. I can get up to 8 of them
> in the server we're buying. I asked them about just getting 2 big disks and
> going with RAID-1.
>
> My understanding is that with RAID-10, the system can do multiple reads and
> writes simultaneously so throughput is improved oversystems w/o RAID or with
> RAID-1. But the same logic would apply to RAID-5 only it doesn't work out
> that way.
>
> I just want to make sure I'm configuring this system correctly before I
> order it.
>
>
> --
> MySQL General Mailing List
> For list archives: http://lists.mysql.com/mysql
> To unsubscribe: http://lists.mysql.com/mysql?unsub=ekilimchuk@gmail.com
>
>


--
Best regards,

Eugene Kilimchuk

--0016e6d7eefa2ef02e0481ec8fc9--

Re: mysql & RAID

--0016367fa3de0195e60481ecc725
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

What are your plans for OS as this can have an impact on hardware choice
especially if you are considering Solaris or Open Solaris.

Regards
John

On Tue, Mar 16, 2010 at 3:22 PM, Евгений=
Килимчук wro=
te:

>
> http://assets.en.oreilly.com/1/event/27/Linux%20Filesystem%2 0Performance%=
20for%20Databases%20Presentation.pdf
>
> 2010/3/10 John G. Heim
>
> > Hi,
> >
> > I am working on configuring a new hardware database server. I'm a littl=
e
> > confused as to what to do about disk. We have several mysql databases b=
ut
> by
> > far the 2 most active are spamassassin bayesian rules and horde3/imp we=
b
> > mail. Both do a lot of updates. The bayesian rules are added to each ti=
me
> a
> > spam message comes in for any of our 200 users. And the horde3/imp writ=
es
> > address book updates and preferences quite often.
> >
> > I have read (and have been told) to stay away from RAID-5 for
> > update-intensive systems. Are there performance concerns with RAID-10 a=
s
> > well? We will be buying from Dell (done deal for reasons too complicate=
d
> to
> > go into) and the disks they're selling are 146 Gb. I can get up to 8 of
> them
> > in the server we're buying. I asked them about just getting 2 big disks
> and
> > going with RAID-1.
> >
> > My understanding is that with RAID-10, the system can do multiple reads
> and
> > writes simultaneously so throughput is improved oversystems w/o RAID or
> with
> > RAID-1. But the same logic would apply to RAID-5 only it doesn't work o=
ut
> > that way.
> >
> > I just want to make sure I'm configuring this system correctly before I
> > order it.
> >
> >
> > --
> > MySQL General Mailing List
> > For list archives: http://lists.mysql.com/mysql
> > To unsubscribe:
> http://lists.mysql.com/mysql?unsub=3Dekilimchuk@gmail.com
> >
> >
>
>
> --
> Best regards,
>
> Eugene Kilimchuk
>

--0016367fa3de0195e60481ecc725--