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Hey all... Does anyone here have any experience with running DB2 on a
NetApp filer (storage)? If so, what volumes did you use (how many disks
per volume).

For those who do not know what a Netapp Filer is:
It's a storage device created by a select group of Cisco employees.
It connects to a server using NAS or iSCSI.
What makes it different from other networked storage arrays is that it
has a x GB buffer for writes. So for the database write to it, it seems
that it's performing writes on a Ramdisk. In the buffer, data is
preformatted in Raid4 order and than flushed to disk.

reads are performed buffered from the raid-4 array.

We're planning on using such a device for storing data, and I was
curious if anyone has had any positive or negative experiences with such
a setup.

Note: I already read a few best-practice papers, but I'd like to know
from real people in real situations how it performs.

We're using DB2 for a lot of small concurrent transactions.

-R-

Jurgen Haan wrote:
> Hey all... Does anyone here have any experience with running DB2 on a
> NetApp filer (storage)? If so, what volumes did you use (how many disks
> per volume).
>
> For those who do not know what a Netapp Filer is:
> It's a storage device created by a select group of Cisco employees.
> It connects to a server using NAS or iSCSI.
> What makes it different from other networked storage arrays is that it
> has a x GB buffer for writes. So for the database write to it, it seems
> that it's performing writes on a Ramdisk. In the buffer, data is
> preformatted in Raid4 order and than flushed to disk.
>
> reads are performed buffered from the raid-4 array.
>
> We're planning on using such a device for storing data, and I was
> curious if anyone has had any positive or negative experiences with such
> a setup.
>
> Note: I already read a few best-practice papers, but I'd like to know
> from real people in real situations how it performs.

I've used NetApps at a few different customer sites. A couple of
things:

1) Assuming you're using it as a NAS (with SMB or NFS), make *sure* you
have the appropriate patches on your database server. Work with
NetApp to find the latest suggested patch levels.

2) Make sure you have sufficient, dedicated network bandwidth between
the database server and the Filer. If you are thinking about using
Etherchannel (bonding multiple individual network connections into
1 virtual connection), make sure you understand your vendor's
implementation of Etherchannel before going down this path.

3) Volumes configuration: I've only worked on Filers for business
intelligence applications (tuning for read performance), so I'm not
sure if my experience is applicable to an OLTP environment.

However, we got good performance using 11+P RAID groups, and even
better performance when we combined multiple RAID groups into a
single volume (i.e. the volumes we were using had 3 11+P RAID
groups).

For OLTP, I suspect you may find that you have better experience
using multiple volumes, each built on separate, smaller (5+P) RAID
groups.




Good luck,

Ian wrote:
>
> I've used NetApps at a few different customer sites. A couple of
> things:
>
> 1) Assuming you're using it as a NAS (with SMB or NFS), make *sure* you
> have the appropriate patches on your database server. Work with
> NetApp to find the latest suggested patch levels.

Well... iSCSI has crossed my mind
Are there any signifigant performance differences between iSCSI and NAS?


>
> 2) Make sure you have sufficient, dedicated network bandwidth between
> the database server and the Filer. If you are thinking about using
> Etherchannel (bonding multiple individual network connections into
> 1 virtual connection), make sure you understand your vendor's
> implementation of Etherchannel before going down this path.

I was thinking of trunking the 2 1Gbit channels into 1 2Gbit.
What use is a fast storage solution if you use a poor connection.


> 3) Volumes configuration: I've only worked on Filers for business
> intelligence applications (tuning for read performance), so I'm not
> sure if my experience is applicable to an OLTP environment.
>
> However, we got good performance using 11+P RAID groups, and even
> better performance when we combined multiple RAID groups into a
> single volume (i.e. the volumes we were using had 3 11+P RAID
> groups).

Ah... this is very useful information.

> For OLTP, I suspect you may find that you have better experience
> using multiple volumes, each built on separate, smaller (5+P) RAID
> groups.
>

Thank you for your detailed response, I will certainly keep it in mind.

-R-

Jurgen Haan wrote:
> Ian wrote:
>
>>
>> I've used NetApps at a few different customer sites. A couple of
>> things:
>>
>> 1) Assuming you're using it as a NAS (with SMB or NFS), make *sure* you
>> have the appropriate patches on your database server. Work with
>> NetApp to find the latest suggested patch levels.
>
>
> Well... iSCSI has crossed my mind
> Are there any signifigant performance differences between iSCSI and NAS?

There should be pretty significant performance differences. I haven't
used iSCSI, but iSCSI is a method for attaching the storage directly to
your server, like Fibre Channel, SATA.

NAS is a fileserver on your network that you connect to using TCP/IP
protocols like NFS or SMB.

>> 2) Make sure you have sufficient, dedicated network bandwidth between
>> the database server and the Filer. If you are thinking about using
>> Etherchannel (bonding multiple individual network connections into
>> 1 virtual connection), make sure you understand your vendor's
>> implementation of Etherchannel before going down this path.
>
>
> I was thinking of trunking the 2 1Gbit channels into 1 2Gbit.
> What use is a fast storage solution if you use a poor connection.

Again, I can't speak to iSCSI, but it is probably different than normal
ethernet.

Generally I have found that when using Etherchannel, the particular NIC
within the trunk is selected based on the destination IP address.
Therefore, if all traffic is going to 1 IP address (i.e. the NAS
server), then all traffic goes through one interface. Etherchannel
does have a different routing mechanism (round-robin), but using it
has never resulted in performance gains you might expect.

Ian wrote:
>
>
> Generally I have found that when using Etherchannel, the particular NIC
> within the trunk is selected based on the destination IP address.
> Therefore, if all traffic is going to 1 IP address (i.e. the NAS
> server), then all traffic goes through one interface. Etherchannel
> does have a different routing mechanism (round-robin), but using it
> has never resulted in performance gains you might expect.
>

iSCSI is a fairly new method with both the advantages of NAS and SAN
combined. It uses stock Ethernet components to tunnel SCSI blocks
through TCP/IP. In a linux environment you can use special Kernel
modules to transform a NIC into a HBA. But I don't know whether both the
linux kernel as well as the netapp can trunk multiple connections, but
that's an issue I can address at the local netapp vendor.

How is your overall opinion on the netapp as DB2 storage?

Thanks

-R-

Jurgen Haan wrote:
> Ian wrote:
>
>>
>>
>> Generally I have found that when using Etherchannel, the particular NIC
>> within the trunk is selected based on the destination IP address.
>> Therefore, if all traffic is going to 1 IP address (i.e. the NAS
>> server), then all traffic goes through one interface. Etherchannel
>> does have a different routing mechanism (round-robin), but using it
>> has never resulted in performance gains you might expect.
>>
>
> iSCSI is a fairly new method with both the advantages of NAS and SAN
> combined. It uses stock Ethernet components to tunnel SCSI blocks
> through TCP/IP. In a linux environment you can use special Kernel
> modules to transform a NIC into a HBA. But I don't know whether both the
> linux kernel as well as the netapp can trunk multiple connections, but
> that's an issue I can address at the local netapp vendor.
>
> How is your overall opinion on the netapp as DB2 storage?
>
> Thanks
>
> -R-

From an Oracle standpoint NetApp is one of the best storage solutions
available. The one thing I would suggest you check out too is the
Apple Xserve RAID. They are faster than both NetApp and EMC, are
priced well below either, and mount on Linux.
--
Daniel A. Morgan
http://www.psoug.org
damorgan@x.washington.edu
(replace x with u to respond)

DA Morgan wrote:

>
> From an Oracle standpoint NetApp is one of the best storage solutions
> available. The one thing I would suggest you check out too is the
> Apple Xserve RAID. They are faster than both NetApp and EMC, are
> priced well below either, and mount on Linux.

Aha... Interesting device.
Thank you.

-R-