SAN solution for SAP

[Former Member]

Hi everyone,

We have multiple SAP instances (ECC6(DEV and PROD), CRM, Portal) installed on various systems. and we have an issue with growing database size which the attached disks are not able to satisfy. we would like to move to SAN(storage area network) environment for better storage solution. Can anyone help me in this. i would need to know how this can be achieved.

and Do we need to use hardware which the SAP is certified to run on?

Thank you all,

Vinod.

[Former Member]

The cheaper solution :

consider to use iSCSI interface (SCSI over ethernet)

[andrew_shen]

Hi Vinod,

I'm not sure if there is certificate for SAN hardware.

Basically, SAN included the following...

--- Controller card (usually have TWO), cache and CPU inside

--- The HDD enclosure, may have more that one, connect to controller

--- Backup Battery, backup cache data in case of power failure

--- a few Interface Port for Server to connect, SAN allow more that ONE server to connect and the Interface port will never enough, you needed a SAN switch (or two, to eliminate single point of failure)

On server(s), a interface card (HBA) is used to connect to the SAN controller, you can install more than one to eliminate single point of failure, and a RDAC driver is needed.

Software tools is then used to config HDD on SAN to difference RAID level (Array), and then you can create Logical Drive and assign to hosts (server).

For example...

--- 11 x 146GB form an Array A by RAID 5, Array A will have total 1460GB

--- Logical A (1000GB) and Logical B (460GB) is created on Array A

--- assign logical A & B to Host A

--- Host A will see two HDD and sized in 1000GB and 460GB

(*overhead not calculated)

--- if any ONE of the HDD in Array A fail, Logical A & B still function without error

--- if TWO HDD in Array A fail, both logical A & B fail

So for fast recovery, we usually put Hot spare HDD in SAN, when ever a HDD fail, Hot spare HDD is used to rebuild the Array.

Some of the factors you should consider...

1) Performance! Performance!! Performance!!! consider the bandwidth from controller to HDD enclosure, the HDD technology (e.g. no SATA HDD for database), the Enclosure technology (chain or switch?), the controller cache size (but not always the more the better), the bandwidth to host, the max number of HDD that form a array, the sector size, etc...

2) If any of the Enclosure loss, my data loss? e.g. will my data lost if any of the enclosure lost power?

3) the power consumption

4) Path for upgrade and expanding

Hope the information helps, and please forgives my pool writings 

Andrew