disk array versus jbod experiences

[Michael Murphy_2]

In the past I have had a lot of experience setting up jbod disk for oracle databases (stripping, mirroring, raw vs file system, lv creates). We are now acquireing a disk array (hitachi 9570), and it seems like most of that goes out the window (the array takes care of most of this for you?). Can anyone out their point to documentation/classes/webinars that might help to quickly fill in questions I have on how to set up this array (for Oracle)? Thanks...

[D Block 2 · Accepted solution]

The 'mirroring' which is done in S/W for JPOD is done on the array controller(s). As for 'stripping' and lv creates, will most likely continue w/ the hitachi array.

Hitachi does say a Raid 5, so you don't really have to worry about 'stripping'.

You will need more than one path (fibre) to the array from your HPUX server. The two fibre cables will most likely run into a Switch, which has multiple connections to the Array.

good luck

[Shaikh Imran]

Hi,
You will have a simple LUN ( Logical Unit Number ) Fundamentals while working with disk arrays.
The simple logic is you will get a software along with the array with which you can build a RAID of the available choice.
Each RAID will be given a LUN Number.These LUN's will be available to the HP-UX server and a single Disk with a device file say
/dev/dsk/c3t4d0.
Now you know very well what to do with this device files.

Yes to add on you will also have many performance boostings from the array side as it will have the option to increase,decrease the read-cache & write cache,with which you can configure the hardware to be used as per your software requirements.
If you application is read intensive then read cache should be set to high and vice-a-versa for write cache.

Regards

[Ted Buis]

Just remember that ultimately you have to write the informantion from cache to disk, so the number of spindles still count. The more spindles, the better the performance.
What server(s) do you plan to connect?

[Cass Witkowski]

I don't know if you have a choice of raid on the Hitachi. If you are doing a lot of disk writes then you may want to consider raid 1 (mirroring) versus raid 5. In a worse case scenario, every write on a raid 5 disk will require 2 reads and 2 writes. Caching in the disk controller will ameliorate some or most of this. Also consider when a disk fails in a raid 5 the performance hit you take reading data until the raid set is repaired