assigning big storage and chunck into multiple file system best practises

[apple]

dear hpux guru,
i want to create 4 of 80GB file systems. from the san storage, do i need provision one disc of 320GB and create 4 file systems from that big disc? or i need to provision 4 LUN of 80GB and craete file system one by one? appreciate you can share the best practises to optimise the oracle write/read performance. hope to hear from you. thank you

[TTr]

I would do a little bit of both. I would create 2 LUNs with 2 volumes in each. (The term volume is more appropriate than filesystem, the filesystem is a file/directory structure that sits on the top of a volume).

There are other factors that apply here, array physical disks, other existing LUNs, expandability of LUN/volumes, array controller ownership of LUNs, i/o streams etc.

[George_Dodds]

How many Oracle instances will you be running, ie is it just the one instance accessing the four filesystems?

Also what exactly will these filesystems be used for?

If you are expecting a lot of read/writes for all 4 filesystems then i wouldnt put them all on one disk.

[apple]

dear hpux guru,
one instance accessing the four volume.
sorry, they required 20GB for each volume

these volume will be used for repository and as informed by application a lot of read/writes. sir, what is the best approach to optimise the performance.

hope to hear from you. thank you

[TTr]

If you need performance you have to sacrifice capacity. This is a fact with all disk arrays. To get increased i/o, you have to assign several drives for these 4 LUNs and dedicate these drives just to these 4 LUNS. Even with 73GB drives for perfromance LUNs you should assign anywhere between 8 - 12 drives. With raid10, you get up to 360GB of space but you would only use 80GB total. That's how it is, you want performance, you dedicate a lot of disks and use a very small percentage of their space and you do not share them with other servers.

[apple]

sir,
what do u mean by assigning more drives? drive enclosure? hope to hear from you. thank you

[TTr]

assigning more drives means using the physical disks (sometimes refered to as spindles) inside the disk array for one array group that is dedicated to your 4 LUNs. It does not matter if they come from a new enclosure or are in the existing enclosures of the disk array. And every SAN storage system has its own characteristics so if you are doing this yourself you need to become familiar with the disk array.

[Torsten.]

What array model we talk about?

Do you want to have all disks in a single VG?

[apple]

dear SAN gurus,
very interesting.

"assigning more drives means using the physical disks (sometimes refered to as spindles) inside the disk array for one array group that is dedicated to your 4 LUNs. It does not matter if they come from a new enclosure or are in the existing enclosures of the disk array"
but sir, how to control this thing? is that the initial configuration when our hp engineer set up the eva. normally when i create LUN, i choose the vraid 5 and the Preferred path/mode. appreciate you can teach how assign more drives.

What array model we talk about?
we are using hp eva 8100.

Do you want to have all disks in a single VG?
intend to, but afraid of the performance penalty with this configuration. sir, is that an ideal configuration?


hope to hear from you. thank you.