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"Devices"

P: n/a
What is a "Device" in creating DMS tablespaces where the storage
subsystem is RAID 0 3 or 5 0, ie, heavily striped. I'm referring to an
array of 6 disks. One or several logical volumes can be created. Are
they handled by DB2 (8.2 Win WSE) as one device, or can I configure for
more than one device?

Nov 12 '05 #1
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P: n/a
Ian
Stanley Sinclair wrote:
What is a "Device" in creating DMS tablespaces where the storage
subsystem is RAID 0 3 or 5 0, ie, heavily striped. I'm referring to an
array of 6 disks. One or several logical volumes can be created. Are
they handled by DB2 (8.2 Win WSE) as one device, or can I configure for
more than one device?


Search the DB2 documentation for DB2_PARALLEL_IO - this parameter tells
DB2 that the container(s) for a tablespace exist on a RAID device and
allows DB2 to submit multiple IO requests in parallel to a single
container.

Nov 12 '05 #2

P: n/a
Stanley, it's 10:45 and I don't have anything better than surf!!!!
No, I'm going away tomorrow and I was just clearing stuff.

Devices are "raw devices" as opposed to "cooked devices" meaning formatted.
In Windoze, a path would look like D:\foo\bar
With Windoze 2000
1) If the whole drive is not partitioned:
Use \\.\PhysicalDrive x convention.
2) If drive is partitionned but none formatted
Use \\.\x convention for your contasiner
You're "raided" so handle your tablespaces as 1 container per array as
opposed to one container per physical read/write mechanism.

RAID 5 , 5 disks. Stripe 64K
Tablespace: Extent 16 pages of 4 k
Prefetchsize: 4 devices * 16 pages = 64k
In RAID 5, you loose 1/5th of each device for parity.

You should also look at Windows Globally Unique Identifiers GUID
HTH, Pierre.

--
Pierre Saint-Jacques
SES Consultants Inc.
514-737-4515
"Stanley Sinclair" <st*************@bellsouth.net> a écrit dans le message
de news: 11*********************@o13g2000cwo.googlegroups.c om...
What is a "Device" in creating DMS tablespaces where the storage
subsystem is RAID 0 3 or 5 0, ie, heavily striped. I'm referring to an
array of 6 disks. One or several logical volumes can be created. Are
they handled by DB2 (8.2 Win WSE) as one device, or can I configure for
more than one device?


Nov 12 '05 #3

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