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We have an IBM 3HDD W2K server on RAID0. On Disk 1 has windows OS and Oracle OS. I want to config the oracle files as following:
Disk1: controlfile1, REDO files(1,2,3), datafile1, indexfile1
Disk2: controlfile2, UNDOTBS, datafile2, indexfile2
Disk3: controlfile3, TEMP tablespace, datafile3, indexfile3
Is this a good config? RAID level can not be modified or server reconfigured. Each HDD is 18G but space is not an issue. We are running 9.2.0.4.
RAID 0 is only good for files you can lose; ie. TEMP, software, etc. Putting datafiles on RAID 0 is BAD, BAD, BAD.Quote:
Originally posted by newbie5
We have an IBM 3HDD W2K server on RAID0. On Disk 1 has windows OS and Oracle OS. I want to config the oracle files as following:
Disk1: controlfile1, REDO files(1,2,3), datafile1, indexfile1
Disk2: controlfile2, UNDOTBS, datafile2, indexfile2
Disk3: controlfile3, TEMP tablespace, datafile3, indexfile3
Is this a good config? RAID level can not be modified or server reconfigured. Each HDD is 18G but space is not an issue. We are running 9.2.0.4.
Given that it has to be done and that it has to be done on RAID0:
- you should multiplex the REDO - have 3 files per group, one on each disk
- frequent backups
- run in ARCHIVELOG mode
- cherish your archlogs (copy them EVERYWHERE)
from what you say it seems that you are going to put datafiles in corresponding disks you are talking about, that confuses me, if it´s RAID-0 how can you have that control?
Ah! did he mean striping (RAID zero), or did he mean NO RAID (zero RAID)? I ASSumed the second . . . .
Yes. It is a NO RAID situation with C:, D: and E: drives. However, can I not have a RAID0 3HDD with 3 logical partitions C:, D and E:?
Why? What would be the point of 3 logical devices?
multiplexing? I realize that there will be no performance gain in I/O.
What happens if one of you disks goes bad? You lose all three filesystems.Quote:
Originally posted by newbie5
multiplexing? I realize that there will be no performance gain in I/O.
WOOOOHA . . .
Stop me when I go wrong:
You have three physical disks - let's call them 0, 1, 2.
You do not have a hardware RAID controller - or if you do, you aren't allowed to change the config.
The Win2K Disk Administrator sees three disks 0, 1, 2.
AFAIK at this point the only reason to "stripe" is for performance.
Oracle will multiplex Control and RedoLog files, but you only get full value of doing that if that each member of the "group" goes to a different physical disk.***
If you have logical drives (C: D: & E: ) striped across the physical disks, then most files will have blocks on all three disks and a disk failure will wreck them all.
*** Corrected following Tim Hall's post - see below.
. . . You could build a mirror at the OS level - not efficient.
(I only know Disk Adminstrator for NT - I guess Win2K is similar)
Something like:
Create partition on disk0 - format as C:
Create partition on disk1 - create mirror* on disk2 - format as D:
Put OS, software, pagefile and TEMP TS on C:
Put the rest of the db on D:
* (The help in Disk Administrator tells you how, under "Establish & Break Mirror Sets")
[wild idea] Still with OS mirroring: Create a 9Gb partition on all three disks. Mirror the partition on 0 into the free space on 1, partition on 1 into free space on 2, partition on 2 into free space on 0. I hate to think what the performance would be like! But you could lose a disk and still keep all the data. [/wild idea]
WHat about Raid 0,1 for this set up?
with 3 disks? how?
I think RAID 0 is very good in term of performance but bad for recovery purposes. That is depend on how critical your data is. It is recommended to mirror your online redo log files into 3 disk you have so that you won't face single-point-of-failure where one group of you redo log corrupted. Also saperate your datafile into 3 disk as well, this is for easy recovery and manageable datafile. There should be no perfomance issue if you put datafile on the different disk since you are running in RAID 0.
The best RAID for oracle to me is RAID 1+0 <- read/write performance + recoverable
Any difference between Raid 1,0 andQuote:
Originally posted by zainalj
The best RAID for oracle to me is RAID 1+0 <- read/write performance + recoverable
Raid 0,1..
Because I have been suggested for 0,1 for
3 hard disks of 18 gb and 1hard disk of 32 gb(18gb waste..?)
YOU CAN'T DO 0+1 WITH 3 DISKS!Quote:
Originally posted by engiri
Any difference between Raid 1,0 and
Raid 0,1..
Because I have been suggested for 0,1 for
3 hard disks of 18 gb and 1hard disk of 32 gb(18gb waste..?)
YOU CAN'T DO 0+1 WITH 3 DISKS!
YOU CAN'T DO 0+1 WITH 3 DISKS!
YOU CAN'T DO 0+1 WITH 3 DISKS!
YOU CAN'T DO 0+1 WITH 3 DISKS!
YOU CAN'T DO 0+1 WITH 3 DISKS!
YOU CAN'T DO 0+1 WITH 3 DISKS!
YOU CAN'T DO 0+1 WITH 3 DISKS!
YOU CAN'T DO 0+1 WITH 3 DISKS!
YOU CAN'T DO 0+1 WITH 3 DISKS!
IT IS NOT 3
IT IS 4
That will work.
marist89: "YOU CAN'T DO 0+1 WITH 3 DISKS!"
A: You can if they're magical pixie-disks :)
DaPi: "Oracle will multiplex Control and RedoLog files, but it is only worth doing that if you can be sure that each member of the "group" goes to a different physical disk."
A: Be careful! Someone might read this quote and stop multiplexing their files. It's an Oracle recommendation to multiple controlfiles and redologs even if you are using a single physical disk.
Cheers
Tim, I hang my head in shame. I've corrected the post. Tx.
YES,
YOU CAN DO 0+1 WITH 3 DISKS. but unfortunately not on the planet earth.
0+1 is different with 1+0 on how they work. 1+0 it's mirror first and sripe while 0+1 it's stripe first and mirror. To me it is better to use 1+0 - Just common sense.
Still can do 1+0 with 3 disks, but again not in the planet earth.. maybe in pluto can.
You cannot write 10 times (again):Quote:
Originally posted by marist89
YOU CAN'T DO 0+1 WITH 3 DISKS!
YOU CAN'T DO 0+1 WITH 3 DISKS!
YOU CAN'T DO 0+1 WITH 3 DISKS!
YOU CAN'T DO 0+1 WITH 3 DISKS!
YOU CAN'T DO 0+1 WITH 3 DISKS!
YOU CAN'T DO 0+1 WITH 3 DISKS!
YOU CAN'T DO 0+1 WITH 3 DISKS!
YOU CAN'T DO 0+1 WITH 3 DISKS!
YOU CAN'T DO 0+1 WITH 3 DISKS!
YOU CAN'T DO 0+1 WITH 3 DISKS!
YOU CAN'T DO 0+1 WITH 3 DISKS!