RE: Disk configuration

From: Kevin Lange <kgel_at_ppoone.com>
Date: Wed, 20 Jun 2001 15:02:19 -0700
Message-ID: <F001.00330E22.20010620144121@fatcity.com>

We
could do something simular to that on AIX by actually mapping blocks. Using SMITTY and the disk management section, we could create file system on specific areas of the drives. It would them be up to us to put files in the correct file system. I do not see why it would not be possible. Although the administration would seem to be a nightmare.

I
would think you could create your file system in the location you want. Then create the appropriate data files on that file system.

-----Original Message-----From: KC [mailto:kchan_at_speednet.com.au]Sent: Tuesday, June 19, 2001 7:51 PMTo: Multiple recipients of list ORACLE-LSubject: Re: Disk configuration
 Kevin,

 Thanks for your input. I was trying to put certain datafiles on contiguous disk space, tell me if I am wrong, I try to avoid the situation where you want to create a 2G file, but the file system don't have a 2G contiguous space, so your flle is broken into multiple pieces, can that happen??

 KC
 <BLOCKQUOTE
 style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid"> -----Original Message-----From:
 Kevin Lange <<A
 href="mailto:kgel_at_ppoone.com">kgel_at_ppoone.com>To: Multiple recipients of list ORACLE-L <<A
 href="mailto:ORACLE-L_at_fatcity.com">ORACLE-L_at_fatcity.com>Date: Wednesday, June 20, 2001 1:22 AMSubject: RE: Disk configuration
 It
 all depends on what kind of os/filesystem/and disks you have. I know that under AIX, using SSA drives we could actually tell where on the disk we wanted the filesystem to go. This way we could position certain things in the faster location.

But personally, I would not go thru the trouble.

 I
 have never had a DB slowdown so far because of placement on the drive. Admittadly, I have had probelms based on putting conflicting tables/indexes on the same drive .... you want to keep things that could be access simultaneously on different media. But other than that .... no other conflicts.

      <FONT face=Tahoma 
      size=2>-----Original Message-----From: KC 
      [mailto:kchan_at_speednet.com.au]Sent: Tuesday, June 19, 2001 9:36 
      AMTo: Multiple recipients of list ORACLE-LSubject: 
      Disk configuration
      Dear List,
       
      Someone told me when a disk 
      receive a write request, it write to the nearest free space on disk where 
      the disk read/write head is currently positioning, is this information 
      correct?? If this is true, is this a bad thing for database application?? 
      That mean we can't really control where the file go, for performance 
      purpose we may want to put certain files on the outer tracks of a disk, if 
      the write location is depending on where the read/write head is, how can 
      we avoid that, can we create subdisks from the outer track of a disk and 
      create a logical volume from it??
       
      <FONT face=Arial color=#000000

size=2>KC Received on Wed Jun 20 2001 - 17:02:19 CDT