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Re: Oracle 9i Linux and raw devices

From: Andreas <ast1200_at_netscape.net>
Date: Sat, 12 Apr 2003 20:16:41 -0600
Message-ID: <3E98C889.1040007@netscape.net>

 >>Are you sure ?
 >>Currently Linux support up to 256 (255?) raw devices/system. If the limit
 >>would be 2GB/raw dev, it would create 512GB limit for entire database.
 >
 >
 > Nope. This is incorrect. Here is an excerpt from the "Database limits"
 > section in the "Reference" manual for 9.2:
 
***************************************************************************
 > Database files
 >
 > Maximum per tablespace
 >
 > Operating system dependent; usually 1022
 >
 > Maximum per database
 >

 > 65533
 >

 >
Mladen,
sorry, I didn't wrote it clear. THE MAX OF 256 RAW devices it's LINUX KERNEL LIMIT (the major num. for raw dev is only 8 bit), NOT ORACLE LIMIT.
 > Basically, lseek and ftell (the OS routines for postioning within files)
 > accept 64 bit arguments on 64-bit environments and 32 bit arguments on
 > 32-bit systems. The 1st bit is the sign and signfies the direction of the
 > movement (fwd/bckwd). The 32bit routines can be used to move within 
2GB files,
 > not larger. Unless you have things like ftell64 or lseek64 (64 bit env.),
 > you are stuck with the 2GB limit. I also have a bad experience with Slowaris 7
 > which claimed to be full 64 bits environment, but all my files over 2GB  > ended up being corrupted. The version was 8.0.5/6.

Yes, it's correct if create data files on a FORMATED FILES SYSTEM, but it work different on RAW DEVICE, the raw device isn't formated by the OS and each RAW device is a single data file.

It'a a fragment of Oracle documentation: "Oracle9iR2 on Linux: Performance,Reliability and Manageability Enhancements on Red Hat LinuxAdvanced Server 2.1"

...
64-bit File I/O
Linux supports 64-bit file I/O even on 32-bit platforms like Intel Pentiumbased
servers. Oracle9iR2 supports 64-bit file offsets internally, hence there are no 2GB or 4GB limitations on data, log and control files. The limits on number of files per database (64K), number of blocks per file (4 million), and
maximum block size (16KB) are common to other Oracle platforms. Based on these limits, the maximum size for a database file is 64GB, and the maximum database size with 16KB blocks is 4 petabytes. ...

is the raw device limit 4 PB?

Mladen Gogala wrote:
> On Sat, 12 Apr 2003 16:11:08 -0600, Andreas wrote:
>
>

>>Are you sure ?
>>Currently Linux support up to 256 (255?) raw devices/system. If the limit
>>would be 2GB/raw dev, it would create 512GB limit for entire database.

>
>
> Nope. This is incorrect. Here is an excerpt from the "Database limits"
> section in the "Reference" manual for 9.2:
> ***************************************************************************
> Database files
>
> Maximum per tablespace
>
> Operating system dependent; usually 1022
>
> Maximum per database
>
> 65533
> ***************************************************************************
>
>
>>If you are sure, please let me know where I can find reference for it.
>>I'm sure it's more then 2GB (If I'm wrong please give me a link to a ref.
>>doc.), but what is the limit on Linux IA32? I was no able to find any specs in
>>available for me docs.
>>
>>Thanks for respond,
>>-AST
>>
>>
>>Mladen Gogala wrote:
>>
>>>On Sat, 12 Apr 2003 10:55:01 -0600, Andreas wrote:
>>>
>>>
>>>
>>>>What is maximum size of datafile created on raw device (Linux IA32)?
>>>>
>>>>-AST
>>>
>>>
>>>2GB.
>>

>
> Here is the information from the "Database Limits" section in the 9.2
> reference book:
> ***************************************************************************
> Database file size
>
> Maximum
>
> Operating system dependent. Limited by maximum operating system file size;
> typically 2**22 or 4M blocks
> ***************************************************************************
>
> You could also look into the Note:107201.1 on the metablink.
>
> Basically, lseek and ftell (the OS routines for postioning within files)
> accept 64 bit arguments on 64-bit environments and 32 bit arguments on
> 32-bit systems. The 1st bit is the sign and signfies the direction of the
> movement (fwd/bckwd). The 32bit routines can be used to move within 2GB files,
> not larger. Unless you have things like ftell64 or lseek64 (64 bit env.),
> you are stuck with the 2GB limit. I also have a bad experience with Slowaris 7
> which claimed to be full 64 bits environment, but all my files over 2GB
> ended up being corrupted. The version was 8.0.5/6.
Received on Sat Apr 12 2003 - 21:16:41 CDT

Original text of this message

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