What is block size in storage?
A block is the largest contiguous amount of disk space that can be allocated to a file and is therefore the largest amount of data that can be accessed in a single I/O operation. A subblock is the smallest unit of contiguous disk space that can be allocated. Files smaller than one block size are stored in fragments.
How does block size affect performance?
A larger block size results in fewer cached blocks. For a file system that contain files of many different sizes, the file system delivers better overall performance from selecting a larger block size, 4 MiB or greater, rather than a smaller one.
What is block size in DD?
The dd command reports on the number of blocks it reads and writes. The number after the + is a count of the partial blocks that were copied. The default block size is 512 bytes.
What is NTFS cluster size?
By default, the maximum cluster size for NTFS under Windows NT 4.0 and later versions of Windows is 4 kilobytes (KB). This is because NTFS file compression is not possible on drives that have a larger cluster size.
Why is block size important?
Why Does Block Size Matter? As mentioned prior, a block is how much storage payload is sent in a single unit. Throughput is the result of IOPS, and the block size for each I/O being sent or received. Since a 256KB block has 64 times the amount of data as a 4K block, size impacts throughput.
What is Oracle data block?
A data block is the smallest logical unit of data storage in Oracle Database. One logical data block corresponds to a specific number of bytes of physical disk space, for example, 2 KB. Data blocks are the smallest units of storage that Oracle Database can use or allocate.
Does block size matter on SSD?
In general increasing the cluster size to (but not beyond) the block size of the SSD will be beneficial. The loss (of course) is that you will start to lose space and as you mention, the $/GB of SSDs is much higher than magnetic media.
How to configure Oracle database logs on jfs/jfs2 file system?
If you are placing Oracle Database logs on a JFS2 file system, then the optimal configuration is to create the file system using the agblksize=512 option and to mount it with the CIO option. Before Oracle Database 12 c, Direct Input-Output and Concurrent Input-Output could not be enabled at the file level on JFS/JFS2.
What is the maximum block size for Oracle Database?
If Oracle Database is installed on a journaled file system, then the block size should be a multiple of the file system block size (4 KB on JFS, 16 KB to 1 MB on IBM Spectrum Scale (GPFS)).
What is DB_block_size in Aix?
On AIX, you can set the value of the DB_BLOCK_SIZE initialization parameter to between 2 KB and 32 KB, with a default of 4 KB. If Oracle Database is installed on a journaled file system, then the block size should be a multiple of the file system block size (4 KB on JFS, 16 K to 1 MB on GPFS).
How to enable direct input-output on jfs/jfs2 with Oracle Database 12 C?
With Oracle Database 12 c, you can enable Direct Input-Output and Concurrent Input-Output on JFS/JFS2 at the file level. You can do this by setting the FILESYSTEMIO_OPTIONS parameter in the server parameter file to SETALL or DIRECTIO. This enables Concurrent Input-Output on JFS2 and Direct Input-Output on JFS for all data file Input-Output.