First, find the block size of your filesystem. On Linux, the default block size for an ext3 filesystem will be 4096 bytes (4 KB):
[root@firestorm ~]# tune2fs -l /dev/datavg/eclipse tune2fs 1.39 (29-May-2006) Filesystem volume name: /u2/eclipse Last mounted on: Filesystem UUID: 996f19ea-80da-477d-b961-2873ebe8181b Filesystem magic number: 0xEF53 Filesystem revision #: 1 (dynamic) Filesystem features: has_journal ext_attr resize_inode dir_index filetype sparse_super large_file Default mount options: (none) Filesystem state: clean Errors behavior: Continue Filesystem OS type: Linux Inode count: 1310720 Block count: 5242880 Reserved block count: 262144 Free blocks: 2651137 Free inodes: 1125318 First block: 0 Block size: 4096 Fragment size: 4096 Reserved GDT blocks: 1022 Blocks per group: 32768 Fragments per group: 32768 Inodes per group: 8192 Inode blocks per group: 512 Filesystem created: Fri Sep 23 22:04:10 2011 Last mount time: Mon Jan 9 13:03:16 2012 Last write time: Tue Jan 17 13:41:40 2012 Mount count: 8 Maximum mount count: 20 Last checked: Fri Sep 23 22:04:10 2011 Check interval: 15552000 (6 months) Next check after: Wed Mar 21 22:04:10 2012 Reserved blocks uid: 0 (user root) Reserved blocks gid: 0 (group root) First inode: 11 Inode size: 256 Journal inode: 8 Default directory hash: half_md4 Directory Hash Seed: e4114643-fdd7-446d-ae9c-4bdea1063657 Journal backup: inode blocks
Each UniVerse database file has its own setting for block size, which can be found by running the ANALYZE.FILE command from TCL, as in the example below:
>ANALYZE.FILE PRODUCT File name = PRODUCT File type = 18 File style and revision = 64BIT Revision 12 Number of groups in file (modulo) = 30427 Separation = 4 Number of records = 155092 Number of physical bytes = 70756352 Number of data bytes = 52605264 Average number of records per group = 5.0972 Average number of bytes per group = 1728.9008 Minimum number of records in a group = 2 Maximum number of records in a group = 7 Average number of bytes per record = 339.1875 Minimum number of bytes in a record = 176 Maximum number of bytes in a record = 2424 Average number of fields per record = 110.3191 Minimum number of fields per record = 108 Maximum number of fields per record = 194 Groups 25% 50% 75% 100% 125% 150% 175% 200% full
Multiply the separation by the filesystem block size for the database file block size. In this example, 4096 bytes * 4 = 16484 bytes (16 K).