Ideal chunk auto extend size

Hello all! I'm playing with the idea of setting up chunk/dbspace auto extend, and I was wondering about a few things: Keeping in mind that Informix has a global auto extend policy, I was wondering: 1. What's the ideal starting size for an extendable chunk? 2. What's the ideal size for each auto extend? 3. How often can I check for dbspaces to be running out of space?/How taxing is this check on the database? 4. How fast is the chunk extend process? Is it be comparable to dd? I appreciate your help in advance! Cheers! Ramon Rey IDS: 11.70.FC9 on RHEL 7.5 (Maipo). Box: Virtual machine (VMware) from an Disks: provided from SAN into the VM as XFS. Chunks: cooked files. Also IDS: 11.70.FC9 on SPARC Solaris 10 (SunOS 5.10). Box: Solaris zones from an Oracle Sun T4-2 Disks: provided from SAN into the zones as ZFS. Chunks: cooked files.

There is no real "ideal extend size". The default is 10,000K. The "best" extend size will depend on your needs. The built-in ph_task function that extends chunks is fairly low overhead.