Solaris 11 , UFS or ZFS ?

Hi, My customer going to migrate from a Solaris 10 virual zone UFS-file system to Solaris 11, they use Informix 12.10.FC15. There is a suggustion to use the ZFS for the new machine, but Iam not sure what dose that mean for the database, I wonder if anybody know which one of those file system work best with Informix ? Best Regards /Layth ------------------------------ Layth Yousif ------------------------------ #Informix

Layth: Here are my notes on ZFS from my presentation at the 2019 IIUG Conference: ZFS – Sun developed for Solaris and released as open source Uses copy-on-write transaction model – rewrites are made to a different physical location than data came from and the new block replaces the old one in the meta-data and are later "cleaned" by background threads. This causes chunks to become more and more non-contiguous over time. IDS pages are substantially smaller than ZFS pages. That means many rewrites of the same ZFS page and many relocations that have to be cleaned up in the background which affects performance. Dirty block cleanup eats into IO bandwidth and fights applications for head positioning ZFS maintains two to three checksums for every data and meta-data block modifying each up the meta-data tree for every write High overhead Good safety In addition, note that when applied to SSD drives the multiple copy-on-writes happening due to the disparity between Informix pages and ZFS "pages" will reduce the lifespan of these drives as each "cell" on the drive has a lifespan limited by the number of times it is written to. ZFS and UFS under Solaris are both meta-data only journaled filesystems. Because of the tree structure and multiple checksums (as mentioned above) ZFS journaling is fairly high overhead. UFS journaling is lower overhead. Neither is likely to have a major impact on Informix performance overall except during chunk extension or new chunk/dbspace allocation. Chunk allocation and extension under ZFS is fairly slow compared to other filesystems. If you use ZFS it will be important to keep up with dbspaces filling and be proactive to add space. If you rely on the storage pools and automatic chunk extension for space management, it will be important to set high thresholds to trigger automated chunk allocation and chunk extension. Less so with UFS. Metadata journaling is not important to the safety of Informix storage mainly because, except for the occasional chunk extension or new allocation, the metadata of a filesystem dedicated to Informix is fairly static. Art ------------------------------ Art S. Kagel, President and Principal Consultant ASK Database Management Corp. www.askdbmgt.com ------------------------------

Hi Art, thanks a lot for a very detailed answer, I think I will choose the UFS, Best Regards //Layth ------------------------------ Layth Yousif ------------------------------