SDS and SAN Storage

Hi all what is possible and what is the best way to create chunks on a SAN- Storage (NetApp) for SDS. We are planning for IDS 11.50 database installations with SDS feature. OS will be LINUX (SLES or UBUNTU). As Storage we have a NetApp SAN. In case of cooked files (DIRECT_IO=1), which Filesytem has to be choosen ? How can we use raw devices over Fiber Channel ? Present a lun to all SDS-servers and use it as raw device ? Is it so simple or is something missing ? What is best practice to use NetApp-SAN-Storage over FiberChannel for Informix SDS-cluster ? TIA Ruediger Papke

On Aug 12, 8:21 pm, rpa <ruediger.pa...@t-online.de> wrote: > Hi all > > what is possible and what is the best way to create chunks on a SAN- > Storage (NetApp) for SDS. > We are planning for IDS 11.50 database installations with SDS feature. > > OS  will be LINUX (SLES   or UBUNTU). > > As Storage we have a NetApp SAN. > > In case of cooked files (DIRECT_IO=1), which Filesytem has to be > choosen ? > > How can we use raw devices over Fiber Channel ? > Present a lun to all SDS-servers and use it as raw device ? > Is it so simple or is something missing ? > > What is best practice to use NetApp-SAN-Storage over FiberChannel for > Informix SDS-cluster ? Hi Ruediger, Hard to say which is _the best_ way, you'll probably get as many different advices as the follow-up posts to your question :) Here is my take - yes, it is quite simple as you've already guessed: 1. Forget filesystems, go raw (Fibre Channel doesn't care) 2. Use RAID10 on your SAN, you'll get both performance and reliability 3. Assuming this will be OLTP engine, use 16kb (Linux = 2kb pages x8 a.k.a. big buffers) segment/stripe sizes on your SAN while configuring RAID10; for DSS go as big as you can 4. try to use all SAN controllers and HBA's on your host in active mode with alternating preferred paths for LUNs to achieve max throughput 5. carve out raw logical volumes on the host for Informix chunks; how many chunks? - highly debatable, we try to stick to the rule of thumb - 10 times more than physical disk drives in our SAN 6. ALWAYS use symbolic links for your chunks when adding them to Informix 7. don't complicate things with separate data and index dbspaces - RAID10 will spread the load for you; however, do follow the usual advices for rootdbs, physical and logical logs separation, makes life easier afterwards 8. enjoy the fact you're installing 11.50, you're not going to suffer long checkpoints problems even if you get something wrong :) Can't comment on SDS requirements, haven't been using SDS nodes yet. HTH Davorin