On 10/8/13 2:28 PM, Stefan Müller-Wilken wrote: > Dear all, > > I know, this is only in parts an OpenIndiana related questions but maybe > someone might share their experience / opinions... > > I have a customer running OI157_a8 on a Dell DL380-G7. Works like a charm and > everyone's happy. There's only one downside to the configuration and that's > the SmarArray P410i RAID controller. Crappy to use with ZFS as it can't be > run in JBOD mode. We had to configure it with 8 RAID0 logical volumes which > makes disk replacement a nightmare. Anyway, it's not a certified Oracle > configuration so you sometimes have to make compromises... > > Now a few weeks ago we received an Oracle T3-1 SPARC server in similar > configuration: 8 port SAS backplane, MegaRaid 9261-8i, fully equipped with 8 > disks. To my dismay I had to realize that as with the DL380 you *cannot* > switch of the LSI's RAID feature and while HP's SmartArray acucli is clumsy, > LSI's MegaCLI is just a joke. > > Our Oracle tech rep gave advice to configure the 8 disks in single drive > RAID0 and run them in RAIDZ but it seems that this is lose-lose: ZFS does not > live up to its potential in volume and fault management (e.g. not being able > to reliably switch to spares) and you still have to use MegaCLI to handle > failed drives. On the other hand, using a pure LSI RAID setup, I lose all ZFS > beauty. We were finally told that going for other controllers was no option > with SUN SGX-SAS6-INT-Z not being certified for the T3-1. > > Question now: what would you recommend? 8 LSI RAID0 LVs under ZFS, 8 drives > under LSI RAID-5, or switch to an Oracle certified controller with JBOD mode > (which one??)? Does it make sense to go for Soft RAID anyway, with that > configuration?
I do have a bunch of systems where I'm running ZFS on top of LSI HW RAID-1 for rpool. Works well enough for me with copies=2 and frequent scrubs (HW RAID takes care of device failures, copies=2 takes care of silent data corruption). Suboptimal, but since these are only boot pools and are otherwise untouched during normal operation, it was a tradeoff I was willing to make. As for HW RAID vs. JBOD on high-volume production, I'd definitely recommend going the single-drive RAID-0 route. Yes, disk replacement can be a PITA, but the performance and reliability tradeoffs are simply too good to give up. Cheers, -- Saso _______________________________________________ OpenIndiana-discuss mailing list [email protected] http://openindiana.org/mailman/listinfo/openindiana-discuss
