Bear in mind that enterprise SSDs are already write-leveled at a hardware level. The big optimization for filesystems with enterprise SSD is making sure that filesystem blocks are aligned with the same block structure as the SSD is using - for cheap SSDs that don't do write leveling, then there's a lot of CoW optimizations you can do. And you would still RAID your disks - write leveling is nice, but it doesn't handle the failure of a controller chip or something similar. So you're never going to get away from that. As far as the upgrade path, the lifespan is comparable for a "spinning rust" hard drive. Thanks, Matt ________________________________ From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Andrew Kerber Sent: Friday, May 01, 2009 10:18 AM To: dofreeman@xxxxxxxxxxx Cc: Oracle-L (oracle-l@xxxxxxxxxxxxx) Subject: Re: Solid State Drives I wrote an article in IOUG Select journal about Solid State. I really think Solid Statie is the coming thing. At this point, it is too expensive to put all your storage on SS, but if you put your popular tables on it, you can see substantial speed improvements. If they can resolve the write issue, I could see SS really helping to reduce pinging in RAC by making the IO to disk almost as fast as the IO to cache, thus reducing the required cache sizes and the pinging caused by that. Redo log would also be a good usage for SS, reducing the time to switch logs. Currently, the developers are centered on leveling the writing, that is making the level of writes the same across all portions of the SSD. That is showing promise in extending the life of the SS storage. Solaris is working on a major initiative in SSD, I dont know how that will be affected by their purchase by Oracle On Fri, May 1, 2009 at 9:09 AM, Freeman, Donald <dofreeman@xxxxxxxxxxx> wrote: Has anybody given any thought to where we are going as SSD's get cheaper and bigger? We've been going round and round at my shop with discussions about RAID, other disk allocation issues, fights over storage. I mean we seem to spend a lot of time on that issue. I saw that IBM is testing a 4 TB SSD. I was wondering if you'd have to mirror that, What kind of reliability we would be getting. No more RAID discussions? I've heard there is a finite number of times you can write to it. What's the upgrade path here? -- Andrew W. Kerber 'If at first you dont succeed, dont take up skydiving.'