On Fri, Oct 18, 2013 at 09:04:55PM -0700, Chris Cappuccio wrote: > Darren Spruell [phatbuck...@gmail.com] wrote: > > I don't have a great deal of experience with SSD disks but was spec'ing > > some systems to use them. We'd be doing RAID on the hosts and I'd prefer > > to have something supported by bio(4) for volume management. Do SSDs > > have any impact on ability to do this? Or can one use the same HW RAID > > controllers for volume management and bio(4) doesn't have to deal with > > any differences? Or do SSDs typically require special RAID controllers? > > > > Looking at Dell R420s and hoping the PERC controller + SSD combination > > will work under bio(4) (although knowing precisely the driver/controller > > would be necessary, I realize). > > SSDs mimic the same interface of any hard disk, bioctl doesn't treat them > any differently than any other disk. > > Using them in RAID isn't typically the best idea, if you are worried > about write failures bringing the disks to a halt. At least, some failure > modes will affect all SSDs *at the same time* in a RAID configuration > because the SSDs all receive a similar number of write requests and data. > > If the softraid develops TRIM support then you'll get better write performance > (although if I'm reading right, some modern SSDs use tricks to minimize the > need for TRIM?)
Yes, the modern SSDs run periodic tasks to reduce the impact of the lack of TRIM support and to enhance the speed. > > I waited until, uhh, now just to use SSDs in server applications. And I'm > still only counting on them lasting for 2 or 3 years > -- Juan Francisco Cantero Hurtado http://juanfra.info
