On Sat, Dec 03, 2011 at 10:45:42AM +1300, Mark wrote: > On 3/12/2011 9:34 a.m., Per Sjoholm wrote: > >On 12/02/2011 07:44 PM, Gary Mills wrote: > >>On Thu, Dec 01, 2011 at 08:59:48AM -0600, Gary Mills wrote: [...] > >>>To begin, I'm using a single 1 TB SAS disk on the server, without log > >>>or cache devices. I intend to add an Intel 311 SSD for the log and > >>>Intel 320 SSDs for the cache. I'd like to ensure that these improve > >>>NFS performance. I'd like CIFS and zfs send performance to be > >>>reasonable as well. > > > The simple answer is, they can help, but I doubt you will see much > improvement with a single disk, since that is the major bottleneck.
I do need three more Seagate ST31000424SS disks. They were one to a customer, but now they seem to have disappeared from the market with no replacement. > The standard disk i/o performance guidelines like spindle count and > rpm still apply. > > Read cache is only useful if the same file or data is being read > multiple times, since the cache needs to be populated. > > For writes, if the server has plenty of memory and a zpool with an > optimal spindle count is as fast as an ssd, then it won't give as > much benefit, although it does have the benefit of being > non-volatile. > I seem to recall mention that the dedicated zil is only used if it's > needed. It's needed for synchronous writes, which will be a bottleneck for NFS. That's why I wanted to be certain that my SSD log device improved performance. > I have great performance from a FC target using 3 x SAT2-MV8 and 20 > x 2Tb sata disks without an ssd zil. -- -Gary Mills- -refurb- -Winnipeg, Manitoba, Canada- _______________________________________________ OpenIndiana-discuss mailing list [email protected] http://openindiana.org/mailman/listinfo/openindiana-discuss
