I was going to say something similar I feel like the SSD drives read much "more" then the standard drive. Read Ahead/arge sectors could and probably does explain it.
On Thu, May 16, 2013 at 3:43 PM, Bryan Talbot <[email protected]>wrote: > 512 sectors for read-ahead. Are your new fancy SSD drives using large > sectors? If your read-ahead is really reading 512 x 4KB per random IO, > then that 2 MB per read seems like a lot of extra overhead. > > -Bryan > > > > > On Thu, May 16, 2013 at 12:35 PM, Keith Wright <[email protected]>wrote: > >> We actually have it set to 512. I have tried decreasing my SSTable size >> to 5 MB and changing the chunk size to 8 kb >> >> From: Igor <[email protected]> >> Reply-To: "[email protected]" <[email protected]> >> Date: Thursday, May 16, 2013 1:55 PM >> >> To: "[email protected]" <[email protected]> >> Subject: Re: SSTable size versus read performance >> >> My 5 cents: I'd check blockdev --getra for data drives - too high values >> for readahead (default to 256 for debian) can hurt read performance. >> >>
