On Tue, 2013-06-04 at 11:11 +0200, Per Jessen wrote:
Roger Oberholtzer wrote:
I am using XFS on a 12.1 system. The system records jpeg data to large files in real time. We have used XFS for this for a while since it has as a listed feature that it is well suited to writing streaming media data. We have used this for quite a while on openSUSE 11.2.
We have developed a new version of this system that collects more data. What I have found is that the jpeg data is typically written at the speed I expect. Every once in a while, the write takes 100x longer. Instead of the expected 80 msecs or so to do the compress and write, it takes, say, 4 or 5 seconds.
This may not be of much use to you, but we have a cctv system that also writes individual jpegs. They're only 640x480, but from a quick glance at the timing, writing one jpeg takes an average of 0.2ms (elapse). Very occasional jumps to maybe 20ms. The recording system is running 12.2 on a 2.8GHz Celeron with 1.5Gb RAM. I guess your jpegs are much bigger - otherwise it's a pretty significant difference. (oh, and we're using JFS, not XFS).
The disk system seems to maintain around 40-50M/sec sustained writes. Our images should be utilizing around 50% of that. I am trying this on some SSD disks with good old ext4. Just to have a point of comparison. Yours sincerely, Roger Oberholtzer Ramböll RST / Systems Office: Int +46 10-615 60 20 Mobile: Int +46 70-815 1696 roger.oberholtzer@ramboll.se ________________________________________ Ramböll Sverige AB Krukmakargatan 21 P.O. Box 17009 SE-104 62 Stockholm, Sweden www.rambollrst.se -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org