Hi, I remember something like this years ago, the problem was solved by altering the network packet size. So have you checked out what the OS is doing network packet wise, I am thinking about the MTU settings to increase the packet size? But honestly my experience with this kind of rman problem and TSM. /TDPO is that you just keep adding channels until you get to a point where you can live with it! Regards Pete On 19 October 2013 15:29, tefetufe . <coskan@xxxxxxxxx> wrote: > Hi, > We are doing some backup restore tests on our brand new environment using > tivoli tdpo. > Using rman We are backing up 8TB uncompressed backup in the same campus > with 6 channels in 3 hours using 10Gb network and writing into VTL > > When we try to restore same backup from another location using 1Gb card > with 6 channels and same rman settings we are somehow limited with *16MB > /sec *per channel (our previous restores never hit this issue when DB was > runnin on solaris and 10G) > > No matter how many channels we run total throughput is increasing in linear > but per channel limit is still 16MB/sec > > I'm kind suspicious about this *16MB/sec *wall we are hitting. As we are > not even using whole network bandwidht. I expect we can go higher with less > channles but it is not the case. no matter what the number of channels are > it is always 16MB/sec > There is no hardware multiplexing > We already tried playin with tcpwindow size on tdpo settings and > BACKUP_TAPE_IO_SLAVES=TRUE > > > Database is 11.2.0.3 and using filesystem (veritas with cio) on Redhat 6 > > My real wonder is if anybody seen this limitation per channel at all > > > strace sample outpu > > % time seconds usecs/call calls errors syscall > ------ ----------- ----------- --------- --------- ---------------- > 94.33 0.418938 38 10943 5620 semtimedop > 3.16 0.014031 0 64380 times > 1.44 0.006395 1 10617 semctl > 0.81 0.003601 1 5442 io_submit > 0.26 0.001169 1 1396 io_getevents > 0.00 0.000000 0 168 getrusage > ------ ----------- ----------- --------- --------- ---------------- > 100.00 0.444134 92946 5620 total > > > perf sample output is like below. > > 56.27% oracle oracle [.] sxorcopychk > 21.92% oracle [kernel.kallsyms] [k] 0xffffffff8103ba4a > 2.29% oracle oracle [.] krbddoh > 1.22% oracle oracle [.] krbr1b1 > 0.98% oracle oracle [.] ksfvsubmit > 0.97% oracle oracle [.] ksliwat > 0.91% oracle oracle [.] krbr1b2 > 0.89% oracle oracle [.] krbrpr > 0.64% oracle oracle [.] kcbhcvbo > 0.53% oracle oracle [.] krbcdb > > > > Appreciate if anybody hit the same issue before > > > Regards > -- > -- > Coskan GUNDOGAR > > > > Email: coskan@xxxxxxxxx > Blog: http://coskan.wordpress.com > Twitter: http://www.twitter.com/coskan > Linkedin: http://uk.linkedin.com/in/coskan > > > -- > //www.freelists.org/webpage/oracle-l > > > -- Regards Pete -- //www.freelists.org/webpage/oracle-l