Hello Neil/Rob, I am using IP based network(2 Intel Ethernet card Pro 1000/T). CPUinfo is as below : processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 8 model name : Pentium III (Coppermine) stepping : 1 cpu MHz : 526.186 cache size : 256 KB fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 2 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 mmx fxsr sse bogomips : 1044.22 Can u please explain me about the below fuctionality: 2>If my chunk size is 8 byte. Does that mean it will write 8 byte into device 0 and then into device 1. Is the write request to the disk in synchronous or asynchronous mode. 3> Is wite_disk_sb in md.c responsible for writing into disk??. Is fsync_dev responsible for synhronous write ??. If so can i change to asynchronous write.I will really appreciate if somebody can tell me what all routines I need to go through to figure out the functionality of raid0 behaviourand how it write to disk. Thanks Jay ===== Original Message From rob <rob@fantinibakery.com> ===== >Hello, > What kind of network are you uasing for the data transfer? > > The rest of post does not answer your specific questions, but is to >show the transfer speeds on our network to backup servers using hardware >and software raid. > > Both systems use Mandrake 9.1. network is a fast-lan. speed 100. > >Bkup1 is scsi with Mylex hardware raid, athlon 1800 cpu. array has 4 >9-gb lvd disks. > >Bkup2 is a new test server using software raid. dual 750 intel xeon, >4- 9-gb se scsi disks. > > I transfer data 30-40 times per day to each server. 500-mb hourly on >the average. ususal tme is less than a min. > The test uses rsync to transfer data. rsync uses a lot of cpu so the >speed difference may be more due to cpu than the difference of raid type. > > the command used: rsync -e ssh -a --stats /bkup3/ fbc5:/bkup3/ > >here is the result of sending approx 3-gb of data to each: > >------------------------------------------------- > this is the output of an rsync transfer to the backup software-raid server: > >Mon Oct 13 07:36:41 EDT 2003 >rsync[21832] (sender) heap statistics: > arena: 7996056 (bytes from sbrk) > ordblks: 59 (chunks not in use) > smblks: 2 > hblks: 1 (chunks from mmap) > hblkhd: 516096 (bytes from mmap) > usmblks: 0 > fsmblks: 80 > uordblks: 7821736 (bytes used) > fordblks: 174320 (bytes free) > keepcost: 128840 (bytes in releasable chunk) > >Number of files: 65699 >Number of files transferred: 45739 >Total file size: 2707740663 bytes >Total transferred file size: 2707630760 bytes >Literal data: 2707630760 bytes >Matched data: 0 bytes >File list size: 1,925,417 >Total bytes written: 2,711,680,565 >Total bytes read: 731844 > >wrote 2711680565 bytes read 731844 bytes 5,046,348.67 bytes/sec >total size is 2707740663 speedup is 1.00 >Mon Oct 13 07:45:38 EDT 2003 > >------------------------------------ >to the hardware raid server: >Mon Oct 13 07:23:19 EDT 2003 >rsync[19963] (sender) heap statistics: > arena: 7996056 (bytes from sbrk) > ordblks: 59 (chunks not in use) > smblks: 2 > hblks: 1 (chunks from mmap) > hblkhd: 516096 (bytes from mmap) > usmblks: 0 > fsmblks: 80 > uordblks: 7821736 (bytes used) > fordblks: 174320 (bytes free) > keepcost: 128840 (bytes in releasable chunk) > >Number of files: 65699 >Number of files transferred: 45739 >Total file size: 2707740663 bytes >Total transferred file size: 2707630760 bytes >Literal data: 2707630760 bytes >Matched data: 0 bytes >File list size: 1925417 >Total bytes written: 2,711,680,565 >Total bytes read: 731844 > >wrote 2711680565 bytes read 731844 bytes 8,384,582.41 bytes/sec >total size is 2707740663 speedup is 1.00 >Mon Oct 13 07:28:42 EDT 2003 > > >---------------- > > > >Jayshankar Nair wrote: > >>Hello, >> >> >>I was testing the raid0 configuration for the iscsi device ( /dev/sdb and >>/dev/sdc). >> >>For writing a 512MB in a LAN environment it was taking 24 hrs. i was going >>through the source code of raid0.c and certain things doesn't made sense to me. >> >>1> what role does the Hash bit play. >>2>If my chunk size is 8 byte. Does that mean it will write 8 byte into device 0 >>and then into device 1. Is the write request to the disk in synchronous or >>asynchronous mode. >> >> >>3> Is wite_disk_sb in md.c responsible for writing into disk??. Is fsync_dev >>responsible for synhronous write ??. If so can i change to asynchronous write.I >>will really appreciate if somebody can tell me what all routines I need to go >>through to figure out the functionality of raid0 behaviour. >> >>Thanks >>Jayshankar >> >>- >>To unsubscribe from this list: send the line "unsubscribe linux-raid" in >>the body of a message to majordomo@vger.kernel.org >>More majordomo info at http://vger.kernel.org/majordomo-info.html >> >> > >- >To unsubscribe from this list: send the line "unsubscribe linux-raid" in >the body of a message to majordomo@vger.kernel.org >More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
