Hello, I have couple of questions regarding raid routine. 1> When i do mkraid, is there any specific routines in md.c that is responsible for adding and tracking the device. I have maintain the entries in /etc/raidtab. When i copy a file into the raid device, is there any specific routine that track the device to write the next block( raid 0 case). 2> Also the routine that keeps track the amount of buffer size that can be written to each particular device and the case when the writing to one disk fails. 3> Also i was wondering whether the source code of raid tools are availaible in linux directory. It would be great if somebody can throw some light. Thanks in advance. -Jay >===== Original Message From Neil Brown <neilb@cse.unsw.edu.au> ===== >On Wednesday July 30, jshankar@CS.ColoState.EDU wrote: >> Hello , >> >> I am Jayshankar, Masters student in Colorado State UNiversity. >> >> A small question on raid. >> >> Suppose i have got raid0 connected to disk1, disk2 , disk3 , disk4. >> >> The operating system writes a block of data to disk1 then to disk2, disk3, >> disk4. Do the I/O needs to be successful on disk1, for writing the next block >> of data on disk2, disk3, disk4. Or it checks the I/O is successful on disk1, >> after the block of data has been written to disk2,disk3,disk4. >> >> >> Looking forward for your reply. >> >> THanks in advance. >> >> -Jay > >Please send future questions to > linux-raid@vger.kernel.org >rather than to me personally. > >All disk IO in Linux is asynchronous. >i.e. submitting a block schedules it for IO. If you submit lots of >blocks they all get scheduled for IO. This is true whether your are >accessing a single device or a raid array. > >So there is no check for success of one block before writing the >next. quite often the blocks writen to the different drive will all >be written at one. > >NeilBrown - 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
