I don't understand your question. Please elaborate. This may help. It was sent by Mark Hahn, Feb 2004. I snipped the stuff not related to you. ---snip--- > [hahn@hahn hahn]$ cat /proc/sys/vm/bdflush > 30 500 0 0 500 3000 60 20 0 > > Value Meaning > nfract Percentage of buffer cache dirty to activate bdflush > ndirty Maximum number of dirty blocks to write out per wake-cycle > dummy Unused > dummy Unused > interval jiffies delay between kupdate flushes > age_buffer Time for normal buffer to age before we flush it > nfract_sync Percentage of buffer cache dirty to activate bdflush > synchronously > nfract_stop_bdflush Percetange of buffer cache dirty to stop bdflush > dummy Unused > > > in theory, this means: > - wake up bdflush when 30% of buffers are dirty. > - write up to 500 blocks per wakeup. > - 5 seconds between wakeups. > - let a buffer age for 30 seconds before flushing it. > - if 60% of buffers are dirty, start throttling dirtiers. > - stop bdflush when < 20% of buffers are dirty. ---snip--- Guy -----Original Message----- From: linux-raid-owner@xxxxxxxxxxxxxxx [mailto:linux-raid-owner@xxxxxxxxxxxxxxx] On Behalf Of Srinivasa S Sent: Thursday, December 23, 2004 2:05 AM To: linux-raid@xxxxxxxxxxxxxxx Subject: a minor query - please help I have configured a 3 disk raid5 on my linux system (fedora core 1 running 2.6.5-1.358 OS). I am basically trying to alter the RMW method a bit, which I think might improve performance. Multiple writes come to a stripe at the same time. Here is the output of the debug stmts I've put in raid5.c code: ----- Dec 23 11:16:01 raider kernel: check 2: state 0x4 read 00000000 write 2456be00 written 00000000 Dec 23 11:16:02 raider kernel: check 1: state 0x1 read 00000000 write 00000000 written 00000000 Dec 23 11:16:02 raider kernel: check 0: state 0x4 read 00000000 write 41fc8440 written 00000000 Dec 23 11:16:02 raider kernel: locked=0 uptodate=1 to_read=0 to_write=2 failed=0 failed_num=0 ----- Is there any method by which I can make only one write go through at a time? I'd be glad if any of you could reply to this... Regards, Srinivasa S - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx 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@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
