On Thursday 01 April 2004 20:46, Ji Haitao wrote:
I create a MD having 100 targets with dmsetup. IO error occurs when I access the 100th target. My operation steps are :
1.#create md sh> dmsetup create vd1 dmtable1
2. #access the 100th target sh> dd bs=512 count=10 if=/dev/zero of=/dev/mapper/vd1 seek=51380224
#errors happen dd: writing `/dev/mapper/vd1': Input/output error 1+0 records in 0+0 records out
I ran your 100-target table on one of my systems. Did a dd of the entire device with no I/O errors. I'm running device-mapper.1.00.08 on a 2.6.5-rc3 kernel.
If I only have 99 targets in dmtable1, everything is OK when I access the 99th target. Why? If device-mapper can support more than 100 targets in 1 MD ?
The configuration of my Linux host is: CPU: P4 1.4G MEM: 512M Kernel: 2.4.21 device-mapper.1.00.05 dd (fileutils) 4.1.9
1.00.05 is a bit out-of-date. I'd suggest upgrading to device-mapper.1.00.09 (upgrade both the tools and the kernel patches) and see if the problem persists.