On Tuesday May 30, michael.theodoulou@xxxxxxxxx wrote: > Hello, > > I am trying to create a RAID5 array out of 3 160GB SATA drives. After > i create the array i want to partition the device into 2 partitions. > > The system lies on a SCSI disk and the 2 partitions will be used for > data storage. > The SATA host is an HPT374 device with drivers compiled in the kernel. > > These are the steps i followed > > mdadm -Cv --auto=part /dev/md_d0 --chunk=64 -l 5 --raid-devices=3 > /dev/hde /dev/hdi /dev/hdk > > Running this command notifies me that there is an ext2 fs on one of > the drives even if i fdisked them before and removed all partititions. > Why is this happening? The ext2 superblock is on the second 1K for the device. The only place that fdisk writes is in the first 512 bytes. So fdisk is never going to remove the signature of a an ext2 filesystem. > > In anycase i continue with the array creation This is the right thing to do. > > After initialization 5 new devices are created in /dev > > /dev/md_d0 > /dev/md_d0p1 > /dev/md_d0_p1 > /dev/md_d0_p2 > /dev/md_d0_p3 > /dev/md_d0_p4 > > The problems arise when i reboot. > A device /dev/md0 seems to keep the 3 disks busy and as a result when You need to find out where that is coming from. Complete kernel logs might help. Maybe you have an initrd which is trying to be helpful? > the time comes > to assemble the array i get the error that the disks are busy. > When the system boots i cat /proc/mdstat and see that /dev/md0 is a > raid5 array made of the two disks and it comes up as degraded > > I can then stop the array using mdadm -S /dev/md0 and restart it using > mdadm -As which uses the correct /dev/md_d0. Examining that shows its > clean and ok > > /dev/md_d0: > Version : 00.90.01 > Creation Time : Tue May 30 17:03:31 2006 > Raid Level : raid5 > Array Size : 312581632 (298.10 GiB 320.08 GB) > Device Size : 156290816 (149.05 GiB 160.04 GB) > Raid Devices : 3 > Total Devices : 3 > Preferred Minor : 0 > Persistence : Superblock is persistent > > Update Time : Tue May 30 19:48:03 2006 > State : clean > Active Devices : 3 > Working Devices : 3 > Failed Devices : 0 > Spare Devices : 0 > > Layout : left-symmetric > Chunk Size : 64K > > Number Major Minor RaidDevice State > 0 33 0 0 active sync /dev/hde > 1 56 0 1 active sync /dev/hdi > 2 57 0 2 active sync /dev/hdk > UUID : 9f520781:7f3c2052:1cb5078e:c3f3b95c > Events : 0.2 > > Is this the expected behavior? Why doesnt the kernel ignore /dev/md0 > and tries to use it? I tried using raid=noautodetect but it didnt help > I am using 2.6.9 Most be something else trying to start the array. Maybe a stray 'raidstart'. Maybe something in an initrd. > > This is my mdadm.conf > DEVICE /dev/hde /dev/hdi /dev/hdk > ARRAY /dev/md_d0 level=raid5 num-devices=3 > UUID=9f520781:7f3c2052:1cb5078e:c3f3b95c > devices=/dev/hde,/dev/hdi,/dev/hdk auto=partition > MAILADDR myemail@xxxxxxxxxxxx This should work providing the device names of the ide drives never change -- which is fairly safe. It isn't safe for SCSI drives. > > Furthermore when i fdisk the drives after all of this i can see the 2 > partitions on /dev/hde and /dev/hdi but /dev/hdk shows that no > partition exists. Is this a sign of data corruption or drive failure? > Shouldnt all 3 drives show the same partition information? No. The drives shouldn't really have partition information at all. The raid array has the partition information. However the first block of /dev/hde is also the first block of /dev/md_d0, so it will appear to have the same partition table. And the first block of /dev/hdk is an 'xor' of the first blocks of hdi and hde. So if the first block of hdi is all zeros, then the first block of /dev/hdk will have the same partition table. > fdisk /dev/hde > /dev/hde1 1 19457 156288352 fd Linux raid autodetect > > fdisk /dev/hdi > /dev/hdi1 1 19457 156288321 fd Linux raid > autodetect When you created the partitions in /dev/md_d0, you must have set the partition type to 'Linux raid autodetect'. You don't want to do that. Change it to 'Linux' or whatever. NeilBrown - 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
