Ok, long story short. I had a single drive fail in my RAID5 array. I have already completed the process of removing the failed drive from the array, replacing it it with a new drive, and the array successfully rebuilt over night. Now I am wanting to run a fsck on /dev/md0 just as a precaution. However, I keep getting device or resource busy when trying to unmount:
I was able to successfully unmount the samba share I had at /export/media-raid.
After unmounting the Samba share, I went ahead and stop the smbd service.
What am I missing? Why can't I umount the raid md0 device or /mnt/raid? I have done this once before after a power outage but didn't document it at the time. I need to ensure everything is unmounted so I can run fsck on the /dev/md0 I believe.
My RAID 5 array contains 4 x 2TB drives and looks like this:
sudo mdadm cat /proc/mdstat
sudo mdadm --detail /dev/md0
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid5 sdc1 sdd1 sde1 sdb1
5860540224 blocks level 5, 64k chunk, algorithm 2 [4/4] [UUUU]
mdadm: metadata format 00.90 unknown, ignored.
Version : 00.90
Creation Time : Thu Mar 1 21:56:54 2012
Raid Level : raid5
Array Size : 5860540224 (5589.05 GiB 6001.19 GB)
Used Dev Size : 1953513408 (1863.02 GiB 2000.40 GB)
Raid Devices : 4
Total Devices : 4
Preferred Minor : 0
Persistence : Superblock is persistent
Update Time : Fri Mar 8 11:09:19 2013
State : clean
Active Devices : 4
Working Devices : 4
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 64K
UUID : 2068b124:43ab2872:50b15dd6:9583be21
Events : 0.6543
Number Major Minor RaidDevice State
0 8 17 0 active sync /dev/sdb1
1 8 33 1 active sync /dev/sdc1
2 8 49 2 active sync /dev/sdd1
3 8 65 3 active sync /dev/sde1
Any help is appreciated. I just want to run a filesystem check to make sure all is good after replacing the failed drive. Thanks in advance.