root@host [~]# fsck /home2fsck from util-linux-ng 2.17.2e2fsck 1.41.12 (17-May-2010)/dev/sdb1: clean, 6018617/91578368 files, 54524459/366284000 blocksroot@host [~]# fsck /home4fsck from util-linux-ng 2.17.2e2fsck 1.41.12 (17-May-2010)/dev/sdd1: clean, 8094369/91578368 files, 75999625/366284000 blocksfsck returns no errorroot@host [~]# lsof /home4root@host [~]# lsof /home2lsof returns no userroot@host [~]# mount/dev/mapper/VolGroup-lv_root on / type ext4 (rw,relatime,usrjquota=quota.user,jqfmt=vfsv0)proc on /proc type proc (rw)sysfs on /sys type sysfs (rw)devpts on /dev/pts type devpts (rw,gid=5,mode=620)tmpfs on /dev/shm type tmpfs (rw,rootcontext=system_u:object_r:tmpfs_t:s0)/dev/sda1 on /boot type ext4 (rw)/dev/mapper/VolGroup-lv_home on /home type ext4 (rw,relatime,usrjquota=quota.user,jqfmt=vfsv0)/dev/sdc1 on /home3 type ext3 (rw,relatime)none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)/usr/tmpDSK on /tmp type ext3 (rw,noexec,nosuid,loop=/dev/loop0)/tmp on /var/tmp type none (rw,noexec,nosuid,bind)sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)root@host [~]# iostat -xkLinux 2.6.32-279.19.1.el6.x86_64 (host.buildingsuperteams.com)  01/06/2013      _x86_64_        (16 CPU)avg-cpu:  %user   %nice %system %iowait  %steal   %idle          18.91    0.02   39.17   20.22    0.00   21.67mount shows that there is sdd1 and sdb1 is not mountedDevice:         rrqm/s   wrqm/s     r/s     w/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await  svctm  %utilsda               0.16    11.93    1.35    3.30    53.91    59.92    48.95     0.10   21.87   3.70   1.72sdb               0.49   219.57   22.00   99.14   224.17  1275.44    24.76     7.44   61.38   7.45  90.24sdd               0.46   226.39   23.26   92.71   260.61  1277.34    26.52     0.67    5.77   7.71  89.40sdc               0.00     1.79    0.28    0.05     5.03     7.38    74.28     0.00   14.34   2.05   0.07dm-0              0.00     0.00    1.45   14.91    53.66    59.50    13.83     1.56   95.36   1.06   1.73dm-1              0.00     0.00    0.04    0.10     0.18     0.41     8.00     0.00   21.25   2.44   0.04dm-2              0.00     0.00    0.01    0.00     0.05     0.01     8.49     0.00    7.32   1.84   0.00iostat report huge writesWhat would the reason be? I will replace the hard disk anyway. But this puzzles me to no endThis caused a server crash already. I unmout the drive.iostat -x 1 shows empty, which is what's expected. So all this time I saw past data?
iostat report huge writes to drives that's not even mounted
io;fsck;lsof
It is possible your VolGroup-lv_root is created on that drive. Check output of following commandpvsIt display physical volumes information about LV.More info about LVM (1), (2), (3)