The filesystem corruption on iSCSI LUN on the Oracle Linux 7
Applies to
- ONTAP
- Oracle Linux 7
- Red Hat Enterprise Linux 7
- SAN
Issue
Remapping LUNs to a different LUN-ID/SCSI-ID without rescanning SCSI bus on the host can cause data corruption
Original mapping:
::> lun mapping show
Vserver Path Igroup LUN ID Protocol
---------- ---------------------------------------- ------- ------ --------
svm_linux /vol/vol_linux/lun1 linux_iscsi 1 iscsi
svm_linux /vol/vol_linux/lun2 linux_iscsi 2 iscsi
New mapping:
::> lun mapping show
Vserver Path Igroup LUN ID Protocol
---------- ---------------------------------------- ------- ------ --------
svm_linux /vol/vol_linux/lun1 linux_iscsi 2 iscsi
svm_linux /vol/vol_linux/lun2 linux_iscsi 1 iscsi
OS messages/errors:
Oct 12 19:16:08 linux_host kernel: sd 6:0:0:4: Warning! Received an indication that the LUN assignments on this target have changed. The Linux SCSI layer does not automatically remap LUN assignments
...
Oct 12 19:16:17 linux_host kernel: blk_update_request: critical target error, dev sdas, sector 2097151736 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
Oct 12 19:16:17 linux_host kernel: buffer_io_error: 4 callbacks suppressed
Oct 12 19:16:17 linux_host kernel: Buffer I/O error on dev sdas, logical block 262143967, async page read
Application errors/Alert log:
Corrupt block relative dba: 0x00000001 (file 0, block 1)
/u01/app/oracle/admin/diag/db/trace/db.trc:
Bad header found during control file header read
Data in bad block:
type: 6 format: 2 rdba: 0x00811624
last change scn: 0x0000.11124c54 seq: 0x1 flg: 0x06
spare1: 0x0 spare2: 0x0 spare3: 0x0
consistency value in tail: 0x10800601
check value in block header: 0x5cef
computed block checksum: 0x0
Detected a media corrupt controlfile block (block# 1) in '/u05/oradata/db/control02.ctl'