How to Diagnose Disk I/O Errors on a Virtual LoadMaster
Under some circumstances, disk I/O errors can appear in the system log files of a Virtual LoadMaster. These logs are more typical to a Hardware LoadMaster with an SSD disk that has failed. On a Virtual LoadMaster, it could indicate a potential corruption of the virtual disk assigned to the virtual machine, or possibly an issue relating to a residing physical disk on the host hypervisor.
Here is a sample of the disk I/O logs that may be visible on a Virtual LoadMaster:
Jan 13 09:49:30 lb001 kernel: hda: dma_intr: status=0x51
{ DriveReady SeekComplete Error }
Jan 13 09:49:30 lb001 kernel: hda: dma_intr: error=0x40
{ UncorrectableError }
, LBAsect=3472749701264, sector=206992
Jan 13 09:49:30 lb001 kernel: hda: possibly failed opcode: 0x25
Jan 13 09:49:30 lb001 kernel: end_request: I/O error, dev hda, sector 206992
kernel: attempt to access beyond end of device
Sep 12 08:00:01 VLM-200 kernel: sda2: rw=0, want=7139348872, limit=15326010
Sep 12 10:00:01 VLM-200 kernel: attempt to access beyond end of device
Sep 12 10:00:01 VLM-200 kernel: sda2: rw=0, want=7139348872, limit=15326010