MSA 1500 cs - shelves disappeared

[Jeremy C]

MSA 1500 cs with 6 MSA20 shelves. Two of the shelves have effectively vanished, along with all drives. Fortunately, only two drives out of those were in use so there has been no loss of data. Any ideas?

[Víctor Cespón]

Those two MSA20 are connected to the same I/O module?

That's the part that would lead to two disk enclosures dissapearing completly.

[Jeremy C]

To be honest, I wouldn't know. How can I check?

On a related note, since only two drives of those shelves were in use...can I tell the MSA to use different physical drives instead for those logical arrays?

[Jeremy C]

After reading in the forums a bit, I found that it's not uncommon for a failed drive to cause the entire shelf to "vanish". Replacing failed drive and power cycling the MSA brought back the shelves.

Now one drive continues to be unavailable with red light. Tried three different drives and same result with every drive.

[Víctor Cespón]

On the back of the MSA1500 there are I/O modules. There's one SCSI cable from those I/O modules to each MSA20 enclosure.

If you lose access to a MSA20, there are 3 things in the path: I/O Module, SCSI cable and MSA20 controller module.

You cannot remove disks from a RAID, if a drive fails, you must put a disk on that same position.