Mirroring question

[Sean OB_1]

If I have a 12 disk lun (raid 5) in a FC60 array, and have the entire lun mirrored to a SC30 array, will the system continue to run if I lose a controller (2 disks) in the FC60?

My assumption is that the system will run off the mirror until the controller is back online and then I can resync the mirror.

Can someone verify that this is indeed how it will work?

TIA

[Bill McNAMARA_1 · Accepted solution]

If you lose 2 disks in a raid group the data is not accessible. The mirror will switch after the pv timeout specified byu the pvdisplay timeout property of the lun and the alternate path of the PV (ie the mirror) in the VG. Why not stick with R1/0 on the FC60.

Later,
Bill

[Bill McNAMARA_1]

is the FC60 in full or split bus mode btw.. if the disks haven't failed, ie just the controller, you should be able to access the lun via the remaining controller. In this case the Alternate path will be through the remaining Controller...a third alternate in that case would be the SC30 (FC30??)

Later,
Bill

[Sean OB_1]

Bill,

the client wants the primary to be on a raid set in one building, and mirrored to another array in a different building.

The other building also has the failover service guard server.

My concern is that having a 12 disk lun in the FC60 means that if I lose one drawer I'll lose 2 disks in the lun, which means I lose data.

I'll have the alternate path setup to go through the second channel anyway, but I want to cover my bases in the unlikely event that I lose 2 disks at once in the FC60 lun.

[Bill McNAMARA_1]

You can add as many alternates as you like, and in the case that 2 disks fail, you'll switch to the 2nd alternate.. ie on the other array..
I'd test it first though, there'd more than likely be a timout too large for comfort...

Later,
Bill