On 01/13/12 6:41 AM, Vahan Yerkanian wrote: > multipath -ll showed everything OK, with both sdb and sdc (the same 24 x 3tb raid6 array) as active and ready. are those controllers aware you're using them for multipathing? RAID cards like that tend to have large caches, and one controllers cache won't see changes written to the other, leading to inconsistent data, unless the controllers have some form of back channel communications between them to coordinate their caches. btw, thats _way_ too many disks in a single disk group, your disk rebuild times with 24 x raid6 will be ouch long. I try and limit my raid groups to 12 drives max, and stripe those. given 24 disks, I'd probably have 2 hot spares, and 2 x 11 raid60, which would provide the space equivalent of 18 disks -- john r pierce N 37, W 122 santa cruz ca mid-left coast