Diagnostics of Mylex AcceleRAID controller/drives

[Igor Roshchin]

Hello!

I have a machine with FreeBSD (4.3-R) and Mylex RAID controller:
mly0: <Mylex AcceleRAID 352> mem 0xfc000000-0xfc001fff irq 5 at device 4.1 on pci2
mly0: AcceleRAID 352  , 2 channels, firmware 6.00-1-00 (20000426), 32MB RAM

It is configured as RAID 5 with 4 HDDs (hotswappable)

Recently one of the HDDs' indicator turned red. The drive was
taken out, and then put back. Some time later the red light went away.

Here is what I see in the logs:
Mar 31 23:22:52 <kern.crit> host /kernel: mly0: physical device 1:3  command timeout
Mar 31 23:22:52 <kern.crit> host /kernel: mly0: logical device 0 (da0)  critical
Apr  1 16:38:40 <kern.crit> host /kernel: mly0: physical device 1:3  device cannot be accessed
Apr  1 16:40:00 <kern.crit> host /kernel: mly0: physical device 1:3  found
Apr  1 16:40:00 <kern.crit> host /kernel: mly0: physical device 1:3  automatic rebuild started
Apr  1 17:22:58 <kern.crit> host /kernel: mly0: logical device 0 (da0)  automatic rebuild started
Apr  1 17:22:58 <kern.crit> host /kernel: mly0: logical device 0 (da0)  rebuild completed
Apr  1 17:22:58 <kern.crit> host /kernel: mly0: physical device 1:3  rebuild completed
Apr  1 17:22:58 <kern.crit> host /kernel: mly0: physical device 1:3  online
Apr  1 17:22:58 <kern.crit> host /kernel: mly0: logical device 0 (da0)  online


My questions:
0. What has probably happened here ?
1. Does this mean that the HDD is alright, or it needs to be replaced ?
2. Is there any way to test this (HDD and RAID integrity) from within FreeBSD ?
Is there an utility or something else for that ?
3. If I need/decide to replace the HDD - can I do that while the computer
is running ? Would the controller take proper care of the new HDD upon
inserting the new HDD, or I need to do manual configuration/formating ?

Thanks.

Igor

PS. Please keep my address in Cc: