Adaptec Raid 5 degraded but won't rebuild with dedicated hot swap drive. Help!


Fully [H]
Apr 16, 2008
Hey guys,

I've got an old Adaptec 8405 card with a raid 5 that lost a drive. I've got a hot swap drive dedicated to the raid but it wont rebuild and I can't figure out why. Mircosemi support who bought out Adaptec keeps telling me to upgrade the drivers which I've tried repeatedly even tried to force them but Windows says the driver isn't compatible.

Tried to force a rebuild but it won't take it.

Wierd thing is the response from Microsemi

Your card is using a PCIe x2, to best performance the card requires a PCIe x8.

As per my previous email, update your software(S)please.

This card is at least 5 years old so would it even see a performance increase moving toa PCIe8?

And I already told the guy I've tried forcing a driver update but it wont take it. Windows is calling it an Adaptec SCSI device.




Oct 9, 2000
I've seen older raid cards that couldn't initiate a rebuild without a reboot. Any chance you can power cycle?

Regardless, I'd be moving anything you need off that volume.

Can't imagine the width of the PCIe bus matters. That reads like tech support's list of stuff to note - e.g., "make sure the connection to the wall outlet is not loose"

Could update the firmware to that Feb release - you may need that to load the driver.


Limp Gawd
Jun 10, 2011
This is a true hardware RAID card and the rebuild should proceed even outside the OS once initiated. See if you can trigger a rebuild from the BIOS configuration screen (Ctrl + A on boot). Delete the spare drive and re-add it as a hot spare for the array.


Aug 17, 2011
the raid card controls the rebuild not the software (hardware raid cards have there own OS and mini PC), first thing i would do is run a backup before messing just in case you manage to eat the array and lose everything

unless you have a backup strongly recommend using raid6 (even with backup main storage is recommended to be raid6)

you should be able to trigger the hotspare to be used (should be automatic really)

not much information here (monstieur option is a good start)