Hi there,

All drives were working fine on Adaptec Raid controller. One drive status was suddenly changed from online to Ready state. Please guide me how to make the Ready state drive to online and configure to /dev/sdb using JBOD. Device 0 needs to be configured as /dev/sdb.

Device #0
Device is a Hard drive
State : Ready
Supported : Yes
Transfer Speed : SAS 3.0 Gb/s
Reported Channel,Device(T:L) : 0,0(0:0)
Reported Location : Connector 0, Device 0
Vendor : SEAGATE

Device #1
Device is a Hard drive
State : Online
Supported : Yes
Transfer Speed : SAS 3.0 Gb/s
Reported Channel,Device(T:L) : 0,1(1:0)
Reported Location : Connector 0, Device 1
Vendor : SEAGATE

Device #2
Device is a Hard drive
State : Online
Supported : Yes
Transfer Speed : SAS 3.0 Gb/s
Reported Channel,Device(T:L) : 0,2(2:0)
Reported Location : Connector 0, Device 2
Vendor : SEAGATE

Device #3
Device is a Hard drive
State : Online
Supported : Yes
Transfer Speed : SAS 3.0 Gb/s
Reported Channel,Device(T:L) : 0,3(3:0)
Reported Location : Connector 0, Device 3
Vendor : SEAGATE
Command completed successfully.

So you want to blow away whatever RAID configuration you have on the Adaptec rather than try to determine what is wrong with one of its disks?

I haven't used an adaptec controller in some time but generally speaking for most RAID controllers you can get into the config of the adapter during boot by hitting the keys it prompts for during its firmware load. Before doing anything else at OS level I'd suggest you do that to see what RAID sets and or Virtual drives you have defined.

You may simply need to re-seat the drive in question to have it rebuild or you may need to replace it but doing anything else without knowing what the setup risks damaging what is left. Given you have 4 drives I suspect you're using RAID5 and if so that can survive a single disk failure - however if you lose a second disk in RAID 5 then you'd lose the entire set.

Hi Mensawater, first of all thank you for your suggestions, will do that.

Yes you are right, Raid level 5 configured with 3 disks they are all online. But the READY state drive mounted as a standalone disk on /dev/sdb.

Will it be online when reseating the drive , any possibility? Can we try rebooting the server?

FIRST I recommend backing up your files before doing any other action.

You'd have to reboot to get into the firmware of the controller to see current configuration.

If it was RAID5 with all 4 drives losing the 1 drive doesn't lose the RAID5 set but losing the next drive would so it is important to resolve the missing drive.

If your RAID5 set was built for 4 drives you need to re-establish the 4th drive. Often reseating the drive is all that is needed (assuming it doesn't have physical issues) for it to begin rebuilding the RAID5 set to recreate data and cksums on the 4th drive by reading information from the other 3. If there is a physical issue with the drive such a rebuild might not work and you'd have to replace it to do the rebuild. Note that RAID5 has been known to fail a second disk during the rebuild which is one reason why you want to be sure you have a good backup before doing anything else.

Some RAID controllers do make you initiate the rebuild of 4th drive rather than doing it automatically on re-seat or replacement. You'd have to look at your firmware or find documentation for your controller to determine that.

It is possible that the RAID5 set was originally only 3 drives and the 4th drive was set as a "hot spare". A "hot spare" setup automatically moves data and cksum to the "hot spare" from a drive that failed. Usually I haven't seen that on system controllers for internal drives but rather for external disk arrays. Looking at the firmware would tell you how it is configured.

It is also possible this 4th drive was never in the RAID5 or a "hot spare". If so you can use it as you would any ordinary drive (JBOD as you originally asked). Just remember though that it is a single drive so if it fails any data on it is lost.