RAID controller - problem with automatic synchronisation
 

Hello all,

I have a problem with RAID controller. Three days ago my server (server with mirrored 2 drives - disk A and disk B) has been shutted down because some problems with fans. I have took out from this machine disk A and put it to the new server to keep continue of production.

When the broken server was ready to use I have put the disk A to the server and I saw that server start automaticly synchronize two drives. The stupid thing is that it start doing this without my permission.


Is it normal that server start doing disk synchronization automaticly without asking administrator if he need this or not ? If Yes, what for in RAID controller exist option - SYNCHRONIZE DRIVES.
My server is Fujitsu Siemens Primergy RX 100 S5.


Second frustrating problem is ... At the momment when I have put DISK A (disk with newest data) to the server, DISK B (disk with old data) was allready there. Server started automatic synchronization and I think that right now I have wrong data on the drive A.People in support told me that for controller and synchronization process the most important thing is TIME STAMP. So if I would like to replicate the DISKA A to DISK B I must:

- take out all drives
- start the server
- put like a first one drive with newest data - DISK A
- then put DISK B - with old data which will be synchronized with drive DISK A

Is it normal ?


cheers

Dlugasx

1. In general, if a system is set as raid and you add a disk it expects to be in that raid, it will autosync; that's normal.
How you prevent that depends on whether it is SW raid or HW raid.
2. Usually a system would assume that the 'current' working drive attached is the 'newest'/most up to date, so you need to ensure that is the only (raid-ed) drive in at boot. Then, when you add the 2nd drive, it will update the 2nd drive from the first.

Thanks a lot for help. I hope my data is still in good condition. In my opinion automatic RAID synch is stupid thing. Its should be controlled only by administrator, not by controller.

Once again thanks for the answer.