RAID 1 question

sinister_stu · 23 May 2006 at 14:50

How long should it take to rebuild a RAID 1 set comprising two 160GB SATA HDs (containing ~100MB of data)?

Dutch Guy · 23 May 2006 at 15:00

No experience whatsoever but if I assume you mean 100Gb and not 100Mb and I take the maximum speed of the drive at 50MB/s that comes to 34 minutes but I would not be surprised if it takes longer than that.

sinister_stu · 23 May 2006 at 15:11

Dutch Guy said:
No experience whatsoever but if I assume you mean 100Gb and not 100Mb and I take the maximum speed of the drive at 50MB/s that comes to 34 minutes but I would not be surprised if it takes longer than that.

Incorrect assumption...

100MB it is. The reason I asked is because Ii've just set up a RAID 1 set for a backup storage system and wanted to test this. I copied a small amount of data into the array and then removed one of the HDs. I then put the drive back in and started the rebuild, which by my calculations, will take about 2 hours. Seemed a bit long to me.

lucifersam · 23 May 2006 at 15:26

it wont take very long at all infact it would have probably taken less time to get on with it than to create this thread!

sinister_stu · 23 May 2006 at 15:29

lucifersam said:
it wont take very long at all infact it would have probably taken less time to get on with it than to create this thread!

I had started it approximately 1 hour before creating this thread. Currently 79% rebuilt. Never used RAID 1 before so didn't know what to expect, hence the thread. Any ideas why it's going so slow?

(Edit: I'm using an onboard Sil3114 RAID controller)

lucifersam · 23 May 2006 at 15:36

sinister_stu said:
I had started it approximately 1 hour before creating this thread. Currently 79% rebuilt. Never used RAID 1 before so didn't know what to expect, hence the thread. Any ideas why it's going so slow?

(Edit: I'm using an onboard Sil3114 RAID controller)

In that case you are not transfering 100MB of data or you have a faulty disk (check SMART) or a dodgy RAID controller

Dutch Guy · 23 May 2006 at 15:42

100Mb should be done very quickly, basically all that has to happen is that the data has to be copied onto the other drive.

Driver issue, faulty drive or faulty cable perhaps?

sinister_stu · 23 May 2006 at 15:49

Thanks for the replies. I had assumed it would just be copying the data across but wasn't sure as I'd never used RAID 1.

I'll check SMART as soon as the rebuilding is finished and also the cables. I don't think they'll be faulty though as they've worked before... what do you mean by faulty cabling? Anything more than the obvious?

I'll also get the latest drivers, will this mean setting the RAID array up again, or is it all stored in the MBR? I really don't know how RAID works.

Dutch Guy · 23 May 2006 at 15:58

Also check that the drives are running in DMA mode and not PIO mode (Rightclick My Computer, Properties, Hardware, Device Manager, browse to IDE/ATA controllers and click on the relevant one and check)

sinister_stu · 23 May 2006 at 16:00

I checked the DMA settings, that's about all I did know about RAID.

sinister_stu · 23 May 2006 at 16:09

Are there any good free SMART monitors available? I can't seem to find one that is free.

Dutch Guy · 23 May 2006 at 16:15

Sisoft SANDRA and/or Everest might do it.

I run a RAID-0 array on a nForce4 mobo and can't monitor SMART at all in Windows.

So perhaps you can download a utility from the manufacturer to verify the drive is working as it should?

sinister_stu · 23 May 2006 at 16:37

Just updated the Sil3114 drivers and found HDD health, which didn't show the RAID drive(s) before I updated the drivers, but does with the latest ones.

The drives are both ok and the cables are also fine... Now to force a rebuild again...

Edit: Still taking ages to rebuild. Any other ideas?

PapaLaz.uk · 23 May 2006 at 16:47

you may find that whether its 100mb of data or not it has to do the whole drive... it would presume that the replacement drive is in an unformatted (or different) state.