OT - how long to rebuild a raid 1

Yoyodyne wrote on 12/11/2005, 3:55 PM

Just curious if anyone has done this - I'm trying to find out how long it would take to rebuild a raid 1 array after one of the disks has failed. This is just a fact finding mission - I'm just trying to assess the pluses and minuses of a few back up methods - figured I would try here becuase there are lot's of smart folk that frequent this board

Thanks a bunch for any info

Comments

gdstaples wrote on 12/12/2005, 11:37 AM

I just built a RAID 0, 1 and 10 and they all took almost no time at all. Don't do an extensive format if the drives are known to be good and free of bad sectors.

My mistake on the RAID 5 was doing a standard format - HUGE mistake.

On the RAID 5 I was only getting 6MB/sec sustained throughput and on RAID 0 that is now 97MB/sec. You would be better served in a dual RAID 0 configuration or a RAID 10.

Note to self: NEVER consider RAID 5 again :-)

Duncan

gdstaples wrote on 12/12/2005, 12:09 PM

I will remove a drive later today and report back on time to rebuild the RAID 1 array.

Yoyodyne wrote on 12/12/2005, 12:17 PM

Thanks for posting your experience with the Raid 5 - very interesting. I've heard they are very cpu intensive to run & it looks like they take a long time to format...& WOW are they slow -

I'm not to concerned about the creation time or format time for raid 1(although I have had no problems using quick format - after your experience sounds like I'm on the right track :)
I'm wondering how long it takes to be up and running when a drive croaks. From what I understand you have to pull the bad drive (and how do you find the bad drive anyway?) and pop in a new one and then let the riad 1 rebuild itself with the parity information. I've got a buddy that thinks riad 1 is the way to go but he's thinking if a drive croaks you can just keep right on working - I told him that is not the case. You have to do some "digital housekeeping" to get the riad back up and running.

I'm wondering if it might not be easier/quicker to use a drive image utility like True Image as a back up method instead.

Thanks a bunch for posting your experience Duncan - this first person account stuff is a huge resource

gdstaples wrote on 12/13/2005, 1:45 PM

I put 170GB on the RAID 1 and then pulled one of the drives to simulate a failure.

It took just under 2 hours to rebuild the drive.

Both drives are 300GB SATA drives.

FYI - The new drive I put in was unformatted.

Duncan

Yoyodyne wrote on 12/13/2005, 7:26 PM

Thanks for the info.