[SOLVED] Upgrading HDs how to copy to new RAID

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cp3inc
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[SOLVED] Upgrading HDs how to copy to new RAID

Post by cp3inc » 2013/02/14 15:02:54

I have a CentOS 5.8 system running cPanel. I am trying to upgrade to a RAID 5 with 3 - 2TB Drives.

Currently, I'm running off a RAID 0 with 2 - 1TB Drives. The new RAID is in place, and I have the ability to copy things over. However, I'm not having much success.

The server hosts about 80 domains, 4 or 5 of which are VERY Active. One has about 1000 email accounts, another has about 100 users making changes to databases, and the few others are active selling sites with interaction with paypal and ecommerce shopping carts.

SO, I am not able to take the server down for an extended period of time. It's just not an option.

HOW do I successfully move all the data and keep it current enough to stop the machine and do a final rsync in a timely manner so I don't have to have the server off line for long?

What we've done so far: We have formatted the new RAID 5 with partitions that will match up with the original RAID 0. I have copied each partition to the new RAID, but when we try to rsync, we either get too many errors, or it takes too long to do it, or it just seems to get lost out there. I'm also concerned with leaving deleted data on the copy. ie, if someone deletes an email, I don't want it to suddenly show up again when we move to the new drives. Same for files.

I have been using rsync -avz --del [source] [dest] for the rsync command. But during this process, email started to disappear off the working system and I became concerned that the -del may be deleting from the source rather than from the destination.

Any and all suggestions on how you would do this process would be appreciated.

Carl

gerald_clark
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[SOLVED] Upgrading HDs how to copy to new RAID

Post by gerald_clark » 2013/02/14 15:10:32

CPanel is commercial software.
They make many changes to the system.
You are paying for their support. You should use it.

cp3inc
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Re: Upgrading HDs how to copy to new RAID

Post by cp3inc » 2013/02/14 16:47:00

Gerald,

Thanks for the suggestion.

I have already done that. They suggested I take the server down, install a fresh copy of CentOS and cPanel on the new RAID, then move the accounts over one at a time. Probably a 2 day process.

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Re: Upgrading HDs how to copy to new RAID

Post by TrevorH » 2013/02/14 16:52:39

Schedule downtime on the server and just copy the data over with all services stopped. For 1TB at ~50MB/s you'd need around 5 hours to copy the data over and that assumes that your 1TB is full which it probably isn't.

cp3inc
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Re: Upgrading HDs how to copy to new RAID

Post by cp3inc » 2013/02/14 17:02:19

[quote]
TrevorH wrote:
Schedule downtime on the server and just copy the data over with all services stopped. For 1TB at ~50MB/s you'd need around 5 hours to copy the data over and that assumes that your 1TB is full which it probably isn't.[/quote]

That may be my only option at some point. However, taking down multiple shopping cart sites for 5 hours is not a solution they will approve.

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Re: Upgrading HDs how to copy to new RAID

Post by TrevorH » 2013/02/14 17:15:24

Well I'd start by timing how long it takes to transfer some data from one array to the other and then do the calculation to work out how much data you have and how long it will really take. My 50MB/s was a guesstimate at best and your actual transfer rate might be more or less than that.

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Re: Upgrading HDs how to copy to new RAID

Post by gerald_clark » 2013/02/14 17:27:00

Rsync the data from one array to the other.
You can then stop the services and do a final rsync. It should only take a few minutes.
Test it to see what your actual final rsync time is.

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Re: Upgrading HDs how to copy to new RAID

Post by cp3inc » 2013/02/14 20:33:28

[quote]
gerald_clark wrote:
Rsync the data from one array to the other.
You can then stop the services and do a final rsync. It should only take a few minutes.
Test it to see what your actual final rsync time is.[/quote]

Do you have a suggestion on how to go about this? I've been using rsync -avz . It runs for 8-10 hours and never finishes. It's only about 500GB of data.

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Re: Upgrading HDs how to copy to new RAID

Post by gerald_clark » 2013/02/14 21:07:56

For drive to drive, don't use -z. The compression/uncompression will add to the time.

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Re: Upgrading HDs how to copy to new RAID

Post by cp3inc » 2013/02/14 21:18:36

I'll try that. Just to be sure, is there any chance that the -del will delete items from the SOURCE volume?

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