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DocLove
January 5th, 2011, 06:06 PM
Hello,
I have a problem that I hope that someone has a solution to.

I currently have an Ubuntu 10.04 Server with 10 Ė 2TB hard drives (Hot Swappable). I discovered that having a software raid over 16TB is not supported, so I split the drives into 2 sections and have 2 Software Raid arrays to store my movies, audio, pictures, and other software. The total current usage is around 8TB. I only add data about twice a week.

Since backing the files up to DVDís or even BlueRay is laughable, I am going to backup the system to 2TB hard drives probably 5 of them, the problem becomes that I can only hook one backup drive at a time into the system using an external hot swap device. Now I know that I can do this manually by copying the files one at a time to the drive until it is full, switching the drive out and repeating this, but I am hoping for an automated solution, Start backup, plug first drive in, system fills up drive, swap and repeat. Also it would be nice if the system remembered what had already been backed up so when I add files to the system, I only need to attach the last drive and not start the process over.

I hope this makes sense, please ask questions if I havenít been clear.

The Doc.

BrendanC
January 26th, 2011, 12:30 AM
I'm sure this must eb possible becuase it sounds exactly like backing up to a tape without a changer. The tape becomes full and then you change tape and carry on the backup.

Sorry I don't actually know how to do it!

Brendan

CyberCSI
February 3rd, 2011, 07:05 AM
There are many 5 bay eSata enclosures out that that make use of SATA PMP (Port Multiplier) functionality...some (e.g. Venus T5) come with a 2-port SATA controller (Silicon Image) that supports PMP on the host side and are supported generally well under Linux.

I had a setup with Eight 5-bay eSata enclosures...I used 75% of the bays for storage and the remaining 25% for backup "tapes" for my Amanda backup setup. Things worked great once you got the OS to detect a particular drive that you plugged in, however, I found hot-swapping to be unreliable...seemed like if I unmounted and unplugged a drive or "tape" and then put a new one back in the same slot it was a crapshoot if it would get recognized.

It could have easily been some combination of firmware problems either on the PMP controller inside the enclosure or the eSata controller inside the host...however these cards only come with Windows-based fw flash utilities so I never got around to trying to upgrade them.

I ultimately switched to a SAS-based approached for both storage and backup...hot-swap is flawless. 8-port SAS HBAs are about the same price as comprable eSata cards, but you will pay a premium for SAS enclosures...IMO it's completely worth it.

Check out the Storage section on Hard Forum for lots of build examples.