Option for offsite backup

[freenas-supero]

Hello

I have re-purposed my old X7DBE+ server as a backup server inside a 1U chassis (supermicro 1U) which is equipped with a BPN-SAS-815TQ backplane and 4 hotswappable drive bays.

The server currently has the following hardware specs:

-Supermicro 1U chassis with 4x hotswppable drive bays
-48GB DDR2-667 ECC RAM
-2x Xeon L5420 2.5GHz (4 cores each)
-The backplane (BPN-SAS-815TQ) is directly attached with SATA cables to the motherboard SATA ports. For now I assume this backplane supports only 2TB drives but if someone can confirm I'd appreciate...Otherwise I will contact Supermicro to ask.

The general idea is to use this older server to perform a backup of my main storage server which runs Freenas 9.10-STABLE. I would perform the backup manually, i.e. start the backup server, dock the hard drives in the hotswappable bays, perform the backup, unmount the drives, shutdown the server and bring the drives off-site.

My current Freenas main storage server uses 8x 2TB drives in a RaidZ3 config (11TB usable). Pool is currently 75% full. Out of the 8TB or so being currently used, there are about 2.6TB I need to backup, the remainder I can retrieve back from other sources should it be necessary.

Some questions come to my mind:

1. Since the backplane supports only 2TB per drive, that would be a raw capacity of 4x2TB=8TB for this server, therefore I wont be able to replicate my entire pool to this server but instead I will backup only specific root folders. Thats why I was leaning towards rsync and a classic linux distro. Should I opt for freenas although I wont do integral pool replication?
2. On the backup server, should I configure all 4 drives to be a single concatenated volume (pool in Freenas language, LVM in Linux) or simply 4 independent disks? Whatever I do I will need to be able to expand (either by adding more drives, as I currently have only 2 drives but will get more in the future) or bigger drives (replacing the 2TB's by 4TB's if the backplane allows...)

I am sure others have done similar stuff, and I'd be glad to hear what you have ended up doing!

 

[MatthewSteinhoff]

My experience is that manual backups don't get done in the vast majority of cases. So, if your data is important, figure out a way to have the secondary server online and replicating at all times. (Automatic backups, too, require attention. But it's a lazier type of attention.)

That Supermicro motherboard uses the ESB2 SATA controller which, if memory serves, only supports drives up to 2TB in size. The backplane shouldn't be the limiting factor. You may be able to drop in a different controller to support disks in excess of 2TB.

1. FreeNAS has really good snapshot and replication tools. Use them. Toward that end, you'll need to carve up your source data into datasets and then choose which datasets need regular replication, which datasets don't need replication and which datasets can be backed up using other methods.

2. If you don't need redundancy on the far end, set the four drives up as a stripe in FreeNAS. That will give you the maximum amount of (non-redundant, likely to die) disk space.

Given the shortage of disk space with 2TB drives on the receiving server, I'm not sure this project is worth the time. If you add a controller that supports larger drives and you toss 4TB or 6TB drives in it, then it may be worth the effort.

Cheers,
Matt

 

[freenas-supero]

That Supermicro motherboard uses the ESB2 SATA controller which, if memory serves, only supports drives up to 2TB in size. The backplane shouldn't be the limiting factor. You may be able to drop in a different controller to support disks in excess of 2TB

Im gonna drop in a M1015, should get me past the 2TB barrier I guess.

1. FreeNAS has really good snapshot and replication tools. Use them. Toward that end, you'll need to carve up your source data into datasets and then choose which datasets need regular replication, which datasets don't need replication and which datasets can be backed up using other methods.

My pool is already carved in datasets. 4 of them to be precise. Perhgaps I should use duplication for only certain datasets and not all? For example, I ripped most of our movie collections, and have tons of content that I dont want to necessarily back up. I could skip that dataset, and backup some other datasets with more important data.

2. If you don't need redundancy on the far end, set the four drives up as a stripe in FreeNAS. That will give you the maximum amount of (non-redundant, likely to die) disk space.

The "likely to die" part of your response worries me a lot. Should I instead go for 4x drives with redundancy even if this is a backup? These will see action only a few times a year for replication of the datasets (perhaps 12 hours each time?) I guess so but being limited to only 4 physical drives limits the capacity of the pool..

Given the shortage of disk space with 2TB drives on the receiving server, I'm not sure this project is worth the time.

I wouldnt say "not worth the time" because of the receiving space on the backup server. If I can dock 4tb's instead of 2tb's, I will, and 4x4 is 16TB with RAIDz2 that would give about 7.3TB which is around 50% redundancy. Not bad but not great.

Anyways food for thoughts, and thanks for your feedback!