Btrfs with Synology DSM 6 - Your Advice Please
Hi all,
How are you keeping? It has been a while since my last post here re. my Synology setup, largely thanks to all the members here who helped me in that decision :mrgreen:
http://forums.hexus.net/pc-hardware-...nas-but-3.html
Migrating to Btrfs with DSM 6
To give you an overview, I'm currently running a 1515+ as my primary NAS and an 1815+ as the backup.
Both units have 5x 4TB WD Red Pros configured as RAID 5 (ugh, my mistake!).
Since December, the 1815 is backed up to on a 24 hr cycle via rsync (which is now shown in Hyper Backup) and Shared folder syncing.
So what I want to do is this:
1. Perform a final backup, kick off a full re-sync of shared folders, rsync my LUN backups (iSCSI) etc.
2. Wipe the existing RAID volume
3. Create a new RAID6 volume as Btrfs.
That's the easy part. Now, how and what's the easiest way to copy data over from the 1815 to the newly setup primary 1515? I'll of course (most likely) need to re-create the shared folders in the new volume
However, I do not want to do this as wiping my backup array leaves me dangling till things are recovered, therefore:
Adding a second 1815+ with 4x 6TB Red Pros
This works out to ~ US$2,250/- which is OK in terms of out-lay. I would then prep this as RAID6 + Btrfs and migrate my data across first.
Bottom line - What are your thoughts on Btrfs with Synology
Let me know. Also, would you recommend SHR2 or Raid 6? My reach has lead to most saying that SHR2 has a larger overhead, but it does offer the option to mix-match volume sizes.
I'm leaning towards Raid 6 for now though.
Thanks again for all your advice, Cheers!!
Re: Btrfs with Synology DSM 6 - Your Advice Please
While I will steer clear of the BTRFS query, having not used it previously......I would certainly look at adding another drive and then going RAID6. 5 Disks for RAID 5 is good, 1 for parity, leaving a nice even split of data over the remaining 4 drives. Going RAID 6 with 6 drives (2 for parity) gives you that same split.
Re: Btrfs with Synology DSM 6 - Your Advice Please
Quote:
Originally Posted by
shaithis
While I will steer clear of the BTRFS query, having not used it previously......I would certainly look at adding another drive and then going RAID6. 5 Disks for RAID 5 is good, 1 for parity, leaving a nice even split of data over the remaining 4 drives. Going RAID 6 with 6 drives (2 for parity) gives you that same split.
Well, I want to switch over to RAID6 to avoid the URE error that seems to plague RAID 5 arrays over 12TB, see link (https://news.ycombinator.com/item?id=8306499)
Quote:
10^14 is bits. When you divide 10^14 by 8 you get 12.5 trillion bytes, or 12.5 TB.
If you have 4x 4TB drives in RAID5, and one fails, then in order to rebuild with a replacement drive, you have to read all data from all surviving drives (3 x 4TB = 12TB).
Here is an example from a manufacturer:
http://www.seagate.com/files/www-con...ct-content/con...
They call it "Non-recoverable Read Errors per Bits Read" and then list "1 sector per 10^15". So for every 10^15 bits read they expect 1 sector to be unreadable.
The Red Pros are rated at <10 per 10^15, which is 10^14. Cute that they 'scale' their docs to make it sound like it's an order more than 10^14 LOL
