Hello forum! I wanted to ask if there was a way to backup my RAID files in case of a catastrophic failure of my device and for some reason my RAID volumes got corrupt. I’ve had a few lock ups of my EX4100 where I’ve had to do a hard restart, so I’m just wanting to prepare for the worst, which could include a corrupt RAID volume. Is there anything such as this being backed up and used to rebuild my 4 6TB drives if the RAID volume becomes corrupt? Is there anything else I can do to be sure I don’t lose 24TB of data?
Thanks for the reply. How do I back this up? And, if I did have a failure and needed to restore, are there any instructions or guidelines for this? Is backing up the RAID volume normally recommended for this type of situation?
As @TonyPh12345 said a RAID volume should be treated no different to any other type of volume. Ultimately RAID is just a way to take the space from a number of disks and amalgamate it into a single “virtual” device to provide extra redundancy and performance. From here you then put a file system on top of the new device and it is identical structurally to a filesystem that resides on just a single physical device.
So back it up the same way you would back up any other Linux based filesystem. Something like rsync to another location would do the job.
Thanks JediNite. I have a deep technical background on alot of things but nothing on the linux side of things, so I’m unfamiliar. I’ll look up rsync and see what I can find. If I were to need to restore this RAID volume in my situation with 4 6TB drives full of my data, is this an ‘easy’ thing to do on one of these NAS devices or how would I go about doing this?
Relatively easy if you have SSH enabled, rsync installed and have verified the contents on the remote end look good. It then just becomes a matter of rsyncing the contents back on once the shares are recreated.
It unfortunate that you have come across the same issue that has been plaguing a number of the EX4100 users in these forums where the unit locks up for no reason and requires a hard reset. The underlying reason is that the unit has a linux kernel panic (similar to a Windows Blue Screen) and locks up as a result. There are some kernel parameters you can pass that trigger an auto reboot when this situation occurs, but does not prevent it initially panicing, but at least you don’t need to yank the power to fix it. If you looks for some of my other posts, you will find details on how to do it.
Thanks for the info - will take a look at some of your posts. My device has been running trouble free for over a year now (almost 2) and this is the first time this has happened, so I’m a little freaked out. Would you recommend I go through this backup of the RAID volume? WD support told me that if this happened and I couldn’t get the device back up, they would ship me a new one and I could just reinsert my drives and all would be good - no data loss. Is this right or should I be cautious of this optimism? I have ALOT of data on these drives that I don’t want to lose, of course.
If you have really 24TB of data, then I conclude that you have it in RAID0, correct? This is the only RAID in which you can have 24TB of data on 4x6TB. If you have a RAID10, then you only have 12TB of data on drives 1 and 3, with drive 2 being a mirror of drive 1 and drive 4 being a mirror of drive 3.
Different RAID options deal with different problems:
RAID0 (4x6TB) gives you high speed but no security on 24TB of user data
RAID1 (2x6TB) gives you security 6TB of user data
RAID 5 (4x6TB) gives you security and speed and reconstruction ability 18TB of user data.
RAID10 (4x6TB) gives you speed and security over 2 disks instead of 1. 12TB of user data.
Which is your setting? If it’s RAID0 then you need more hardware for a back up.
Thanks for the info a question, Beat! I"m on a RAID 5 with the 4X6TB configuration you mentioned, so 18TB of actual data. This is how the NAS came configured, so I chose to leave it this way - hope this was a good decision!!
