I've installed OMV on a Raspberry Pi to use as a network fileshare/media server between another Pi, a MacBook, a Linux laptop, and a desktop booting a couple of 'Nixes and Wintendo 7.
Attached I have a pair of HGST 1TB drives in a Nexstar GX NST-272S3 dual enclosure I picked up with the intention of using it in RAID1 to serve as a redundant backup of the photos, music, etc. scattered across all my devices as well as share and stream among them and I also will be installing Unison soon to keep everything synced.
Anywho, on the enclosure I can use DIP switches to set it as JBOD, RAID0, or RAID1, but I see in the WEBGUI that OMV is capable of handling the RAID. Is it best to keep it set to JBOD and let OMV handle the RAID, or use the hardware settings to set the RAID and let OMV just see it as a single drive, and why? I just created the filesystem using the hardware RAID1 setting, but it doesn't have anything on it yet and so would be trivial for me to set in JBOD and configure it in OMV.
RAID1 - hardware or software?
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- OMV 4.x
- Mr. Lumbergh
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Why do you want to use Raid1?
If you need high reliability, you better use something else than a Raspi and USB drives, that I why I ask.
Apart from that:
Software. Otherwise if your enclosure fails, your data is lost. Single point of failure. -
Why do you want to use Raid1?
If you need high reliability, you better use something else than a Raspi and USB drives, that I why I ask.
Apart from that:
Software. Otherwise if your enclosure fails, your data is lost. Single point of failure.Paranoia, mostly. I've lost things I considered priceless before because of HDD failures.
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Then do backup instead of raid
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I've lost things I considered priceless before because of HDD failures
RAID1 can't help here. RAID is about data availability and not data protection. You need backup. And USB RAID especially connected to something unreliable as a RPi is only a great way to fool yourself.
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Paranoia, mostly. I've lost things I considered priceless before because of HDD failures.
Raid 1 is not a good idea. Raid 1 over USB is a TERRIBLE idea. Remember, Raid is not a backup! (See the Emby PSA thread in General).
In your situation, you would be far better served leaving the drives independent, and setting up a simple rsync job to sync the drives.
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With rsync you also sync deletes and corruption...
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With rsync you also sync deletes and corruption...
You can... but you can also leave the delete function disabled. I do on one rsync job, and don't on another.. but raid 1 also sync's deletes and corruption.It's a pretty simple set up. I have 2 main rsync jobs, that run between 3 different drives (1 remote).
1. "Drive A" is my working drive. This regularly gets data added to it, removed, used for services, etc. I have an rsync job that sync's this drive to "Drive B", which is another internal drive. The delete function is off on this job, so sometimes I'll have multiple copies of items, etc.. on "Drive B". Usually once a week or so, I go to the webUI, enable the delete function, and run the job manually. This brings the two drives completely in sync. I've thought about setting up another job between "A" and "B" that runs once a week, w/ the delete trigger enabled.. to automatically bring the drives in sync. I've just been doing it manually for so long I've never bothered.
2. "Drive C" is remote, and syncs to "Drive B" every day about 3am. The delete function is enabled on this for this job.
I've been doing the remote setup about a week, but I already really like it. It makes an offsite backup much, much easier. I did the initial sync at home so I wasn't moving a few TB of data over the Internet... then moved it to it's offsite location. I've been watching my logs for signs of a problem but thus far, it appears to be working perfectly.
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You can... but you can also leave the delete function disabled
Or you use rsnapshot
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Or you use rsnapshot
Another good option.
Always more than one way do something it seems. I've never messed with rsnapshot but have been meaning to.
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I've never messed with rsnapshot
Quite easy to set up if you use the rsnapshot plugin.
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Quite easy to set up if you use the rsnapshot plugin.
I'm a serious creature of habit. I'm sure it's easy to set up, and I'm equally sure it works well... I've just been using rsync so long... it's what I always go to whenever looking looking at backing/copying data.
I'm sure I'll try rsnapshot one of these days, and wonder why I stuck with rsync so long..
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Rsnapshot uses rsync.
With your setup, you have no solution against silent errors, i.e. errors you notice after say a month.
With rsnapshot that's solved.
I am using Borg backup with many other benefits. -
RAID1 can't help here. RAID is about data availability and not data protection. You need backup. And USB RAID especially connected to something unreliable as a RPi is only a great way to fool yourself.
Interesting, why? My understanding of RAID1 is that the function is the opposite, a fully-redundant mirroring of drives so that if one fails the other can be used to restore onto the replacement and no data is lost.
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If a file is deleted, it is deleted on both drives.
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a fully-redundant mirroring of drives so that if one fails the other can be used to restore onto the replacement and no data is lost
Nope. mdraid-1 is just the try to implement such redundancy. Hard drives don't die immediately, they usually die slowly and then you get (unnoticed) data corruption. And then it doesn't protect you from all the other sources of data loss and data corruption. A few more thoughts: Home NAS build, FS info
TL;DR: RAID is not backup.
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