P2 offload multiple drives

[DChang]

I use P2CMS to copy over p2 data but on the road I would probably need to transfer the data to two separate external drives, I know P2genie and HDLog let you do this but does P2CMS have this sort of option? If not I would think changing database after the first transfer would do the trick, not really a time saver though.

 

[dd53535353]

How about a mirror raid? I did that with two FW800 drives and it worked well. I am not sure how you'd power them in the field though.

 

[THoff]

The problem with RAID1 is that if you do something stupid to the array like unintentionally deleting files from it, it will happen to both physical drives in the array.

In that sense a JBOD setup has an advantage, especially if you can automate the offloading process using something like P2Genie. You can also give one of the drives to another person to keep in a separate location so if your car gets broken into or stolen while traveling, you don't lose all your footage.

 

[dd53535353]

THoff - Regarding your second point. I am not too familiar with RAID1, so I may have been lucky. I accidentally turned on only one drive to review footage and was able to read all of the files from it.; no problems. The problem was that when I connected the two together again, the raid had to be restored, which took hours. If you were to offload everything to the raid1 and then break up the drives with no intention of using that raid again, would that work. Could something go wrong? Would the raid formatting cause a problem.

I'll have to look into p2genie as it seems like it may be a safer approach.

Not sure it matters, but I used a powerbook G4 and 2 500gb g-drives.

 

[THoff]

Well, that's exactly what RAID1 is supposed to do: protect you from one of the drives in the array being unavailable because it dies or doesn't get turned on. (c8

The downside is that replacing the drive (or turning it on) kicks off a rebuild, and how long that takes depends on how smart the array is and how large the drives are. If you and the OS didn't write to the array when it was in a degraded state, no rebuild will be necessary, but you can't control what the OS does, and it will invariably write something to the array.

I've also had a conversation with someone who had a cheap RAID1-capable external enclosure that got confused and rebuilt the array by copying the contents of the empty replacement for a drive that had failed over the good drive with the data. Needless to say he wasn't a happy camper.

So in a perfect world, yes, you can do what you described -- remove one of the drives in the array and put a blank drive in its place, leaving you with 1 1/2 RAID1 array. It should work, but I wouldn't try it with a $30 enclosure that you just stuffed two hard drives into.

One other issues is what to do with the drive you took out of the array. It's not a drive that you can just drop into a computer and use as-is, it is actually part of a RAID array with a somewhat different structure and some metadata on it. To access the contents, you will normally have to make it part of a RAID array again.

 

[NoahK]

Yup- RAID 1 is totally the workflow I recommend. No reason to manually duplicate onto 2 drives. In fact it's actually counterproductive because you have no way of knowing if you might have only put one thing onto one of the drives. With the RAID you are positive every time.

Noah