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drewharty
12-28-2008, 02:30 PM
Hello,

I am a professional photographer and videographer. I work on a dual quad core MacPro with a Lycom 4 port card, one system drive, one internal drive for photo files, two internal drives in raid 0 for video editing, and one 4 bay PM box for archiving P2 master video files. My storage and protection of master files is good; my storage of project files in getting overwhelmed, and I have a few questions about upgrading:

1. With the Lycom 4 port card and a 4 bay PM enclosure, can I have 3 drives in raid 0 and a 3rd drive as backup (I only need to back up active projects.), or is it better to set up a Raid 0 with an even number of drives?

2. Is a raid 0 drive with 4 smaller drives any more or less stable than one with two larger drives? Common sense would suggest to me that fewer drives would be less prone to failure but don't know if there are other factors to consider?

3. Would an Areca 1221x card utilizing raid 6 be a better solution than multiple raid 0 volumes?

4. What software would you recommend for auto back up of data, and will the software back up from unmatched pairs of drives, say from a raid 0 to a single drive?

Thanks, Drew Harty

ricks
12-28-2008, 09:09 PM
Well, let's see. First thing is, doesn't really matter all that much whether it has 2, 3 or 4 drives in a RAID0. A drive failure is the issue and a backup is the solution. Also protects from brain farts: "oops, I erased it" and corruption problems.

I don't really look at number of drives as a huge factor in failure rates. If you test the drives, and if you use quality drives, then failures are relatively infrequent. And whether you have set of 4 x 500 GB drives or a pair of 1TB drives, the failure you plan for is the same. The big difference will be that the set of 4 drives will be twice as fast.

RAID6 does not equal safe. Not ever. RAID6 equals uptime on a server in the event of a drive failure. RAID6 is relatively useless to the small single user database. And like RAID5 it adds NO SECURITY TO YOUR DATA! Its intended purpose is uptime in the event of a drive failure.

I consider a RAID6 or a RAID5 to be just as likely to have a complete failure as a RAID0.

The failure will usually be from a different reason, corruption of the RAID itself. But failures happen. The right way to say that is: shit happens. When things go bad with a fancy hardware RAID, they go really bad. Doesn't matter if you have a $15000 high end unit or a build it yourself $3k system, the complexity is such that if something goes wrong and you don't fix things just the right way, your data can be gone. At that point your backup comes to the rescue.

Backup, Backup, Backup. That is truly the only protection you have.


Not to say an ARECA RAID isn't a nice choice. However, uptime is far less important for a workstation or small shop. RAID6 is pretty much a waste. If you lose a drive, you fix it right now. RAID 6 gives you the ability to ignore it. No small operation or individual needs that capability. Replace the drive and move on to the rebuild.

No RAID of any sort, by itself, replaces the need for a backup. The backup is the important consideration, not the type of RAID. The reason to choose the RAID types is:

Cost
Performance - (includes system overhead issues)
Uptime
Reliability
Maintenance
Expandability
Administrative requirements (how much crap you gotta go through to keep the damn thing running)


My rule is: Keep It Simple.

The main issue is what the backup will be. The RAID type itself is totally secondary to that.

Rick

drewharty
12-29-2008, 09:14 AM
Thanks Rick for the informative reply.

I will go with the "simpler is better" plan and have two 4 bay PM enclosures, but I have more questions.

Since I will be able to swap drives from one enclosure to the other if the power supply fails in one, am I better off putting 2 raid 0 pairs in one box for project data and project data back up and my master files and master back up files in the second box or to split the raid 0 pairs and back up disc between boxes?

Separating project data and master data means the box with master data needs to be only turned on occasionally whereas the project data box will be running for months at a time.

Do you know if a faster Raid 0 (3 or 4 drives instead of 2) will have any appreciable effect on rendering times or the number of realtime effects in FCP, or is that more a function of CPU speed?

Are there any companies making cheap (not the $30 leather ones) storage cases for HDs? I am building up quiet a collection and have no good way to store or label them.

Thanks again, Drew

M.Brane
12-29-2008, 10:37 AM
Are there any companies making cheap (not the $30 leather ones) storage cases for HDs? I am building up quiet a collection and have no good way to store or label them.


I just use the plastic clamshells that the drives come in to store bare drives. Can't get much cheaper than that.

ricks
12-29-2008, 06:49 PM
I don't know what drive setup is best for you. The variables are unlimited. If you want more speed, add more drives. If you want a simpler setup, fit it all into a single box. It will all work well and keep on working.

I did see that Weibetech had some neat little drive boxes, kind of like the old VHS cassette boxes. Right price too.

Rick

drewharty
12-30-2008, 12:28 PM
Hello,

I wasn't specific enough with my question. When a enclosure power supply fails, will it typically destroy data on drives or not effect data on a drive? Or is this unpredictable?

If a power supply failure can damage data, I would put original and back up data in separate boxes.

Thanks,

Drew

ricks
12-30-2008, 12:40 PM
While it is possible a power supply failure could damage data, I have never seen that happen. Typically a failure of a power supply is it quits. That just spins down drives. There may be minor index damage because of an open file but that is usually easily fixed.

I would not worry about a power supply failure causing data loss. Pretty low on my list.

Rick

unclemac
12-30-2008, 06:42 PM
And don't forget about whatever is held in cache will be gone.....typically not worth worrying about as far as I can tell. Usually small files being used repeatedly for reads, but should still be intact on the drive itself.