Best (Cheap) RAID / Storage Solution?

[Vautrin]

Hi,

So I've done it, I've filled up my computer's hard drive with photos.

I'm going to buy a USB RAID, probably around 1TB, so that I'll have plenty of room (at least for a year or two).

Does anyone have any recommendations on good raid / storage solutions?

Thanks,

Dan

 

[Moglex]

For storage solutions generally I'd recommend simple USB external hard drives.

They are now absurdly cheap and you can buy three and use them on a grandfather/father/son system which is generally more resilient than raid, especially if you keep the drives in physically separate locations.

By the time you fill up set of 750GB drives it will probably be time to replace them and a typical drive will have increased in size to give you plenty of extra room.

 

[STICKMAN]

My only comment would be don't go cheap!!! Why not protect your invest ment with a decent raid system. I would be highly upset to set up a system and have it crash on ya due to be a cheaper setup......

 

[Moglex]

Remember the disadvantages of RAID.

1) You need three parallel drives to even approach the resiliance of a G/F/S system.

2) All your data is in physically the same place so theft/fire/mechanical damage are not protected against.

3) A catastrophic software problem (system malfunction/virus/trojan/malware) or user error will simultaneously overwrite/delete all the copies of your data at the same time.

4) If a disk fails you generally need to find one of exactly the same geometry which although it may not be a problem in the long term may cause a delay, especially if a drive fails after a couple of years.

I generally recommend against RAID out of the server room (except for striped arrays deployed for speed) as it seems to give end users a definite sense of false security.

There may be a little more work in a G/F/S system but the increase in protection for irreplacable photographs would seem to be well worth it.

 

[Bifurcator]

Why USB? It's so slow... Considerations:

• Place the big drive internally - fast - cheapest solution.
• a hot-swap bay - fast and portable/interchangeable - can be pricey.
• an external drive with an ethernet connection: 100BaseT, 1000BaseT, Fast - slightly more expensive than USB or firewire.
• a firewire connectable external.
• USB 2.0
• USB 1.x (or 2.0 protocol only)

The transfer speeds relative to the above list look something like:

• > 2000 megabits/sec. Full Duplex
• > 2000 megabits/sec. Full Duplex
• = 1000 megabits/sec. Full Duplex
• ~ 800 megabits/sec. Full Duplex †
• ~ 400 megabits/sec. Half Duplex
• ~ 12 megabits/sec. Half Duplex

† usually 800 these days but can be 400 on el-cheap-o's. some high grade units are 1600 and 3200 too but I think still pricey and not yet mainstream.

Half duplex means you can't read and write at the same time.

USB storage is good if you're sharing the drive between many different types of machines where a USB port is the lowest common denominator. It's very poor as a dedicated or semi-dedicated mass storage interface.

 

[Alex_B]

isn't the idea of a raid to have no interruption in data availability in case a drive fails? Such as for vital server solutions. A raid is not the safe way for long term data storage but for 100% availability all the time IMHO. Hardly needed for personal photography databases.

If you have a raid you still need a reliable backup. See also Moglex's comment.

So why not start with a backup system straight away?

backup -> prevent data loss
raid -> maintain high data accessibility 24/7

people often confuse the two.



And remember, if you do backups on HDDs, use different drives of different vendors of different production batches. identical drives tend to fail around the same time.

 

[Alex_B]

oh, and i prefer external over internal since that way one backup can be located elsewhere (protection against fire, water, theft).

 

[Moglex]

[*] Place the big drive internally - fast - cheapest solution.

And if the machine is damaged/catches fire or gets stolen, bye bye data.

[*] a hot-swap bay - fast and portable/interchangeable - can be pricey.

Why does it need to be hot swap?

Cold swap bays are very cheap and perfectly usable provided you don't want to use the drives like CD's/DVD's.

[*] an external drive with an ethernet connection: 100BaseT, 1000BaseT, Fast - slightly more expensive than USB or firewire.
[*] a firewire connectable external.
[*] USB 2.0
[*] USB 1.x (or 2.0 protocol only)

These are all really compromises.

Whether you need them depends on how you want to use the drive.

If you keep all your active data on the main drive in the machine and just archive/backup on the external you may just as well stick with USB2. It may be a little slower but you're not really going to start off a backup and sit and watch it.

It also has the advantage that you can connect it to just about anything.

I've forgotten exactly but I think the transfer speeds relative to the above list look like:
> 2000 megabits/sec. Full Duplex
> 2000 megabits/sec. Full Duplex
= 1000 megabits/sec. Full Duplex
~ 800 megabits/sec. Full Duplex †
~ 400 megabits/sec. Half Duplex
~ 12 megabits/sec. Half Duplex

These figures are often quoted but are effectively meaningless at least above USB1 as reading and writing of a disk is actually limited by how fast the drive can move data to and from the platter rather than the interconnection speed.

It's very poor as a dedicated or semi-dedicated mass storage interface.

That depends entirely on what you are using it for.

 

[Bifurcator]

isn't the idea of a raid to have no interruption in data availability in case a drive fails? Such as for vital server solutions. A raid is not the safe way for long term data storage but for 100% availability all the time IMHO. Hardly needed for personal photography databases.

Depends on the kind of RAID.

• RAID 0 (striped disks) distributes data across several disks in a way which gives improved speed and full capacity, but all data on all disks will be lost if any one disk fails. Usually increases overall throughout ~75% with each additional drive.
• RAID 1 (mirrored disks) uses two (possibly more) disks which each store the same data, so that data is not lost as long as one disk survives. Total capacity of the array is just the capacity of a single disk. The failure of one drive, in the event of a hardware or software malfunction, does not increase the chance of a failure nor decrease the reliability of the remaining drives (second, third, etc). No speed increase.
• RAID 5 (striped disks with parity) combines three or more disks in a way that protects data against loss of any one disk; the storage capacity of the array is reduced by one disk. The less common RAID 6 can recover from the loss of two disks. Increases speed ~ 70% with each additional storage increasing unit.

Those are the most popular ones anyway. 0+1 and 1+0 are also fairly popular too.

 

[Alex_B]

i was implying raid 5 here. no one i know these days still uses level 0 or 1 anymore.

As for raid, if all drives are the same built, often soon after the first drive fails, one or two others die too. Very bad if you do not like data loss. seen it happening often.

 

[Moglex]

As for raid, if all drives are the same built, often soon after the first drive fails, one or two others die too. Very bad if you do not like data loss. seen it happening often.

This is why I immediately recommended against it for anything other than throughput increase.

It just does not give end users the protection they need for vital data.

As you say above, it's protection element is about high accessibility not medium/long term backup.

 

[Bifurcator]

i was implying raid 5 here. no one i know these days still uses level 0 or 1 anymore.

I guess you don't know many people. No offense. Lone Wolf?

0, 1, 0+1, and 1+0 are still like 100 to 1 more popular than any others. Most (~95%) mother boards with on-board RAID support IDE RAID0 and/or RAID1 only. I guess in an average population of 1000 users it's real close to 50 to 100 who are using 0 or 1 and only between one and three out of that 1000 who have RAID5.

I guess somewhere around 80 or 90 percent of RAID5 users are on high dollar SCSI drives like the Raptor or etc. and not the more reasonable sanely priced IDEs

 

[Tolyk]

Just going to skip the debate on this one, but LaCie makes great external hard drives with integrated RAID abilities, or you can forgo the raid and just use 'em as backup drives. Quite a fair price on the 1TBs, good quality.

 

[Alex_B]

I guess you don't know many people. No offense. Lone Wolf?

Maybe I just know a different kind of people than you do

 

[Bifurcator]

I dunno... I'm in with film and video producers, 3D CG animation artists, matt and comp (composite) artists, and etc. I taught CG animation & comp for 8 years and know hundreds of post production houses and boutiques.

Read the hardware support sites tho and 99% of the questions and recommendations are about 0 and 1 IDE configurations.

The LaCie RAID unit Tolyk mentioned is RAID0 btw.