RAID1 Storage - advice please!

[superleccy]

Hi

I want to get a large chunk of RAID1 storage for use with my MBP (see sig). I want at least 750GB actual storage (ie, 1.5TB over two disks), or more if my budget will allow.

I like the idea of the LaCie 2big range. But then, should I go for the triple interface (incl FW800) or the Gigabit Ethernet version?

Or, is there another solution I should be aware of? SATA? eSATA?

The drive will basically be a dumping ground for completed projects and watched TV shows. I won't be using the drive for Time Machine.

For Time Machine, I will be using my old Lacie D2 over FW800. If I go for the FW800 2Big therefore, I'll be dasiychaining the devices together.

Thanks in advance for any advice.
Regards
SL

 

[blodwyn]

Hi

I want to get a large chunk of RAID1 storage for use with my MBP (see sig). I want at least 750GB actual storage (ie, 1.5TB over two disks), or more if my budget will allow.

SL

You can build a RAID1 with any two external enclosures, preferably Firewire, so you're not limited to any particular manufacturer. I.e. you could get two empty enclosures and put drives of your choice into them, and then set up the RAID with the Disk Utility. Just for fun I set up a RAID1 mirror on 2x 1GB ThumbDrives, and it worked just fine.

As a footnote, Apple seems to have improved the RAID functions in Leopard. With Tiger, if you unmounted the RAID array and then later remounted it, it would only pick up one side of the mirror. With Leopard it seems (so far at least) that I can dismount and re-mount RAID arrays with no issues.

 

[superleccy]

You can build a RAID1 with any two external enclosures, preferably Firewire, so you're not limited to any particular manufacturer. I.e. you could get two empty enclosures and put drives of your choice into them, and then set up the RAID with the Disk Utility. Just for fun I set up a RAID1 mirror on 2x 1GB ThumbDrives, and it worked just fine.

Ooooh, so you can! (I've just looked at Disk Utility). Thanks for the tip.

I still like the idea of the Lacie 2big though, if only for the tidiness of having the two disks in a single enclosure with a single power supply and a single firewire cable, but still have the ability to daisychain more firewire devices of the back.

Or, is there a super-sexy multi-disk firewire 800 enclosure out there on the market somewhere?

EDIT: Another question? Will software (OS X) RAID give be better or worse performance than hardware RAID provided by (say) the LaCie 2Big?

Cheers
SL

 

[blodwyn]

EDIT: Another question? Will software (OS X) RAID give be better or worse performance than hardware RAID provided by (say) the LaCie 2Big?

The answer is (of course) it depends... Some CPU somewhere has to handle the RAID, so it comes down to whether the external RAID box has the grunt to do a better job than your Mac at handling the throughput. Theoretically a hardware RAID should be a better option than a software RAID, as it steals zero cycles from your Mac, but I'm not sure whether a real world test would show a noticeable difference one way or the other. One thing I would make sure of is that if you go with a hardware RAID, is that you can format it to HFS+ and not be limited to some Linux file format that doesn't support the Mac metadata.

 

[superleccy]

The answer is (of course) it depends...

Indeed... good answer.

I notice that the Lacie 2Big (and other similar solutions and enclosures) are switchable from RAID0 to RAID1 to JBOD. So I can always use OS X Software RAID and JBOD to compare the performance with hardware RAID.

However, Time Machine seems to be creating a rush on these sorts of devices at the moment. I'll have to bide my time!

Many thanks for your help.
SL

 

[tyr2]

Personally if you're going to use external devices with RAID 1 I'd prefer going for the single unit with integrated RAID rather than using the inbuilt RAID in OS X

Mostly because if for some reason you power on one drive of a pair and not the other your RAID will get desynced and you'll have to resync it again, which with OS X means copying the entire data set again, which if you've got 750g on each disk is going to take ages.