[UnixMac]

Well after a couple of days of amazing and Mac-Like trouble free operation, I had to share how happy I am with my new Iomega Ultramax Pro drives I am!

I was looking at far more expensive rack mount type RAID solutions for my video editing and while the performance was a bit better, the price was an order of magnitude higher. I paid about $250 for the LaCie eSATA II card and the drives were just over $500 each.. with 1.5TB per drive (two disks), that's 3TB, plus my built in 1.5TB and I'm good for a LONG time for what I do.

Anyone looking for inexpensive, fast and easy to use (plug-n-play) external storage, this is it!

You can save the $250 for the eSATA card and do a firewire 800 connection btw, but I didn't want to risk bottle necks..

Pics here:

[mduell]

4 drives in RAID0... what are you using for backup?

Also 3TB for $1250 doesn't seem like a terribly good value; you should be able to do it for under a grand.
4x750GB drives is $800, enclosures are $20 a pop ($80), and eSATA cards are $60 for 2 ports... that's $1000.
5x500GB drives is $600, 5x enclosures is $100, and 3 eSATA cards is $180 for a total of $980.

[OreoCookie]

4 drives in a RAID0 is crazy -- especially in a software RAID.
Unfortunately since you bought only external enclosures, you cannot build a RAID5 which combines the benefits of larger per-volume capacity and redundancy.

[UnixMac]

Originally Posted by mduell 

4 drives in RAID0... what are you using for backup?

Also 3TB for $1250 doesn't seem like a terribly good value; you should be able to do it for under a grand.
4x750GB drives is $800, enclosures are $20 a pop ($80), and eSATA cards are $60 for 2 ports... that's $1000.
5x500GB drives is $600, 5x enclosures is $100, and 3 eSATA cards is $180 for a total of $980.

Cheapest I could find a 16MB cache 750GB drive from a reputable dealer was: 750GB Western Digital Caviar SE16 SATA-II 1... (WD7500AAKS) at OWC

And a $60 eSATA card with two outputs is going to be MUCH slower than a 4 port..

read this: LaCie 4 port SATA with Two Big and Biggest S2S

but I'll quote the relevant part..

Though the 4E is priced at $249, keep in mind that lower priced 2 port PCIe SATA host adapters are typically single lane cards and transfer data to multi-bay PM enclosures at half the speeds of the 4 port models.

As for backup... the one drive is primary, the other is back up, it's quite simple..

as for Software RAID, the only software RAID I have is the two internal RAID setup drives in bay 3 and 4, the two enclosures are Intel hardware RAID.. no software RAID at all..

here are the specs from iomega.

Technical Specifications
Product Summary
Iomega's UltraMax Pro Desktop Hard Drive Array eSATA 3Gbits/USB 2.0 1.5TB offers a eSATA interface with the latest SATA 3Gb/s technology for the ultra high data transfer rates: up to 6 times faster than USB 2.0! (eSATA card not included.) It is a high-performance storage solution with two (2) hot swappable SATA II hard drives and hardware RAID features that's ideal for professional-quality video applications or small office environments. Plus, award winning EMC Retrospect Express software is included to protect your important files.

Manufacturer Part Number 33744
Manufacturer Iomega Corporation
Product Name UltraMax Pro Hard Drive Array
Dimensions 6.125" Height x 6.375" Width x 7.875" Depth
Hard Drive 2 x Serial ATA Hot-swappable
Controller 1 x Serial ATA/300 300MBps RAID Controller
Expansion Bays (2 Total/2 Populated)
RAID Levels 0
RAID Levels 1
RAID Levels JBOD
Storage Capacity 1.5TB Installed/1.5TB Maximum
Ports USB 2.0 - USB
Ports 7-pin Serial ATA-300 - eSATA
Brand Name Iomega
Controller Serial ATA/300
Storage Capacity 1.5TB Installed
Estimated Weight 19 lbs

[mduell]

Originally Posted by UnixMac 

Cheapest I could find a 16MB cache 750GB drive from a reputable dealer was: 750GB Western Digital Caviar SE16 SATA-II 1... (WD7500AAKS) at OWC

As usual, Newegg is 15% cheaper ($190) than OWC.

Originally Posted by UnixMac 

And a $60 eSATA card with two outputs is going to be MUCH slower than a 4 port..

read this: LaCie 4 port SATA with Two Big and Biggest S2S

I'd use one port for each enclosure, so there's no performance penalty. If you want hardware RAID, for $250 you could get a hardware SATA RAID card and a couple SATA/eSATA dongles.

[UnixMac]

I am using one port for each, but if I had bought the $60 eSATA card, the chipset on that card is the bottleneck, it's not the same bandwidth as the 4 port version. The hardware RAID is built into the enclosures. I couldn't find a good hardware RAID card for $250, where did you find one?

[OreoCookie]

If you have combined the two hardware RAID0 into one volume, then you use a software RAID. Even if you use two RAID0s, it's still not such a good idea to stick to this setup.

What is the drive setup you use exactly? Is it that you use one 2-drive RAID0 as `primary' and the second RAID0 as backup? Or that you address the drives within one enclosure?

In any case, using a RAID0 as a backup volume doesn't sound like a good idea to me.

[mduell]

Originally Posted by UnixMac 

I am using one port for each, but if I had bought the $60 eSATA card, the chipset on that card is the bottleneck, it's not the same bandwidth as the 4 port version. The hardware RAID is built into the enclosures. I couldn't find a good hardware RAID card for $250, where did you find one?

Each of your enclosures should only have one eSATA port, so you're only using 2 out of 4 eSATA ports on the card, correct? Even the cheap cards give a full 3Gb/s to each port, but even if they didn't it doesn't really matter; your two enclosures combined aren't going to exceed 300MBps sustained.
That LaCie card is for port multiplier enclosures, which don't have hardware RAID, so you need to haul 2x3Gb/s links back to the computer for each cable. But the drives themselves can't push more than ~100MBps, so even if you only had one 3Gb/s link you're fine.
3ware has 2 and 4 port SATA RAID cards in that price range.

[UnixMac]

Originally Posted by OreoCookie 

If you have combined the two hardware RAID0 into one volume, then you use a software RAID. Even if you use two RAID0s, it's still not such a good idea to stick to this setup.

What is the drive setup you use exactly? Is it that you use one 2-drive RAID0 as `primary' and the second RAID0 as backup? Or that you address the drives within one enclosure?

In any case, using a RAID0 as a backup volume doesn't sound like a good idea to me.

both enclosures are independent hardware RAID0's and one backs up the other (not thru MIRROR) but by me manually copying the files over at the end of the day... the statistical chance of not one but both enclosures failing, with the added security of both a home surge protection system and a APC battery backup/surge system are so low that I don't worry about it. If the data was DOD critical, then I'd have some other method, but it's just video and photo data that is important, but not life and death, otherwise I'd have to get an $15000+ RAID system.

[UnixMac]

Originally Posted by mduell 

Each of your enclosures should only have one eSATA port, so you're only using 2 out of 4 eSATA ports on the card, correct? Even the cheap cards give a full 3Gb/s to each port, but even if they didn't it doesn't really matter; your two enclosures combined aren't going to exceed 300MBps sustained.
That LaCie card is for port multiplier enclosures, which don't have hardware RAID, so you need to haul 2x3Gb/s links back to the computer for each cable. But the drives themselves can't push more than ~100MBps, so even if you only had one 3Gb/s link you're fine.
3ware has 2 and 4 port SATA RAID cards in that price range.

I'm just going off the Barefeets data and his words "Maximimum" and the fact that I may add two more enclosures at some point are a possibility.

LaCie's four port SATA II 3Gbits/s PCI-Express Card 4E host adapter is based on the Silicon Image 3124 chipset. This 8 lane card enables Mac Pro and Quad-Core G5 users to make maximum use of the 3Gbit/s bandwidth per data channel. It's a perfect companion to the five bay LaCie S2S enclosure (and other Port Multiplier enclosures). It can also be used with various other SATA enclosures. Of course, it must be pointed out that a Port Multiplier enclosures' actual speed has a practical limit of 235MB/s.

Though the 4E is priced at $249, keep in mind that lower priced 2 port PCIe SATA host adapters are typically single lane cards and transfer data to multi-bay PM enclosures at half the speeds of the 4 port models.

Also this is from here: eSATA PCI Express Card, CalDigit FASTA-4e PCI-e on a very similar 4 port adapter, the comments are self evident.

Not all SATA cards are built the same
"Peak Performance" is not an accurate gauge of performance for video editing and other applications with large file sizes. What matters most is the sustained throughput.

In tests using a Mac Pro and 5 SATA II hard drives striped (RAID 0) in a port multiplier enclosure, the FASTA-4e produced sustained reads of 228MB/s with writes of 211MB/s!

Using a 2GHz G5 Dual-core, with 4 SATA II drives in a RAID 0 direct connect configuration (each drive on a separate port), the CalDigit FASTA-4e produced sustained reads of 295MB/s with writes of 301MB/s!

With the CalDigit FASTA-4e, you have the potential to actually use the greatest speeds and highest sustained throughput available with SATA II 3Gb/s interface drives. Supporting high capacity and high sustained data transfer rates, the FASTA-4e is ideal for setting up video and photo editing "scratch disks", huge photo/MP3/movie libraries and small to medium business file servers.

[OreoCookie]

Originally Posted by UnixMac 

If the data was DOD critical, then I'd have some other method, but it's just video and photo data that is important, but not life and death, otherwise I'd have to get an $15000+ RAID system.

No, you could've gotten a sort of RAID5 for about the same price you've paid. In any case, real hardware RAIDs don't start at the price tag you quote, a Wiebetech RAID starts at $1.6k + drives.

[UnixMac]

Originally Posted by OreoCookie 

No, you could've gotten a sort of RAID5 for about the same price you've paid. In any case, real hardware RAIDs don't start at the price tag you quote, a Wiebetech RAID starts at $1.6k + drives.

besides faster speed (which I really don't need any faster than I have), what advantage would i have gotten in terms or reliability by doing a RAID5, and is it really faster?

This article doesn't give it much flattery: LasCon Storage - Different types of RAID

I have REAL hardware RAID with my solution, and the only disadvantage is that I have to back up my data to the other RAID drive (which frankly I can just run as two separate drives if reliability is an issue). How is RAID 5 any more reliable any? it's still using all the disks, it's not like it's MIRROR, or am I missing something?

the type of RAID I was talking about for $15K was along the lines of this: MacRAID SAN Ready Fibre RAID Storage Solutions or a Apple XRAID with 3+ TB and or even systems with SCSI drives..

[OreoCookie]

Originally Posted by UnixMac 

besides faster speed (which I really don't need any faster than I have), what advantage would i have gotten in terms or reliability by doing a RAID5, and is it really faster?

The point is reliability and nothing else. When one drive fails, you whole backup is gone.

Originally Posted by UnixMac 

How is RAID 5 any more reliable any? it's still using all the disks, it's not like it's MIRROR, or am I missing something?

I'm afraid to say, you are: RAID5 uses one drive to store information in a redundant manner: one drive may fail without losing any data. So a RAID5 protects you against hardware failure and -- unlike mirroring -- you have more usable capacity (if you have N drives of G GB, the usable capacity is (N-1) G where N is typically something like 4,5,6,7).

The article you have linked to only says that it may not be advisable to use a RAID5 for enterprise-class database systems and that there is a reason for that. It doesn't say it's a `bad RAID level'.

Originally Posted by UnixMac 

the type of RAID I was talking about for $15K was along the lines of this: MacRAID SAN Ready Fibre RAID Storage Solutions or a Apple XRAID with 3+ TB and or even systems with SCSI drives..

Why are you comparing your solution to an enterprise-class RAID?
You can have a hardware RAID5 with at least 4 TB usable capacity (5x1 TB drives) for a fraction, just get a WiebeTech RT5e (last time I checked about $1.6k and 5 drives of a capacity of choice).

The Drobo (the other solution) is cheaper and works similarly to a RAID5: you are protected against harddrive failure at the expense of speed (it's about as fast as a network HD/cheap NAS).

[UnixMac]

Ok, I get you... the issue for me I guess is that I am not sure the likely hood of both my primary RAID (1.5TB) and secondary 1.5TB failing seems like a 1:100,000,000 odds.. I back up every day from one to the other, and for both to fail (due to any reason) seems unlikely. In hindsight, had I known I could do a RAID5 for the kind of money you showed, I might have paid a bit more I suppose.

[besson3c]

The other thing about RAID 5 is that you only need 3 disks to do it, and any additional disks in the setup can be used as spares. If a drive fails, the spare drive will automatically be put to use as your data is reconstructed.

If you don't need a real-time backup/mirror, I guess what you have is okay though. I am a big fan of RAID 5 though.

OreoCookie: is software RAID 5 generally inadvisable? I know a lot of people do software RAID 2 (including myself) which works quite well. Does OS X support software RAID 2 and/or 5?

[mduell]

The RAID0+duplication (almost like RAID0+1) is more reliable, IMO, than a RAID5 solution across all 4 disks, and certainly faster for writes (RAID5 write performance is only that of a single disk). With RAID5 you can only lose 1 disk, with the RAID0+duplication setup you can lose one and then you don't care if you also lose it's stripe-buddy. Also without the complexity of the RAID5 math, you're a tad less prone to corruption from the controller.

Software RAID5 is ill-advised, and software RAID2 seems silly.

[besson3c]

Originally Posted by mduell 

The RAID0+duplication (almost like RAID0+1) is more reliable, IMO, than a RAID5 solution across all 4 disks, and certainly faster for writes (RAID5 write performance is only that of a single disk). With RAID5 you can only lose 1 disk, with the RAID0+duplication setup you can lose one and then you don't care if you also lose it's stripe-buddy. Also without the complexity of the RAID5 math, you're a tad less prone to corruption from the controller.

Software RAID5 is ill-advised, and software RAID2 seems silly.

I'm pretty sure you are mistaken about RAID5 only allowing one disk to go bad. With a RAID5 setup, you can have several disks go bad, as long as you have hot spares. What you said is only true if you have no spares.

Sorry, my brain was betraying me... Replace mentions of "RAID 2" with "RAID 1". RAID 1 is RAID 0 + duplication, no? Is this what you meant?

[mduell]

Originally Posted by besson3c 

I'm pretty sure you are mistaken about RAID5 only allowing one disk to go bad. With a RAID5 setup, you can have several disks go bad, as long as you have hot spares. What you said is only true if you have no spares.

Sorry, my brain was betraying me... Replace mentions of "RAID 2" with "RAID 1". RAID 1 is RAID 0 + duplication, no? Is this what you meant?

Hot spares are only useful if you have time to rebuild. Think water damage or heat related events.

RAID1 is mirroring, RAID0 is striping. The with two RAID0s and a manual copy process between them, it's kinda like RAID0+1 but with some other advantages and disadvantages; I called that RAID0+duplication for lack of a better term.

Mentioning RAID2 did seem weird; I'm not aware of any hardware implementation of it anywhere near the prosumer level, but I wasn't going to be surprised if you had found some software implementation for Lunix.

[besson3c]

Originally Posted by mduell 

Hot spares are only useful if you have time to rebuild. Think water damage or heat related events.

RAID1 is mirroring, RAID0 is striping. The with two RAID0s and a manual copy process between them, it's kinda like RAID0+1 but with some other advantages and disadvantages; I called that RAID0+duplication for lack of a better term.

Mentioning RAID2 did seem weird; I'm not aware of any hardware implementation of it anywhere near the prosumer level, but I wasn't going to be surprised if you had found some software implementation for Lunix.

Well, perhaps RAID5 setups + a bunch of spares are best suited for servers, as we have a 6+ TB SAN at work that is built with a RAID5 setup, and we chose RAID5 to maximize space as well as redundancy. When a drive goes bad, on our SAN it's a simple matter of swapping out a drive with a spare when a light comes on.

With a home PC setup, perhaps this is not ideal. For starters, most enclosures are limited as to how many drives will fit into the case, and it seems like a 4 drive setup is best for RAID 5 (3 + spare) if you don't want any downtime when a disk goes bad. Contrast this to just buying two large drives and mirroring this data via RAID 1, and cost wise you would probably still be ahead.

The main advantage I see to RAID 1 or RAID 5 to RAID 0 + manual duplication is that if a drive goes back, you won't lose a single byte of data, in theory. With manual duplication, you are only good up to your last backup time, of course... This is probably not a huge issue with this user, but RAID 1 is pretty nice for a small, simple server.

[mduell]

Right, RAID5 or (0+)1 is better for availability, which is important for enterprise servers.

The OP's enclosures only hold 2 drives each, so for RAID5 he'd have to use software, taking a performance hit (and I don't think OS X even supports it out of the box).

[besson3c]

What software RAID configs will OS X support?

[besson3c]

According to this thread:

Software RAID 5 for OS X - The macosxhints Forums

You can do RAID 0 and 1 with Disk Utility, but software RAID 5 is not yet possible. A poster in this thread makes a good point that ZFS might make this moot, when or if it becomes available.

I was asking because I know that software RAID 5 is possible with Linux....

[OreoCookie]

Originally Posted by besson3c 

OreoCookie: is software RAID 5 generally inadvisable? I know a lot of people do software RAID 2 (including myself) which works quite well. Does OS X support software RAID 2 and/or 5?

OS X simply doesn't have RAID5 capability, so if you want a RAID5 on OS X, it has to be implemented in hardware. I guess that will change with 10.6 and (the presumed) wide adoption of ZFS.

Originally Posted by UnixMac 

I back up every day from one to the other, and for both to fail (due to any reason) seems unlikely. In hindsight, had I known I could do a RAID5 for the kind of money you showed, I might have paid a bit more I suppose.

The chances are not nearly as low for the failure of a RAID0, they are significantly higher than the failure rate of one drive. As long as you don't just clone one RAID0 onto the other, you'll be ok.

[Emrys]

Originally Posted by mduell

Software RAID5 is ill-advised, and software RAID2 seems silly.

I have been using software RAID5 for years, and it works perfectly. I've seen drives fail, and I've had zero data loss. Wondering why you say it isn't advised, when thousands of people use it all day long. If you don't know what you are doing, then maybe I'd agree, but In general software RAID has been stable for years.

Originally Posted by OreoCookie

RAID5 uses one drive to store information in a redundant manner: one drive may fail without losing any data.

Technically, RAID5 uses all disks, and uses a equal portion of each to carry the parity data, but the math is correct. When calculating RAID5 space availability, you use the (N-1) equation.

[mduell]

Originally Posted by Emrys 

I have been using software RAID5 for years, and it works perfectly. I've seen drives fail, and I've had zero data loss. Wondering why you say it isn't advised, when thousands of people use it all day long. If you don't know what you are doing, then maybe I'd agree, but In general software RAID has been stable for years.

Software RAID5 has issues with both performance (banging the CPU for all the parity math, and all that entails) and reliability (in reasonable cost implementations). I'm sure software RAID5 in AIX on POWER is quite reliable, but if you can afford that system, you can probably afford a hardware RAID card.

[Emrys]

I run it on a Linux box at home, and my proc is 98% idle while doing heavy IO. It cost me roughly $1400 for a 1.2TB system that doubles as my web, database, vmware, and whatever else I need a 24/7 box for. This is on an X2 with 2GB of ram. I still don't agree with what your saying here....

Also, AIX doesn't do software RAID5. Not really sure where that came from.