[Graham Jones]

Hi John,

I’ll certainly report back. My understanding is that such a drop can have something to do with what drives you’re using — do you recall what model of drive was installed when you had those problems?

Incidentally, further information from PC Pitstop — on the ARC-8026, you can indeed get greater bandwidth by connecting 2 ports to the RAID controller rather than one. However, the greatest speed gains will be see with SAS/SATA 6.0 drives, and an SAS/SATA 6.0-compatible controller (which the 4300 series are not).

Thanks,
G.

[Graham Jones]

Hi,

one more development… confirmed that both the 4300 series RocketRAID cards and the ARC-8026 SAS expander support hooking both ports of the RocketRAID up to 2 ports on the SAS expander, to double the possible bandwidth. In AMUG’s testing with 16 drive arrays, they found this to increase RAID 5/6 speeds by about 21%.

– G

[Graham Jones]

Hi,

sure, can do, once I get it up and running (probably this weekend).

Just curious specifically what your headaches were with the RR 4322? I’ve had great experience with RocketRAID in the past (except perhaps with port multiplier performance, though that probably has a lot to do with port multipliers in general).

I should clarify that I’m actually using a 4320 with an internal to external adapter until I can get my hands on a 4322. It’s identical to the 4322 except for having 256MB RAM instead of 512MB.

Thanks,
G.

[Graham Jones]

Hi,

I got a confirmation from PC Pitstop — those SFF-8088 to SFF-8088 fanout cables do NOT work with hard drive enclosures.

They also confirmed that their Areca ARC-8026-24 24-bay SAS expanders work with the RocketRAID 4322… so… being an avid do-it-your-selfer I decided I’m going to build an SAS expander 4U rackmount 24-bay enclosure myself. There are plenty of instructions on the web (even videos) of how to do such a thing, most based on the Norco RPC-4224 server case.

I wouldn’t recommend this for everyone — I’ve built over a dozen computers and hard drive towers, so I’m pretty handy with this stuff. Buying it retail would cost about $3000 — I’m building it for less than $1500.

The result will be a 24-bay SAS expander enclosure that only uses one cable, and provides two additional expansion ports. I could’ve gotten slightly better performance by using two 12-port SAS expanders, and hooking up to both ports of my RocketRAID 4322, but I didn’t think it was worth the extra $400.

If you’re interested, I’ll post benchmarks and details about the actual build once I get it put together.

Hope this helps,
Graham.

[Graham Jones]

Hi Bob,

thanks for your quick reply! Yes, you’re right, I’m doing a ton of research — trying to cover all my bases because I know I’m stuck with whatever I buy.

Just to add a little detail on my process, for the sake of other people who might be looking at similar solutions…

The need:

I edit and do colour corrections for major broadcast series. Most of them are 1080i60 ProRes HQ — each show may take up as much as 14-16 terabytes, and I often have two or three shows overlapping each other.

The options:

RocketRAID 2744 ( https://hptmac.com/US/product.php?_index=69 ) is a really interesting card — 4 x SFF-8088 ports, would let me hook up 16 drives, and has pretty decent benchmarks. However, it doesn’t appear to support SAS expanders, so I would be stuck with 16. Also, though it has impressive new switching architecture, it’s not a hardware RAID. After using many different RAID cards, I do notice the CPU hit on non-hardware RAID cards.

RocketRAID 3560 ( https://www.highpoint-tech.com/USA_new/series_rr3500.htm ) is actually supported on Mac, though the hptmac site doesn’t mention it. 800MHz hardwareRAID, 1GB RAM, 1 x SFF-8088 and
6 x SFF-8087 ports. I would need to add internal to external brackets, but these are cheap. I could hook up 24 hard drives without going through the expense of SAS expanders… as much as I’m a power user, more than 24 hard drives on a single system is a little decadent 😉

But… Ned Soltz posted a really interesting blog about his comparison of the 3500 series and 4300 series RocketRAID — https://www.nedreviews.com/2009/03/rocketraid-4322.html — main salient point is that the exact same RAID5 array clocked 50% faster with the 1.2GHz hardware RAID on the 4322.

So… RocketRAID 4322 it is — https://www.highpoint-tech.com/USA_new/series_rr4300.htm — 1.2GHz hardware RAID, 512MB RAM, only two SFF-8088 ports, but the card supports SAS expanders. It also supports on-card battery backups, and I happen to have a spare from another RocketRAID card,

The Habey DS-1280 SAS expander case economically provides 12 drives for each one of the ports, and is confirmed to work well with the RocketRAID 4322. I could just get two Habey cases and be done with it (24 drives total), but there may be an occasion where a client needs to give me footage on an SAS RAID, so if the fanout cables did work it would be REEAALLLY nice. Of course I could always disconnect one of my Habey enclosures while I connect the other one, but that could be inconvenient if I have to span any arrays between the two enclosures.

I have sent an email to Highpoint asking them about the fanout cables. I’ve also sent an email to PC-pitstop.com, which I’ve found to be an amazing source of hard-to-find RAID gear — also, I know they sell both the RR4322 and the fanout cables, so I’m sure they’ve hit this question before.

I’ll report back on what they say. I admit, as you, I’m skeptical… If it’s not compatible, as I expect it won’t be, I’ll just stick with the two Habey enclosures and look for a deal on an SAS expander or switch. I’m not in a rush for the latter, but if I can find a good deal I’ll buy it so I’m prepared for eventualities.

Hope this helps,
Graham.

[Graham Jones]

Hi,

how about this one– very low cost, adds 2 PCIe and 2 PCI:
https://ca.startech.com/product/PEX2PCIE4L-PCI-Express-to-2-PCI-Full-Length-2-PCIe-Single-lane-Expansion-Box

$600 is a steal!

Hope this helps,
Gray.

[Graham Jones]

Hi all,

I have several RAIDs, and one system that can be a little crashy when I shut down, so this happens to me all the time. Solutions:

1. Kill the fsck_hfs process (ignore the warning that may pop up)
2. Run DiskWarrior’s rebuild option — this works better than fsck_hfs and takes far less time than fsck_hfs (a few minutes vs several hours)

I would add:

3. Always put your drives and Mac on a UPS
4. Get a RAID card with a battery if possible — this lets it save data on its last write even after a system crash or power failure. Examples of this would be RocketRAID 4000 series with optional battery.
5. If your system crashes on shutdown, unmount the RAID volumes first before initiating the shutdown.

If this happens a lot, do your best to fix the root problem. If you rebuild a RAID too many times you will run out of directory space. To explain, usually Diskwarrior writes its new directory to free space, and then points to the new directory. That means if something interrupts the process, your original directory is still intact. If you run out of directory space, DiskWarrior will let you know that it must overwrite the existing directory, which means if the process is interrupted you may lose everything.

When that happens, you must copy everything off the RAID and format the volume, then copy everything back. Not the end of the world if you have a lot of space, but certainly an inconvenience.

I think that about covers it?

Hope this helps,
Gray.

[Graham Jones]

Hi,

I’m having the exact same issue… were you ever able to get any answers?

Thanks,
Gray.

[Graham Jones]

Hi,

Thanks for the update; glad to be of service!

Cheers,
G.

[Graham Jones]

Hi,

thanks! Luckily, that fits my need perfectly. Both streams are HDMI, same settings, so whichever card starts first doesn’t matter. Also, I will be doing long takes, so once I start the recording I won’t have to keep switching it on and off.

Thanks again,
Graham.