Drobo and DroboShare

D

dave261266

Registered
Guys,

Just want any comments really.

I have had a drobo (1st Gen) for a while now and short of one problem that required a firmware upgrade I have had no real problems with it. I use it to house my media library (TV Shows and Movies) which I play through a couple of Mac Minis to various rooms in the house.

Initially I had this connected to my main machine (iMac) and all was good. The storage was shared out to the mac minis with afp and apart from the iMac being down there were no problems.

One week though I had a hard drive failure on the iMac and it took a couple of days to recover and it became apparent that linking the drobo to the iMac was less than ideal.

So I bought the droboshare and after checking the specs it seemed that it would be great (Gigabit support etc etc)

Since it has been installed the performance has been <please insert rude word!!!>

I raised this with drobo support and had several communications with one of their "back room" engineers.

The upshot was that the most I can expect in terms of throughput from the droboshare is in the region of 6.5MB/sec. Am I alone in thinking that this is appalling.

1Gbit/s network will give 100MB/s
USB connection to the droboshare would top out at 480Mbit/s (48MB/s)

so even given that the droboshare pushes the data out as a samba share I would have expected a reasonable throughput.

When USB connected I get about 30MB/s so I would have thought that the throughput through the droboshare would be roughly the same. But even a 30% drop to 20MB/s would be fine.

Does anyone know why there is such a massive drop in performance ?

Quote from drobo support "6.5MB/s is about right for a droboshare"

when asked if I could talk to an expert on the droboshare so that they could explain to me why it is so slow I got "Yes I do have access to those who know the unit at that level, but unfortunately we are not allowed to disclose how things work"

Now that's class support!!!!

If anyone has any comments or suggestions please let me know.

Dave
 
Hi Dave

I dont have any experience with Drobo, but have had a similar one with Linksys. I bought their NAS200 product which is a NA unit with 2x drive bays, I loaded up 2x 500GB drives in a RAID1 config, got a miserable 3-4MB/s. This is due to the speed of the CPU chip, sure its only rated as 100mbit, so in theory I should get 9-10MB/s. but alas no.

I am currently testing a Synology NAS server, I am getting 30MB/s off the network port (AFP) and am told could get 40MB/s if I upgrade to the next level of product (faster CPU).
While Gigabit is theoretically rated at 100MB/s, you wont get that across a network, even with an Xserve with RAID unit across a Cat 6 network the most I have seen is 55MB/s.

Ed
 
Thanks for that.

I think the thing that I found most frustrating about this whole thing was the lack of openness about the reason for the performance. I was playing devils advocate a bit with the support guy because short of them completely screwing up the samba config on the droboshare it had to be throttled by the cpu in some way. It would have been nice if they just admitted that.

Also, given the cost of the droboshare is fairly high I was surprised that the performance was so poor. Maybe they had a box of 8086 processors lying around and they though "I know what we can use those for ....."

I think I'll ditch the droboshare and go back to either a direct connect or I might try and connect by connecting to the airport extreme which I think will allow me to pick up the volumes over the network via AFP rather than samba. Will still have the issue of the cpu performance on the extreme I guess but at least I won't have the samba translation to do.

Cheers

Dave
 
The guys on the Mac Observers' Mac Geek Gab have experienced this exact issue with the Droboshare. If I recall correctly, the bottleneck of the Droboshare is a somewhat limited embedded CPU, but mostly to do with the Samba sharing being slow. A direct connection is certainly going to deliver more performance.
 
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