Drobo S Performance Testing

[rajczi]

I have been watching Drobo for several years time as their storage solutions are very compelling but to date have either been way to expensive or way to slow.

They have released a new version of their consumer unit that has an increased capacity of 5 drives and an eSata connector. Prior consumer units had only 4 drives and USB or FW connections. This new version is supposed to handle multiple video streams with far greater performance and stability.

I have contacted Drobo and convinced them to send me a test unit which I will have for a month of performance and stability testing. I would like to see if this unit can remove the complexity of storage management while maintaining acceptable performance for use with Sage. My initial tests will involve running the unit through its paces in direct testing and then moving up to using it as my recordings volume with 4-5 simutaneous tuners and 2-3 comskip and 2-3 playback all running at the same time.

What I really like about the Drobo solution is that I could get all the advantages of BeyondRAID and it's simple/automatic array management and have about 5.4TB usable storage capacity for around $1,300 including the drives. My current system has just over 3tb usable storage with 8 fixed drives and all the headaches associated with that configuration (multiple raid cards, etc).

What I wanted to know from the community is if there are any specific tests you all think I should run. I would also love to hear your thoughts and ideas about using the Drobo S as a primary storage device for a Sage media server.

[traker1001]

IMHO you can't beat FlexRaid, And it is free also. 6 1tb drives in an old computer I had laying around. 5 data raided to 1 parity drive. Then they also are raided to a 1tb network drive that is on a seperate powersupply altogether and UPSed upstairs. all in all the whole setup costed me about $500. I have had to restore more than once and that is quick and works great. To top it all off the Raid program is OS and Hardware InDependant.

[Bandit]

I just got my DROBO S hooked up to my server. I was running a raid 5 array but moved over to the DROBO S. Formatted the server out to Win 7 so I could use one partition instead of having to separate it into 2 TB ones. Haven't tested much yet as I am having issues with 2 of my tuners after the reinstall yesterday. I'll begin testing the performance once I get the tuners working properly.

[GKusnick]

From the Drobo website:

Virtualization completely decouples the physical space available in the array from the space reported to the operating system. This is how BeyondRAID is able to eliminate the need to manually expand/contract the file system as more space becomes available or is removed.

As I recall, one concern that came up in previous Drobo discussions is whether there's any way for Sage to perform accurate free-space calculations on a Drobo volume, since Drobo always reports the theoretical maximum capacity rather than the actual capacity. Can any Drobo users verify whether this is an issue?

[Bandit]

Originally Posted by GKusnick

From the Drobo website:



As I recall, one concern that came up in previous Drobo discussions is whether there's any way for Sage to perform accurate free-space calculations on a Drobo volume, since Drobo always reports the theoretical maximum capacity rather than the actual capacity. Can any Drobo users verify whether this is an issue?

Yes, it would 100% be an issue. I just don't plan on letting mine get close to full, will keep growing the drives as needed.

I run a DROBO S at home and a Drobo Pro(iSCSI) at work, and can say from use, they are very nice.

[stanger89]

So yeah, that brings up a good question, do they still report 16TB space regardless of the disks installed or do they now accurately report free space for the installed drives? Just looking around recently the Pro with iSCSI looks interesting, but IMO that's a deal killer.

[Bandit]

Originally Posted by stanger89

So yeah, that brings up a good question, do they still report 16TB space regardless of the disks installed or do they now accurately report free space for the installed drives? Just looking around recently the Pro with iSCSI looks interesting, but IMO that's a deal killer.

As I stated in earlier post, it still works that way. The only way to see real free space is to open the Drobo Dashboard or mouse over the icon in the system tray. It still reports to the OS as 16 TB.

[evilpenguin]

Would setting Sage to "Use only 1TB" work for that?

[Bandit]

Originally Posted by evilpenguin

Would setting Sage to "Use only 1TB" work for that?

It would if you only used it for live recording. I store many other things on my DROBO as well, so sage isn't aware of all the used space. I keep a good eye on mine so will just upgrade the drives as needed. I threw 3 500GB and two 1 TB drives in to start. Will upgrade the 500's to 2TB drives when I get the cash.

I got my tuner issues resolved so will be testing the usage of the DROBO with Sage soon, so once the OP gets his test unti we'll have 2 people testing

[TwistedMelon]

You could save some money by going with a ReadyNAS Pro Pioneer. It can hold 6 drives.

Some benefits are:

You won't risk losing all your data when replacing a drive (too many Drobo horror stories, though all are second-hand)

You will have much faster speed over a Gigabit LAN connection - but this does require a GigE switch and GigE network port(s) on your computers.

Even more speed if you have two GigE network connections on your computer that can support teaming/bonding. This requires a GigE switch that also supports the feature and the installation of an add-on for the Pioneer model (standard in the non-Pioneer pro model)

Correct volume size reported to the OS.

Automatic and care-free volume expansion with up to 2 drive failure protection.

No problems accessing the device from multiple computers at the same time - the bottle neck is going to be the local drive on your computer.

Larger capacity than 5-drive Drobo - cheaper too depending on where you shop.


What ReadyNAS will not do:

It won't connect directly to your machine. If you go with the non-Pioneer you can use iSCSI and get this functionality back by connecting to a GigE port on your machine. This has to be a secondary port if you're already using the primary obviously.

It won't reduce the volume size as you lose drives. So if you lose one drive, no amount of waiting around will enable you to lose two more. The Drobo (8 drive model) will rebuild and if you have enough free space you can still lose 2 drives simultaneously. In other words, ReadyNAS = 2 disk loss, Drobo = 2 simultaneous drive loss.

Can't hold as much as the 8-disk Drobo obviously.

Can't insert drives without first mounting them in a caddy. The Drobo's caddy-less design is much nicer.

The ReadyNAS is, by comparison, a butt-ugly box compared to the Drobo units. Drobo units appear to have very nice build quality, though since you're not likely to be poking around on a regular basis, that's moot when you throw this thing in a closet or on a rack somewhere.

Also worth looking at is the latest batch of products from QNAP.

[rajczi]

Originally Posted by evilpenguin

Would setting Sage to "Use only 1TB" work for that?

That is how I was planning to configure the system if the Drobo S can meet the performance requirements I am looking for. It is simple enough to know much space is on the array and then how much space is in my long term media storage and set the Sage to only record up to a specific amount. Since sage will simply fill the space, the features of drobo for reporting storage utilization are not nearly as useful as they would be for an archive solution. Knowing when to add storage is a bit more manual with this setup, but the user still doesn't need to know much about raid or drives. If the light is red, replace with a bigger drive.

[rajczi]

Originally Posted by traker1001

IMHO you can't beat FlexRaid, And it is free also. 6 1tb drives in an old computer I had laying around. 5 data raided to 1 parity drive. Then they also are raided to a 1tb network drive that is on a seperate powersupply altogether and UPSed upstairs. all in all the whole setup costed me about $500. I have had to restore more than once and that is quick and works great. To top it all off the Raid program is OS and Hardware InDependant.

I am not sure I follow how this helps. It has abstracted the configuration of the raid from hardware into software. And it still runs on top of some operating system. The would probably be pretty nice once you get it going for managing a video archive, but I can't see using this as the recordings volume where many read and write streams will be hitting it all at the same time (I can record 4xHD & 3xSD, I run up to 3 comskip on live recordings, and I have 3 main clients to 2 secondary clients). I wouldn't think that FlexRAID is designed to handle that from what I am reading.

Please let me know if I have missed something.

[rajczi]

Originally Posted by TwistedMelon

You could save some money by going with a ReadyNAS Pro Pioneer. It can hold 6 drives.

Some benefits are:

You won't risk losing all your data when replacing a drive (too many Drobo horror stories, though all are second-hand)

You will have much faster speed over a Gigabit LAN connection - but this does require a GigE switch and GigE network port(s) on your computers.

Even more speed if you have two GigE network connections on your computer that can support teaming/bonding. This requires a GigE switch that also supports the feature and the installation of an add-on for the Pioneer model (standard in the non-Pioneer pro model)

Correct volume size reported to the OS.

Automatic and care-free volume expansion with up to 2 drive failure protection.

No problems accessing the device from multiple computers at the same time - the bottle neck is going to be the local drive on your computer.

Larger capacity than 5-drive Drobo - cheaper too depending on where you shop.


What ReadyNAS will not do:

It won't connect directly to your machine. If you go with the non-Pioneer you can use iSCSI and get this functionality back by connecting to a GigE port on your machine. This has to be a secondary port if you're already using the primary obviously.

It won't reduce the volume size as you lose drives. So if you lose one drive, no amount of waiting around will enable you to lose two more. The Drobo (8 drive model) will rebuild and if you have enough free space you can still lose 2 drives simultaneously. In other words, ReadyNAS = 2 disk loss, Drobo = 2 simultaneous drive loss.

Can't hold as much as the 8-disk Drobo obviously.

Can't insert drives without first mounting them in a caddy. The Drobo's caddy-less design is much nicer.

The ReadyNAS is, by comparison, a butt-ugly box compared to the Drobo units. Drobo units appear to have very nice build quality, though since you're not likely to be poking around on a regular basis, that's moot when you throw this thing in a closet or on a rack somewhere.

Also worth looking at is the latest batch of products from QNAP.

My initial thoughts are that the cheapest ReadyNAS Pro I saw was about $1100 (I didn't look too hard, and didn't hit ebay) and that was without drives. The Drobo S is $750 without drives. I think I would rather have the extra $350 worth of drives which gives me a 4.5TB head start on the total cost of each solution.

The ReadyNAS has some very nice capabilities. I like the direct access to the storage on the network from other clients, but in my case, I share out the storage volume on my Sage server and would do the same with the Drobo volume so I still have network access from my clients. The ReadyNAS is probably simpler to setup for most people. I run my house in a windows domain and Sage on Server 2003 as a member server but the first person I would put this on doesn't and that will need to be considered.

I would love to have a ReadyNAS to run side by side for performance and management comparison. Maybe I will give Netgear a call and see if they would like to put one in for me to compare.

[rajczi]

Originally Posted by TwistedMelon

What ReadyNAS will not do:

It won't connect directly to your machine. If you go with the non-Pioneer you can use iSCSI and get this functionality back by connecting to a GigE port on your machine. This has to be a secondary port if you're already using the primary obviously.

Since it's a NAS solution, why couldn't you configure a static IP on the ReadyNAS and on a second GigE nic in your machine then direct connect with a crossover? As long as they are both in a different subnet from your main network, I would think this would work fine. It does take away the ability to directly access the ReadyNAS from all the machines on the network, but it would give dedicated access to the ReadyNAS from your Sage box.

Not having worked with the ReadyNAS, please comment if I am missing something...

[rajczi]

Originally Posted by stanger89

So yeah, that brings up a good question, do they still report 16TB space regardless of the disks installed or do they now accurately report free space for the installed drives? Just looking around recently the Pro with iSCSI looks interesting, but IMO that's a deal killer.

The Pro has a lot of nice features, but the price is a deal killer for the home media server market.

[rajczi]

I thought I would give a bit of history for how I got to this:

My father is in the running for the biggest couch potato in history... He currently runs 4 VCR's and a ReplayTV (SD, 80 hour or so). He manually keeps track of what shows are getting recording where and conflict resolution using a paper spreadsheet and the TV Guide. Throw in that he is really not a big fan of computers and the stage is set.

Every time he comes to visit, I have to move much of my video archive off of the main recordings volume to make room for all the stuff he will do in a week or so that he is here. He records a lot of sports which are storage killers (especially golf at 6-8 hours a day for 4 days strait). Last time he was here was during the Tour de France and that was similarly long to golf.

He really likes my system, but I keep putting him off with how complex it is to manage. I think that I can build a stable system around Sage with Extenders on a dedicated machine, but what to do if a drive fails? There is no way I am going to get him to open up the machine and figure which drive failed of a six or eight disk array and replace it remotely. Given the load we all put on disks, those are the weakest link in most of our setups.

The cost and simplicity of the Drobo has been able to fill that gap for a long time, but there was no way I would put the primary storage on a USB volume. I have seen way too many delayed write failures and such for that. Throw in eSATA and now we are talking. I have never seen a single interface error on an eSATA drive, but I have never tested an eSATA raid setup. Given that a decent RAID card costs $300 and the $750 cost of the Drobo S which doesn't need a card is looking more reasonable. Also, the size of a chassis required to do a lot of internal drives is really out of the question. Doing a quality PC with a Drobo S attached is way more in line with what will make him comfortable. If I could do one in a chassis with a display that he can put in place of his replay is even better.

If it works well enough, I will probably replace my setup as well.

Have any of you tried to put your less computer literate friends or family on Sage setups? I have gotten a couple of friends on Sage, but they are local and this one would be very remote...

[GKusnick]

Originally Posted by rajczi

That is how I was planning to configure the system if the Drobo S can meet the performance requirements I am looking for. It is simple enough to know much space is on the array and then how much space is in my long term media storage and set the Sage to only record up to a specific amount. Since sage will simply fill the space, the features of drobo for reporting storage utilization are not nearly as useful as they would be for an archive solution. Knowing when to add storage is a bit more manual with this setup, but the user still doesn't need to know much about raid or drives. If the light is red, replace with a bigger drive.

My concern would be that even if you put a limit on how much space Sage can use, the OS and other apps/services will still mistakenly think there's a lot more free space there and may try to use it for temp files, Windows Update downloads, volume shadow copies, defragmentation buffers, and whatnot.

It might be an interesting experiment to turn on Intelligent Recording and let Sage try to overfill the volume just to see how gracefully (or not) it fails. I'm curious to know what sort of error the Drobo returns if the OS tries to allocate some of that imaginary free space that the Drobo says is there.

[rajczi]

Originally Posted by GKusnick

My concern would be that even if you put a limit on how much space Sage can use, the OS and other apps/services will still mistakenly think there's a lot more free space there and may try to use it for temp files, Windows Update downloads, volume shadow copies, defragmentation buffers, and whatnot.

It might be an interesting experiment to turn on Intelligent Recording and let Sage try to overfill the volume just to see how gracefully (or not) it fails. I'm curious to know what sort of error the Drobo returns if the OS tries to allocate some of that imaginary free space that the Drobo says is there.

I think there is no doubt that Drobo is a bad solution as your system volume. In just about any system I built (including my own) I have a pair of drives mirrored for the system, swap, temp, update, etc. The only thing I would be using my Drobo for would be recordings and long term media storage which is fairly static. In that case, it will be simple to calculate how much space is really available to recordings and then set the limit on sage for how much to record...

[GKusnick]

Originally Posted by rajczi

The only thing I would be using my Drobo for would be recordings and long term media storage which is fairly static.

I understand that's all you intend to use it for. But in the past I have seen large temporary directories with cryptic names appear on my recording drives, presumably put there by the OS for purposes of its own. My assumption is that when downloading giant service packs and such in the background, Windows Update looks for the drive with the most free space rather than just dumping everything onto the boot drive. There may be other apps and system services that use a similar strategy for allocating temporary disk space, and if so, Drobo will confuse them.

[rajczi]

Originally Posted by GKusnick

My concern would be that even if you put a limit on how much space Sage can use, the OS and other apps/services will still mistakenly think there's a lot more free space there and may try to use it for temp files, Windows Update downloads, volume shadow copies, defragmentation buffers, and whatnot.

It might be an interesting experiment to turn on Intelligent Recording and let Sage try to overfill the volume just to see how gracefully (or not) it fails. I'm curious to know what sort of error the Drobo returns if the OS tries to allocate some of that imaginary free space that the Drobo says is there.

Definately a fair point. There are a lot of installers that extract to the drive with the most free space, but I can't imagine those being much more than a couple of gigabytes of temporary usage in the worst cases and with the volume sizes we are talking about, I don't think that would be significant. There may also be some video conversion tools that make some very large temporary files (like PlayOn), but those are typically cleaned up when the demand is finished (and PlayOn will only use the system volume without specific work arounds).

I would think that this should be a fairly workable solution. I will contact my rep at Drobo about getting the unit to report true storage capacity.