MSA 20 Performance

[JKnight]

I looking as purchasing the MSA 20 with full shelf (12 drives) to do backup to disk but I concerned about performance. Can anyone give me a idea of real world performance numbers they are getting. Local and LAN based numbers.

Here is the config I am looking at.
MSA 20 Start Kit with 12 drives direct SCSI attached to a new DL380 using Smart Array 6402/128 Controller Card - Windows 2003 - Backup software is Backup Exec v10.

This would be a dedicated backup server to backup 7 Windows Database Servers. Current amount of data is 400GB and not expected to grow beyond 800GB in next 3 years.

Specific questions:
What speed can I expect over current 100Mb LAN to disk and how many streams (jobs) can I run at once.

If network is upgraded to Gigabit what speed and how many streams (jobs) can I expect to run at once.

[Gus Kwong]

Hi,

I have a MSA20 Starter Kit and it is configured with 12x 250MB disks and in RAID ADG.

It has also been setup as backup server. We almost went for the Backup Exec v10, but as a small company we felt EMC-Dantz MultiServer v7 (with value add-on pack) was much more cost effective.

Over the network, we get about 239.7MB/min for writing data. However, locally it can do about 388.1MB/min.

So not very fast at all, but much cheaper than the cost of MSA30. It could have been faster if we choose RAID10.

Gus

ps: if this is helpful, please assign point.

[Stuart Whitby]

By those numbers, your 100Mb card will be enough to saturate it. Depends where the bottleneck is in the comparison system though. I've seen disk backup speeds with multiple streams of over 20MB/sec using high end disks and NetWorker as backup software. I have no idea what kind of connectivity there was between the server and disk though.

Over the network, at night, I'd expect 10MB/sec over 100Mb switched ethernet. I haven't personally sat and watched transfer speeds over Gb networks, but I'd hope for at least 50MB/sec (when I last really showed an interest in them they were fairly new out, and were lucky to hit 400Mb/sec. Quad Fast Ethernet cards were a better option at that time in a cost-per-port comparison). If disks are RAID 5, there's little chance of them writing at 50MB/sec though. Raid 0+1 is better, but halves your disk capacity straight off.

[JKnight]

Gus,

Is this overall speed or per stream (Job) - assuming you are using multiple streams.

If this is overall speed then I'd be very disappointed in performance. It would take about 30 hrs to do a full backup. Sixty hours if data doubles in next 3 years.

[JKnight]

Stuart,

I understand your math here and I was hoping to hear I could get 4 or 5 streams at (10MB/Sec - 600MB/min)over GigE.

Anyone else have a different experience.

[Gus Kwong]

I think it was just single task but I doubt it would be any faster than the speed locally.

If you have 400GB+ data to backup, then yes it would take a very long time. However, bear in mind that if you use Symantec-Veritas Backup Exec 10, you would use "Synthetic" Backup most of the time and it would be unlikely for you to backup 400GB data daily. You would probably use FULL backup once a month.

However, MSA20 is faster than some other brands' USB2 enclosures (so I have been told, but it would make sense).

It is a pity that HP did not introduce 10k drives for the MSA20. If they did, the product will be faster and may even become popular for Entry-level Storage market!

[John Kufrovich]

JKnight,

Lets look at the math,
Theoritical
10Mb/s = 4.4GB/hr, 400GB database would take ~90 hrs backup.

100Mb/s = 45GB/hr, 400GB database ~9 hrs

GigE - 450GB/hr,

I believe BE uses 128k block transfers. Knowing the transfers and using a RAID5 spindles, you should expect ~45MB/s (this number is from behind a 1500 shelf). I wouldn't expect to much difference from SA6402. Using 45MB/s would get you ~160GB/hr.

What kind of backup window do you have?

[JKnight]

160GB/hr Sounds great and more like what I would expect but I am looking for real world numbers. So far I only have one persons experience to go by.

[John Kufrovich]

Backing up a 23G SQL DB takes 8 1/2 minutes.
Again, this is 1500/20.

Even if you have multiple threads you will have to open the network pipe.