HP Ultrium SCSI LTO4 Speed

[JohnnyD]

Hi, I have been using a trial of Backup exec, and was getting 5500/MBmin speed from it, I need to try Retrospect because of restore issues with BE, but am only getting 1500/MBmin from Retrospect V7.6.3.102, Its an Atto ul4d scsi card on XP, what sort of speeds should I be seeing with retrospect?

 

Thanks

 

JD

[Mayoff]

Try this:

 

 

 

Also, here's the registry key again that users can try to adjust to make their SCSI or FC cards go faster:

 

-----------------------------------------------------------------

HKEY_LOCAL_MACHINE

HARDWARE

DEVICEMAP

SCSI

SCSIPORT (Driver --> i.e. Symmpi)

SYSTEM

CURRENTCONTROLSET

SERVICES

(Driver)

PARAMETERS

DEVICE -> MaximumSGList

 

The MaximumSGList value is the one you want to set:

 

(formula: if value 65, 65 - 1 = 64 x 4K = 256K Transfers)

 

65 = 256K transfers

33 = 128K transfers

17 = 64k transfers

 

-----------------------------------------------------------------

 

Where it says "driver", that will be different depending on what kind of HBA it is and often has the brand name somewhat incorporated.

 

Sometimes the MaximumSGList key doesn't exist, the user can add it. Changing this value can have a very tangible affect on performance, I would suggest users who don't like their performance try 256k, and if that doesn't work, 128k (not all cards work with all values).

[JohnnyD]

I don't have exectly that registry path, but I have found HKLM/system/currentcontrolset/services/express2/paramaters/device with that key, it had decimal 255 in there, I changed it to what you said, but it was the same result, I have had 5500 MB/Min from this setup with Backup Exec, so is it a SCSI issue?

[Ramon88]

Is that 5500MB/min vs 1500 MB/min what's in the logs of both programs, or is it something you measured (amount of data dived by time it took in minutes)?

 

Data rates reported by Retrospect are sometimes not very accurate, depending on the verify method used.

 

We can't find Robin's registry entry in our Windows 2008 setup, but we use a SAS hba.

 

My speeds are:

Uncompressed = 1000-1200 MB/min.

Hardware data compression = 1650-1750 MB/min.*

Verify (md5 media verify) = more than 5000MB/min.*

 

*) Data structure dependent, some data just compresses better resulting in higher numbers. So your mileage may vary, depending on your data.

[JohnnyD]

That is actual rate on the Backup exec, it does it in about 4 1/2 hours with verify. Retrospect says it is going to take 8 1/2 hours to complete the backup with a rate of never more than 1500 MB/Min. Are you also using LTO 4, because you re getting simailar speeds to me with retrospect, maybe it just cant do higher speeds like Backup Exec can?

 

JD

[Ramon88]

We're using a HP StorageWorks LTO-4 Ultrium 1760 SAS drive with a HP SC44Ge Host Bus Adapter. Tapes are HP LTO Ultrium 4 1.6 TB RW (model C7974A).

 

We just added Robin's suggestion into the registry, albeit a bit different because we use a SAS hba and Windows 2008 R2.

 

With a 256K setting during the first 5 minutes it now seems to do around 2600-2700MB/min... Compression and Encryption are off and the data are large ZIP files. I need some further testing to be sure if it also works with the regular mixed bunch of files and, most important for us, backup transfers (disk to tape).

[Ramon88]

Okay... No dice... When doing a backup transfer the speed is back to regular.

 

Too bad...

[JohnnyD]

Me Neither

 

I tried all 3 values, and my rate will not go above 1400 MB/Min with retrospect, its less that half waht I get with Backup Exec, Something else is bottlenecking it I think, is anyone getting rates anywhere near the 4000-5000 mark here?

 

JD

[Mayoff]

1) Make sure backup exec drivers are removed before a backup with Retrospect. We load drivers when the program opens, not when the computer starts. The result could be conflicts with Backup exec drivers.

 

2) Is Backup Exec using MB/Min or values per second?

 

3) Make sure you have the latest SCSI Card Drivers and Firmware

 

4) What type of data, big files, little files, etc?

 

5) You could try to turn off MD5 digests in the preferences. This will give you higher speed but reduce your verify options for the media.

[Ramon88]

I do not want to highjack Johnny's topic. But I'm seeing the same performance on a new high end system (Dual quadcore Nehalem with 24GB RAM).

 

We have only installed Windows 2008 Server R2 STD x64 (with HyperV). We did not install any other drivers but Intel network drivers for the four NIC ports (MS's included drivers worked as well, but Intel's own offer a couple of extra tools). The system's RAID controller and HBA SAS controller are running on default MS included drivers. We tried to install HP's HBA drivers, but the installer says the MS included drivers are newer, so we cancelled that.

 

Robin, what speeds are you guys getting? Can we download some ISO file as a backup source, so we can compare notes? We are hearing about BackupExec and BRU achieving superior speeds with LTO-4. This might be a Retrospect problem, or not. But we should be able to at least try to get that clear.