Tar command issue with Ultrium LTO-4 1760 on SAS bus

[JACC]

Jimmy, I will check on Monday with our hardware installation people. Unfortunately the server is located in Oregon and I am in North Dakota. I wouldn't mind a trip to the Northwest, but I doubt management would go for it : )

I will post back on Monday.

Thx

[JACC]

Good Morning Jimmy,

I just spoke to the hardware guys and the tape drive is connected to a "Smart Array P212". Sorry for the confusion, originally I had posted based on the purchase order which evidently was done thru the hardware configurator and there were some problems. But we have verifed the tape drive is connected to the P212 via the System Management Homepage.

Details of the controller:

Firmware Version: 2.74
Product Revision: C

If any other info required please let me know.

[Steven E. Protter]

Shalom,

On HP-UX, it is best not to hang a tape drive on the smart card raid interface. Of course with HP-UX, if you do that the drive doesn't show up on ioscan at all.

I would suggest connecting the drive to a standalone scsi card that is not doing hardware raid. There may be a connector on there, but it isn't going to work well.

SEP

[JACC]

Steven,

Thanks for the response.

The controller is not participating in the raid. The tape drive is the only device connected to the stand-alone card.

I think the only card we can get to interface with the tape drives is a smart array card.

JACC

[JACC]

Additional info relating to previous post.


Excerpted from: http://h18000.www1.hp.com/products/quickspecs/10854_na/10854_na.HTML



SAS Controllers
HP SC44Ge SAS Host Bus Adapter
NOTE: Recommended SAS HBA for connecting Ultrium tape drives to G5 ProLiant servers.

HP Smart Array P212
NOTE: Recommended SAS HBA for connecting Ultrium tape drives to G6/G7 ProLiant servers.


Please visit: http://www.hp.com/go/connect for a complete list of Ultrium tape drive compatibility with ProLiant servers and other industry standard servers. 462828-B21
HP Smart Array P400/256MB Controller
405132-B21
HP Smart Array P400/512MB Controller
411064-B21
HP 8 Internal Port SAS HBA with RAID 0/1
NOTE: PCI-X interface
347786-B21

[Jimmy Vance]

Is the P212 Zero memory or 256 cache?

[JACC]

Sorry for the delay. Wheels of bureaucracy turning slowly.


The controller is:

Part Number: 462828-B21-W
Desc: HP Smart Array P212/Zero Memory Controller

[Jimmy Vance]

Here is what I've heard back so far. If I hear anything else I'll pass it on

248 blocks * 512 bytes/block = 126976 bytes.
126976 bytes / (4096 bytes/page) = 31 pages.


The P212 zero memory only supports 31 scatter gather elements per command, and thus has a maximum transfer size of 126976 bytes, as the kernel will not send down any request with a transfer size larger than

(number of scatter gather elements * PAGE_SIZE) == 126976 bytes

Adding a cache board to the P212 might bump up the number of scatter gather elements the controller will report so that a larger block size will work.

[JACC]

Jimmy,

Thanks so much for input. It is greatly appreciated. We are ordering the HP Smart Array P212/256MB Controller and I will post with the results once installed. Hopefully this will cure the ills.

Thanks Again to Everyone for your input. I update points when completed.

JACC

[Cmorrall]

I'm facing a similar problem, although I'm on Windows. I have a setup with two identical libraries connected to (what I thought) was two identical P212 SAS adapters.

When doing performance testing using L&TT I could use 256 block size on one of the libraries but I got an error on the error stating 65536 bytes was the maximum block size supported.

On closer inspection, turns out one of the P212 reports "Array Accelerator Present: True" and a Total Cache size of 144 MB but the other reports "Array Accelerator Present: False".

The suggestion that the cache size will affect what maximum block size you can configure seems a valid one.