Performance issue Tru64 LTO3 versus SDLT

[wendling]

hello,
tru64 5.1b
Alphaserver ES47 with an SDLT and LTO3 on 2 separate identical SCSI busses. We use vdump for backup and we have the same performance on LTO as with SDLT.
shouldn't be Lto faster? any idea?

Thank's in advance

configuration of LTO:
CAM Equipment Device Table (EDT) Information:

Inquiry Information:

SCSI Bus ID: 1
SCSI Target ID: 5
SCSI Target LUN: 0
Peripheral Device Type: 0x1 (Sequential Access)
Peripheral Qualifier: 0 (Peripheral Device Connected)
Device Type Modifier: 0
Removable Media: Yes
ANSI Version: 3 (Complies to ANSI X3.xxx-199x, SCSI-3)
ECMA Version: 0
ISO Version: 0
Response Data Format: 2 (SCSI-2)
Normal ACA Support: No
Terminate I/O Process: No
Additional Length: 91
Reserved (byte 5): 0x10
Medium Changer Support: No
Multi-port Device Support: No
Soft Reset Support: No
Command Queuing Support: Yes
Target Transfer Disable: No
Linked Command Support: No
Synchronous Data Transfers: Yes
Support for 16 Bit Transfers: Yes
Support for 32 Bit Transfers: No
Relative Addressing Support: No
Vendor Identification: HP
Product Identification: Ultrium 3-SCSI
Firmware Revision Level: G27D

Configuration of SDLT:
Inquiry Information:

SCSI Bus ID: 6
SCSI Target ID: 4
SCSI Target LUN: 0
Peripheral Device Type: 0x1 (Sequential Access)
Peripheral Qualifier: 0 (Peripheral Device Connected)
Device Type Modifier: 0
Removable Media: Yes
ANSI Version: 2 (Complies to ANSI X3.131-1994, SCSI-2)
ECMA Version: 0
ISO Version: 0
Response Data Format: 2 (SCSI-2)
Terminate I/O Process: No
Additional Length: 53
Soft Reset Support: No
Command Queuing Support: No
Target Transfer Disable: No
Linked Command Support: Yes
Synchronous Data Transfers: Yes
Support for 16 Bit Transfers: Yes
Support for 32 Bit Transfers: No
Relative Addressing Support: No
Vendor Identification: COMPAQ
Product Identification: SDLT320
Firmware Revision Level: 5555

[Rob Leadbeater]

Hi,

An LTO-3 drive should out perform an SDLT320.

I suspect that the SCSI controller may be limiting things. What cards do you have installed in the ES47...?

Cheers,

Rob

[cnb]

Depends...


Which model SCSI adapter are they connected to?

[wendling]

I think the scsi cards are AIC-7892

[Rob Leadbeater · Accepted solution]

It would be useful to know the exact HP part number if possible...

I'm guessing its probably a KZPEA.

http://h18002.www1.hp.com/alphaserver/products/storage/kzpea/index.html

If so, then that will only do 160Mb/s which will be the limiting factor on both your SDLT and LTO drives...

Cheers,

Rob

[wendling]

Thank's Rob,
I'll check at customer site...

[wendling]

the card are NCR53C895
these cards are not very fast no?

[cnb]

That sounds like a KZPCA-AA:

Option Part Number
3X-KZPCA-AA

Spare Part Numbers

3X-KZPCA-AA

146094-001


SCSI Chipset
ncr53c895

Host Bus
32-bit DMA master, PCI

Number of SCSI Channels
Single Channel (with one internal, and one external port)

Transfer Rate
Synchronous:


80 MB/s Ultra2 SCSI

40 MB/s Ultra SCSI

20 MB/s Fast SCSI


Asynchronous :


14MB/s

HTH,

[Rob Leadbeater]

I can't remember for certain, but I'll guess that it's only an Ultra 2 device.

This seems to tally with the initial SCSI data you prompted. That will mean you're limited to 40MB/s max.

Cheers,

Rob

[wendling]

Thank's to all,
i'll se if we can use another SCSI card for the LTO
Regards
Gérard