caspur san news andrei maslennikov orsay, april 2001

CASPUR SAN News

Andrei Maslennikov

Orsay, April 2001

A.Maslennikov - Orsay 2001 2

Will be discussed:

• Goals• Fabric• Bridges• Adding a new device to fabric• Our devices• Distributed Tapes• Some plans


Goals

Distributed Tape Drives- Modern tape drives are rather expensive- To get a good ROI drives should be shared at no loss of performance

Stay along with technology that has future- Speeds will grow to 200 MB/sec and to 400 MB/sec - Switches will become interconnectable over WAN with ATM/STM Inteworking Units

Ability to relocate devices et ease- Fibre Channel SAN allows for congestion-free, high-speed connectivity with guaranteed delivery- Since a device is attached to SAN, it may preserve it’s physical location- Devices may be remotely reassigned from one host to another- NB: we only want this for our very central and institutional services


Fabric

Fabric- We use Brocade switches 2400 and 2800 - Currently 2x2400 and 2x2800, 48 ports in total- Brocade Switch:

o supports practically all FC COSes and peripheralso performant: up to 233 MB/seco runs a user-friendly Fabric OS and graphical interfaceo whole SAN can be administered from any switcho allows for zoningo allows for redundant patho duffused to such extent that device vendors consider

Brocade connectivity a must

- Only dim point - OS upgradeso Switch reboot is requiredo Way out: spare ports on other switches and scheduled shutdownso But this is true for any make of switch….


Brocade zone 1 Brocade zone 2

HBAs

Host 1 Host 2Tape

Disk1 Disk2

Host-Based Adapters- We tried Emulex Light Pulse 8000 and Qlogic QLA2200 - Both models are fully supported on Solaris, AIX, Linux, Wxx - We however have discarded QLA2200 at the initial stage, as we observed inteferences between two Solaris hosts connected to the fabric with this HBA and sharing a tape drive:

In this case, a job on host 1 was running a heavy test I/O job on disk 1. And reboot of host 2 resulted in a SCSI timeout error on host 1/disk 1.

- In case of LP8000, this inteference was not seen. So we “jumped the Emulex train” and use them since on all our hosts. We will also be trying QLA2200 again soon, as their driver was long corrected.


Bridges

Bridges- We use 2 Crossroads StorageRouters 4200 to connect SCSI STK 9840 and DLT7000 tape drives to the fabric - 4200 Features:

o supports 2 SCSI buses (diff or single-ended) with up to 15 devices on eacho GBIC slot o automatic configuration

- Problem observed:o We were able to smoothly share DLT over Crossroads box 1 between 6

hostso 9840 on Crossroads box 2 was shareable up to 3 hosts. Adding host 4

meant to jeopardize access to tape on all 4 machines… (tape off-line).

o Crossroads was blaming Emulex and vice versao Solution: two boxes had different firmware. Older firmware worked, newer -

not


New device, step-by-step

- Make sure the fabric login occured

- Find out the device WWNN / WWPN

- Create a device alias (nickname)

- Create/modify zones• normally create one new zone for each HBA (give it an alias!)• populate each zone with one HBA and disk and tape aliases• do not put a disk device into two different zones, unless you know what you are doing• no limitations for tapes - share them!

- Set up the persistent bindings in the HBA driver configuration file

- Create new devices (vary with OS)


Our current devices

Hosts- 5 IBM AIX 4.3.3 ML8 (native and IBM-modified LP8000s)- 6 Solaris 7+/8+ (native LP8000s)

Tapes- 1 STK 9480 - 1 DLT 7000 via Crossroads - 4 LTO on native FC

- All tapes are shared

Disks- 3 Artecon Lynx II arrays (single ctl)- 2 DotHill 4200 arrays (dual AA) - via 2 Gadzoox Bitstrip TW Hubs- 1 DotHill 7100 (dual AA) - 1 IBM 2102 (2 ctl)

- Around 4 TB in total


3584 FC Library

Tape Mounter Tape Dispatcher

Distributed Tapes

9740 STK Library

9740 Mount comands via serial line

3584 mount commands via FC

S A N

hosts

LTOs

Mount request / Free tape via LAN

9840DLT4200 bridge

scsi

(1) Mount request >

(2) Lock wait

< (3) Mount command

< (4) Mount rc

(5) Access Tape

(6) Free Tape >


Some plans

- Bring tapes to Linux DB hosts (backup) • try both LP8000 and QLA2200 on RedHat

- Try small (logical) slices of RAID-5 and RAID-0 • non-shared scratch areas• faster cache areas for AFS on front-end hosts (AIX and Tru64)• system disks?

- GPFS tests on SP3 with 4 DotHill 7200 systems on 4 nodes


Projects for year 2001

Control and Monitoring- agent up and running on all Linux hosts- being ported to other architectures (encryption)- server integration with Syscontrol DB (event logs and configuration)

Syscontrol DB- mysql now, migration to InterBase by the end of 2001- Hosts’ DB and Syslog event collector DB- Hooks for syscontrol applications

Problem management- currently study possible solutions, Razor is one of the options

Console Server- planned for the second half of 2001- currently look at the serial hardware

Security- accent on host-based- host security “index” is being developed to integrate with Syscontrol

caspur san news andrei maslennikov orsay, april 2001

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