12 February 2004

Question & Answer Sessions

What time do we need to leave here to get to Grizzly Peak without pissing off the staff?

Be there by 10 p.m., please.

Cisco SSID tapdance -- how to deal with annoying SSID time outs?

No good suggestions.

TIFF and JPEG in old format -- what software to use?

Two different ways to wrap JPEG inside a TIFF and libtiff doesn't handle it. (It claims to support the old method, but the support isn't there.)

No idea. Might be a new group dealing with it now.

Check for a TIFF to TIFF converter somewhere?

1024 x 768 with amazing ghosting -- should I get a new monitor?

Need new monitor.

Aliases + SPF -- what about it?

Needs more discussion -- toss it around on the list, perhaps.

Strange e-mail -- what's with all that?

Trying to fake out (and poison) the bayesian filters.

hping and other tools to forge IP stuff -- what's available?

Mike wants to pretend he's 10.* to see if he's got a rogue running around. hping should do the trick.

got jobs?

Troy wants one; doesn't need a housemate, though.

Post at michiganworks.org.

Less spam this month?

Interesting. The drop seems hit and miss. Most people haven't noticed a significant drop. Probably an upstream ISP blocking the really bad IP blocks.

How do you figure out (in 20 minutes or less) how to set effective mail filtering?

White list.

Henry Ford Health Systems -- any work experience?

Nothing currently known. (Best of luck.)

Should a filesystem care about UIDMAX?

Well ... somtimes. UID's greater than 2^31 passed over NFS get interesting. Things get more interesting when you backup a filesystem and restore.

I.e., restore as root, then chown fails ... and you've got a potential setuid exploit.

So ... no. But all too often, it does.

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Presentation

Yariv Glazer presents:

     iSCSI Overview
     Current State of the Technology

Started with scsi and tried to emulate the fiberchannel network.  

Corparate Introduction

  YaGUSA Technology, a part of the YaGUSA Group, is a high level system
  intetrator and consultant specializing in enhanced services such as
  unified messaging, smart messaging, etc.

iSCSI Protocol

  iSCSI sits on top of tcp/ip (not udp due to reliability issues)

  SCSI layer talks to both the SCSI device controller and iSCSI
  via the NIC

  Encapsulation:
     IP network
     +-> TCP/IP
         +-> iSCSI
             +-> SCSI Commands/Data

  - sessions between initiator and target
  - each session contains one or more connectiosn
  - each connection goes through a login phase

  + iSCSI help make offsite (or just off-host) backups practical

  - tcp can saturate 1 ghz of cpu per 1 gpbs line speed
  - networking speeds outpacing server and storeage speeds
  - tcp/ip acceleration no longer an option -- IT IS ESSENTIAL!

  iSCSI HGA - features to look for

    - complete offload
    - OS support: NT/2000/Win2003 & Linux
    - supports both network interfaces (RJ45 and LC)

iSCSI host connectivity

high availability, security and comparisons

  iSCSI over tcp/ip
  session maintained as connections migrate
  IP take over and take back using heartbeat packets


Symmetrical and Asymmetrical Mirroring

  Data replication network based -- switch with volume management

  iSCSI "switches" handle the mirroring (they're much more than a
  switch; the name was chosen so as to not confuse Suits)

  Multi-platform mgt
    - host independent
    - simplify management

  Performance
    - does not consume host CPU
    - no bottleneck
    - load balancing between boxes
    - no latency addion over iscsi

  scalability
    - no limitation on the number of hosts
    - amount of storage is scaled by the number of switch elements

  high availability
    - no single point of failure

  Journaling - important for large systems.

  snapshots can be problematic if data is not flushed to disk
  (e.g., Oracle) -- very nice nonetheless, due to the speed

This is neat stuff -- keep an eye open for it.

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Rumor & Innuendo (No names, please)

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