Planning for Large Configuration of Netra™ t1 Server
Contents
1. amps requirement is 16 x 0 39 6 24 amps which is less than 24 amps However using the admittedly conservative 1 5 amp rating for 100VAC the calculation is 16 x 1 5 24 amps which is the maximum rating for the sequencer Note that this does not include the current required for the rack s fan unit if installed Another issue to consider is related to the potential in rush current When a server is initially powered on a transient spike occurs in the level of current as the capacitors are charged within the power supply This high current level decays very quickly generally in less than 200 milliseconds The exact amount of current varies depending on when the power is applied with respect to the AC power cycle The Planning for Large Configurations of Netra t1 Servers January 2001 in rush current is maximized if power is applied at the point where the positive or negative voltage is at it s greatest value The in rush current is minimized if power is applied at the zero crossing point when the voltage is momentarily at zero AC power generally goes through this cycle at 50 to 60 Hz The potential maximum amount of in rush current for a Netra tl server depends upon how long the unit has been turned off A cold start occurs when the unit has been powered off for about one minute or longer A warm start occurs when the unit has been powered off for less than about one minute for example if the power goes off and comes back on wi2. as the ability to remotely power a server on and off The LOM functionality is accessed over an RS 232 serial port that is available via an RJ45 connector on the back of the unit Altogether there are four RJ45 connectors on the back of the unit two of which are 10 100 Mbps Ethernet ports with standard wiring pinouts and two of which are RS 232 serial ports The LOM features are accessed via the Serial A port The remote console can be accessed via either the Serial A port or the Serial B port If you are using a remote console and LOM features you should connect the remote console to Serial B port since its function is totally independent of the LOM facility To manage and monitor a Netra t1 system you must use at least one of the serial ports You can connect either or both serial ports to any of the following devices a A dumb terminal or a Sun workstation For either or these purposes you can use the standard RJ45 patch cable supplied with the Netra t1 server but you need to insert one end into the DB25 adapter which is also supplied with the Netra t1 system a A modem For this connection you can use the standard RJ45 patch cable supplied with the Netra t1 server but you must insert one end into the DB25 adapter which is also supplied with the system Do not connect a modem to the Serial A LOM port use the Serial B port The DTR signal that is asserted on the Serial A LOM port changes to DCD when the system is booted or when
3. level agreements call for very high availability it is recommended that you attach only six Netra t1 units to each power sequencer without using splitter cables Three units should be attached to the Switched1 group and three units should be attached to the Switched2 group In this situation if three Netra t1 units are powered on simultaneously the maximum in rush current should never exceed 300 amps Powering Densely Populated Racks 13 Electrical Requirements for Netra t1 Server The following tables show the electrical requirements for the Netra t1 model 100 server and Netra t1 model 105 server This information is included here for your convenience since some of the values shown have not yet been published in the Netra documentation TABLE 6 Netra t1 model 105 server Maximum Design Values at Rated Nominal Voltage Voltage V 100 VAC Current A 10A Power W 100 W In rush current A Less than 100A decaying to normal in 200 msec at 264 VAC warm start Rated current of 15 A system Rated voltage of 100 240 VAC Nominal system TABLE 7 Netra t1 model 105 server Measured Values Configuration 1 440 MHz CPU 1 GByte memory 4 memory modules 1 CD ROM 2 1 18 GByte 10K rpm disk drive 1 PCI Card QFE Running Sun VTS Voltage V 100 VAC Current A 0 85A Power W 84 5 W In rush current A 56 A for less than 5 msec decaying to 1A in less than 20 msec at 264 VAC cold start 14 Planning for Large Configuratio
4. over several days Generally this upgrade strategy will work with server farms that use load balancing mechanisms a common approach in service provider front end applications Note that Netra servers are qualified to run the Solaris 2 6 7 and 8 Operating Environments 2 Planning for Large Configurations of Netra t1 Servers January 2001 a Is it possible to redirect user traffic to a secondary site while you upgrade the primary site If the secondary site offers reduced capacity you must determine if your service levels allow for degraded performance during the upgrade period Once the upgrade is complete it should be a straightforward matter to redirect user traffic back to the primary site m If neither of the above approaches will work can you shut down 50 of the servers at your primary site and upgrade them and then shut down the other 50 of the servers and upgrade them all during a single offpeak period Because of change management requirements there may come a point at which it makes more sense to move up the vertical scaling curve For example you might deploy your application across two processor Netra t 1125 servers or four processor Netra t 1405 servers instead of single processor Netra t1 servers However your application must be able to scale vertically as well as horizontally for this approach to work Setting Up the LOM Serial Connector The Netra t1 servers support Lights Out Management LOM features such
5. section applies to both models but the focus here is on the AC powered model since that model requires special power considerations Calculating Power Requirements You should determine your overall power requirements and verify that your site can support those power requirements The power requirements for the individual components within a Netra t1 server are shown in TABLE 3 TABLE 3 Estimated Power Consumption for Netra t1 Components Component Estimated Power Consumption at 100 PSU efficiency CPU 360 MHz 34 3 W CPU 440MHz 36 3 W Memory per DIMM 0 21 W per 64 MBytes 9 GByte 7200 rpm 11 0 W Disk Drive 18 GByte 10000 rpm 13 8 W Disk Drive CD ROM 3 2 W PCI Card Variable 25 W maximum TABLE 3 assumes the power supply unit PSU is operating at 100 efficiency You should allow for 65 PSU efficiency So to determine a Netra t1 server s total power requirements add together the figures from the table for each installed component and divide the result by 0 65 For example assume a Netra t1 unit contains a 440 MHz CPU a 512 Mbyte RAM a Two 9 Gbyte disk drives 10 Planning for Large Configurations of Netra t1 Servers January 2001 You would calculate the unit s power requirements as follows 36 3 0 21 x 8 11 0 x 2 W 65 92 28 W To calculate the total power requirements for all servers installed in a rack simply add up the power requirement figures for the individual servers Appl
6. Planning for Large Configuration of Netra t1 Server By Stan Stringfellow Special to Sun BluePrints OnLine Sun BluePrints OnLine January 2001 microsystems ENTERPRISE ENGINEERING http www sun com blueprints Sun Microsystems Inc 901 San Antonio Road Palo Alto CA 94303 USA 650 960 1300 fax 650 969 9131 Part No 806 6640 10 Revision 01 01 10 01 Edition January 2001 Copyright 2001 Sun Microsystems Inc 901 San Antonio Road Palo Alto California 94303 U S A All rights reserved This product or document is protected by copyright and distributed under licenses restricting its use copying distribution and decompilation No part of this product or document may be reproduced in any form by any means without prior written authorization of Sun and its licensors ifany Third party software including font technology is copyrighted and licensed from Sun suppliers Parts of the product may be derived from Berkeley BSD systems licensed from the University of California UNIX is a registered trademark in the U S and other countries exclusively licensed through X Open Company Ltd Sun Sun Microsystems the Sun logo Sun BluePrints Netra Sun Professional Services Sun Enterprise Starfire and Solaris are trademarks or registered trademarks of Sun Microsystems Inc in the U S and other countries The OPEN LOOK and Sun Graphical User Interface was developed by Sun Microsystems Inc for its u
7. TY then STSCTL SMONALARM on else STSCTL SMONALARM of f fi MAIN Ignore common signals HUP INTR QUIT trap I trap 2 trap 3 What s the current state of play This sets shell variables fanl etc to their states ok or faulty if they are configured Planning for Large Configurations of Netra t1 Servers January 2001 eval STSSTATE if 0 then Can t go on exit fi Set the initial alarm state doalarm Now enter the loop waiting for a change and setting the alarm accordingly Have to handle any combination of supported monitor bits hence the long winded parameter substitutions below If this system monitor doesn t report it it isn t configured while eval STSSTATE wait fanl fanl S fanl S fan2 fan2 Sfan2 fan3 fan3 fan3 S fan4 fan4 Sfan4 S alarm3 alarm3 Salarm3 supplya supplya Ssupplya supplyb supplyb Ssupplyb S watchdog watchdog Swatchdog do doalarm done Manageability of Server Farms 9 Powering Densely Populated Racks There are two Netra t1 models the AC powered Netra t1 model 105 server and the DC powered Netra t1 model 100 server The power supply unit is the only difference between the two models DC power is typically used in Telco environments and AC power is used in other service provider environments Much of the information in this
8. as fan failures and alarm state changes are stored in an event log of ten events The oldest fatal event is stored separately as the most likely cause of subsequent failures To avoid filling the event log with repeated failures from a given source only the first failure from any given source is stored After you clear the fault you can re enable monitoring of the failed device by restoring standby power to the system if the system was powered off to repair the fault or by issuing a check command at the LOMlite prompt The LOMlite command line interface which you can display on the console by entering a control sequence is beyond the scope of this article Re enabling device monitoring also clears the error indication on the fault LED All device state changes are reported via the interface to the Solaris Operating Environment which provides additional capacity for storing such events Netra t Alarms The Netra servers support four separate alarms One is the system alarm which indicates whether or not the operating system is running This alarm is reset periodically by a UNIX process called the watchdog If the watchdog fails to fire it is an indication that the operating system has stopped running The LOM hardware notices failure and if it is configured appropriately it reboots the Netra t1 server The other three alarms are user configurable and are not tied into system resets These alarms are typically used by applications For e
9. be treated as a field replaceable unit FRU Note that the Netra t1 server is factory shipped with the Solaris Operating Environment and the Lights Out Management LOM software pre installed Floor space considerations also come into play when large numbers of servers are deployed especially in service provider environments which often must cope with limited floor space Densely packing servers into racks has proven to be a popular solution to this problem Sun s most successful product in this space is the Netra t1 server which requires only one rack unit or 1 75 inches of rack height and can fit into shallow 600 mm deep cabinets Manageability of Server Farms Manageability is a key consideration for any architecture that consists of a large number of components especially when the components are geographically disbursed or when Lights Out Management LOM facilities are setup and maintained This article examines a few important LOM datacenter manageability issues Change Management It is important to work out a strategy for upgrading or modifying many servers To choose an upgrade strategy ask the following questions a Will the application and operating system run successfully if you upgrade some of the servers while the remaining servers continue to run older versions of the software If this is the case it should be fairly easy to implement a procedure for upgrading the entire server farm during off peak hours perhaps
10. control of the port is given to the LOM device and this can cause modem connections to be lost If you connect the Serial A LOM port to a Terminal Server disable modem control on the Terminal Server port Manageability of Server Farms 3 m A Terminal Server or patch panel connected to a Terminal Server The pinouts for the Netra t1 serial ports correspond to the pinouts for the RJ45 ports on the Asynchronous Serial Interface Breakout Cable supplied by Cisco for use with the Cisco L2511 Terminal Server For terminals from other manufacturers you may need to make your own cross over null modem cable The pinouts are shown in TABLE 1 For EMC compliance all connectors or connector adaptors must be shielded and must use metal housing construction If you are using a Cisco L2511 Terminal Server and you are connecting the Netra t1 system to it using the Cisco Asynchronous Serial Interface Breakout Cable you can either connect the Breakout Cable directly to the Netra t1 server or you can connect the Breakout Cable to a patch panel and use the straight through patch cable supplied by Sun to connect the patch panel to the Netra t1 server You do not have to use the Netra t1 server with a Cisco Terminal Server For other Terminal Servers check the manufacturer s documentation to see if the pinouts of the serial ports on the Terminal Server match the pinouts of the Netra t1 serial ports If they do not match you must create a cable that dire
11. cts each pin on one of the Netra t1 serial ports to the corresponding pin in the Terminal Server s serial port For your convenience TABLE 1 provides the RJ45 pinouts where Pin 1 is on the left if the unit is viewed from the back TABLE 1 RJ45 Pinouts PIN FUNCTION RTS DTR TXD Signal Ground Signal Ground RXD DSR CTS D N OO a A N e The LOMlite Device The Netra t1 server contains a built in hardware component called the LOMlite device The Netra t 1400 1405 servers also contain the built in LOMlite device The LOMlite device provides remote management of the system over the Serial A port The LOMlite device is powered by auxiliary power so that you can monitor and 4 Planning for Large Configurations of Netra t1 Servers January 2001 control the server even when it is powered off or when the operating system is not running When the operating system is running LOMlite performs event reporting via the Solaris Operating Environment over the Serial A LOM port The LOMlite device monitors the status of the power supply unit PSU and fans in the system It provides a fault LED panel and three alarms to notify you of events or failures It also provides an automatic server restart ASR function which can reset the system in the event of a hard system hang LOMlite provides the capability to power up the system to return it to standby mode and to reset the host from the serial command interface Events such
12. ed X6967A Netra Telco 24 conversion kit for industry 72 rack 36U allowed 30U recommended X6968A 600mm rack conversion kit 16 Planning for Large Configurations of Netra t1 Servers January 2001 To mount a Netra t1 or Netra st D130 one RU storage unit into one of these racks you need one of the following rack mounting kits TABLE 11 Netra t1 server or Netra st D130 storage unit Rack Mounting Kit for StorEdge 72 Expansion Cabinet Description Quantity Part No Front slide 2 340 6215 Rear slide 2 340 6234 Cable bracket 1 340 6151 Thumbscrew bracket 2 340 6085 M4 8mm Phillips countersunk screw 4 240 3070 10 32 UNF screws 8 240 1207 M4 nut 4 240 1373 TABLE 12 Netra t1 server or Netra st D130 storage unit 19 inch Rack Mounting Kit Description Quantity Part No Front slide 2 340 6215 Rear slide 2 340 6234 Cable bracket 1 340 6151 Thumbscrew bracket 2 340 6085 M4 8mm Phillips countersunk screw 4 240 3070 10 32 UNF screws 8 240 1207 M4 nut 4 240 1373 TABLE 13 Netra t1 server or Netra st D130 storage unit 23 inch Rack Mounting Kit Description Quantity Part No Front slide 2 340 6209 Rear slide 2 340 6210 Cable bracket 1 340 6151 Thumbscrew bracket 2 340 6085 M4 8mm Phillips countersunk screw 4 240 3070 10 32 UNF screws 8 240 1207 M4 nut 4 240 1373 Rackmount Installation 17 TABLE 14 Netra t1 server or Netra st D130 storage unit 24 inch Rack Mounting Kit Description Quantity Part No Front
13. ences crites de Sun CETTE PUBLICATION EST FOURNIE EN L ETAT ET AUCUNE GARANTIE EXPRESSE OU IMPLICITE N EST ACCORDEE Y COMPRIS DES GARANTIES CONCERNANT LA VALEUR MARCHANDE L APTITUDE DE LA PUBLICATION A REPONDRE A UNE UTILISATION PARTICULIERE OU LE FAIT QU ELLE NE SOIT PAS CONTREFAISANTE DE PRODUIT DE TIERS CE DENI DE GARANTIE NE S APPLIQUERAIT PAS DANS LA MESURE OU IL SERAIT TENU JURIDIQUEMENT NUL ET NON AVENU S ca Please Adobe PostScript Recycle Planning for Large Configurations of Netra t1 Servers Scenario Many service providers want to use large server farms for application front ends such as Web and cache services This approach can result in benefits including cost savings and easy incremental scaling but it requires consideration of several key issues regarding the manageability and serviceability of large numbers of servers that may be geographically disbursed In addition this approach requires consideration of power cooling and installation issues related to densely populated racks of servers This wide ranging article addresses these topics and is intended to assist Sun customers who want to deploy large server farms consisting of Netra t1 servers Particular attention is given to the AC powered Netra t1 model 105 server Horizontal Scaling Issues Horizontal scaling is most appropriate for applications that do not maintain session state such as Web servers When an application does not maintain se
14. fter 30 seconds all the outputs in the Switched2 group turn on simultaneously Between the two power sequencers in a StorEdge 72 Expansion Cabinet there are a total of 16 AC outlets that you could use If you want to mount 32 Netra t1 units in the rack you can attach splitter cables part number 530 2264 01 to each of the 16 outputs thereby providing 32 AC power sources Thus each power sequencer provides power to a maximum of 16 Netra t1 servers This configuration is used successfully by many of Sun s customers However there are some issues that you should be aware of First you may only be able use this maximum configuration with high line voltage 180 to 240 volts Consider TABLE 5 which shows an example of the measured amps and watts drawn by a Netra t1 server under different input voltages These measurements were taken by Sun personnel TABLE 5 Netra t1 Model 105 Server Amperes and Watts Input Voltage Amperes Watts 90 0 95 85 6 100 0 85 84 5 120 0 70 84 5 180 0 51 82 6 200 0 46 81 7 240 0 39 81 9 Despite these particular measurements the rated current for a Netra t1 server is 1 5 amps at 100VAC This is a conservative value but it is worth examining the implications Each power sequencer is rated for a maximum of 24 amps In the configuration we are considering 16 Netra t1 servers are connected to a single power sequencer This poses no problem in the 180VAC to 240VAC range For example at 240VAC the total
15. nd watchdog tsdog 1M Sets watchdog parameters amp failure actions tsmonitor 1M Simple example alarm monitor process 6 Planning for Large Configurations of Netra t1 Servers January 2001 TABLE 2 Netra t Alarms amp LOMlite System Utilities tsstate 1M Gets state of PSU fans and watchdog clock tsunlock 1M Enables detach requests for tsalarm driver lomctl 1M Configure amp control the LOMlite lominfo 1M Returns environmental and configuration information lomprog 1M Reprogram the LOMlite with new firmware lom 7D LOM device driver lomlited 1M Controls LOM alarms and watchdog For a detailed description of these utilities see the man pages that accompany the Netra t Alarms LOMlite software CODE EXAMPLE 1 provides an example Netra t Alarms LOMlite control script This script uses the tsstate command within a loop which calls the function doalarm in order to set Alarm1 upon any fault condition Manageability of Server Farms 7 8 CODE EXAMPLE 1 Example Netra t Alarms LOMlite Control Script bin sh We set alarml for any fan failure supply failure or watchdog failure SSTATE tsstate TSCTL tsctl FAULTY faulty MONALARM alarml Define a function to set alarm when anything is faulty doalarm if S fanl SFAULTY o fan2 SFAULTY o Sfan3 SFAULTY o S fan4 SFAULTY o Ssupplya SFAULTY o Ssupplyb SFAULTY o Swatchdog SFAUL
16. ns of Netra t1 Servers January 2001 TABLE 8 Netra t1 model 100 server Maximum Design Values at Rated Nominal Voltage Voltage V 48 VDC Current A 21A Power W 100 W In rush current A Less than 20 A decaying to normal in 200 msec at 75 VDC cold start Rated current of 2 5 A system Rated voltage of 48 60 VDC Nominal system TABLE 9 Netra t1 model 100 server Measured Values Configuration 1 440MHz CPU 1 GByte Memory 4 memory Modules 1 CD ROM 2 1 18GByte 10K rpm disk drives 1 PCI Card QFE Running Sun VTS Voltage V 48 VDC Current A 1 63 A Power W 78 W In rush current A 7 32 A decaying to 3 A in less than 25 msec at 75 VDC cold start Cooling Issues All Netra servers use front to back cooling These are known as Type A devices Some products from Sun such as the Sun Enterprise 4500 server use side to side cooling These are known as Type B devices Front to back cooling is more efficient and makes it much easier to mount many devices in a single rack without encountering cooling problems If you intend to mount 32 Netra t1 servers in a 36U StorEdge 72 Expansion Cabinet the left over 4U of cabinet space should be trimmed off with panels This prevents warm air from flowing to the front of the rack and being recirculated which would Cooling Issues 15 reduce the efficiency of the cooling system and potentially contribute to overheating problems Panels for the S
17. ogie relative aux polices de caract res est prot g par un copyright et licenci par des fournisseurs de Sun Des parties de ce produit pourront tre d riv es des syst mes Berkeley BSD licenci s par l Universit de Californie UNIX est une marque d pos e aux Etats Unis et dans d autres pays et licenci e exclusivement par X Open Company Ltd Sun Sun Microsystems le logo Sun Sun BluePrints Netra Sun Professional Services Sun Enterprise Starfire et Solaris sont des marques de fabrique ou des marques d pos es de Sun Microsystems Inc aux Etats Unis et dans d autres pays Toutes les marques SPARC sont utilis es sous licence et sont des marques de fabrique ou des marques d pos es de SPARC International Inc aux Etats Unis et dans d autres pays Les produits portant les marques SPARC sont bas s sur une architecture d velopp e par Sun Microsystems Inc L interface d utilisation graphique OPEN LOOK et Sun a t d velopp e par Sun Microsystems Inc pour ses utilisateurs et licenci s Sun reconna t les efforts de pionniers de Xerox pour la recherche et le d veloppement du concept des interfaces d utilisation visuelle ou graphique pour l industrie de l informatique Sun d tient une licence non exclusive de Xerox sur l interface d utilisation graphique Xerox cette licence couvrant galement les licenci s de Sun qui mettent en place l interface d utilisation graphique OPEN LOOK et qui en outre se conforment aux lic
18. s that are involved with deploying densely populated racks of Netra t1 servers Particular attention was paid to the effects of in rush current during warm and cold starts and the importance of properly sizing the power sequencer capacity Acknowledgements Warren Reid contributed to the article Thanks to Cari Yuen Sean Wrycraft Bill Channell David Machado Neil Bird Peter Wilson Raj Natarajan Chin Cheng Richard Elling John S Howard Mark Garner and Bill Sprouse for their guidance and reviews Author s Bio Stan Stringfellow Stan Stringfellow is an independent author technical writer and software developer who is currently doing work for the Sun BluePrints program He holds a B A C S from UC San Diego and has written many manuals including the original software manuals for the Sun Enterprise 10000 also known as Starfire server He may be contacted at stan stringfellow com Conclusion 19
19. sers and licensees Sun acknowledges the pioneering efforts of Xerox in researching and developing the concept of visual or graphical user interfaces for the computer industry Sun holds a non exclusive license from Xerox to the Xerox Graphical User Interface which license also covers Sun s licensees who implement OPEN LOOK GUIs and otherwise comply with Sun s written license agreements RESTRICTED RIGHTS Use duplication or disclosure by the U S Government is subject to restrictions of FAR 52 227 14 g 2 6 87 and FAR 52 227 19 6 87 or DFAR 252 227 7015 b 6 95 and DFAR 227 7202 3 a DOCUMENTATION IS PROVIDED AS IS AND ALL EXPRESS OR IMPLIED CONDITIONS REPRESENTATIONS AND WARRANTIES INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY FITNESS FOR A PARTICULAR PURPOSE OR NON INFRINGEMENT ARE DISCLAIMED EXCEPT TO THE EXTENT THAT SUCH DISCLAIMERS ARE HELD TO BE LEGALLY INVALID Copyright 2001 Sun Microsystems Inc 901 San Antonio Road Palo Alto Californie 94303 Etats Unis Tous droits r serv s Ce produit ou document est prot g par un copyright et distribu avec des licences qui en restreignent l utilisation la copie la distribution et la d compilation Aucune partie de ce produit ou document ne peut tre reproduite sous aucune forme par quelque moyen que ce soit sans l autorisation pr alable et crite de Sun et de ses bailleurs de licence s il y en a Le logiciel d tenu par des tiers et qui comprend la technol
20. slide 2 340 6211 Rear slide 2 340 6212 Cable bracket 1 340 6151 Thumbscrew bracket 2 340 6085 M4 8mm Phillips countersunk screw 4 240 3070 10 32 UNF screws 8 240 1207 M4 nut 4 240 1373 TABLE15 Netra t1 server or Netra st D130 storage unit 600mm Rack Mounting Kit Description Quantity Part No Front slide 2 340 6213 Rear slide 2 340 6214 Cable bracket 1 340 6151 Thumbscrew bracket 2 340 6085 M4 8mm Phillips countersunk screw 4 240 3070 10 32 UNF screws 8 240 1207 M4 nut 4 240 1373 The cable bracket is provided to aid cable management at the rear of the system It is recommended that you mount units from the bottom of the rack to the top for maximum stability For step by step instructions on how to rackmount a Netra t1 server or a Netra st D130 storage unit see the Netra t1 and Netra st D130 Rackmount Installation guide part number 806 3856 11 18 Planning for Large Configurations of Netra t1 Servers January 2001 Conclusion This article examined several key remote management issues for server farms consisting of Netra t1 servers The Netra t Alarms LOMlite facilities were introduced including the LOMlite automatic server restart ASR function and the watchdog process This article examined the best ways to use these facilities to monitor and manage servers and provided a sample script that makes calls to Netra t Alarms LOMlite system utilities Consideration was also given to the power cooling and rack mounting issue
21. ssion state different servers can be assigned to handle requests from a single client during a single session This makes it easy to load balance user sessions efficiently across a server farm If an application maintains session state it may be more difficult to scale it across many servers and still use resources efficiently Since a large horizontally scaled solution necessarily consists of many individual servers by definition the system s overall reliability is reduced Simply adding more components increases the probability that some component will fail at any given point in time Given that reliability is critical in service provider environments it is important to construct a server farm out of highly reliable individual components The Netra t1 server is popular among service providers in part because of its inherent reliability and the fact that it is NEBS Level 3 certified as are all Netra server and storage products Note however that Sun qualifies individual Netra servers not racks of servers Serviceability is another important consideration in any architecture where many servers are deployed The Netra servers feature back end cabling and front end servicing This allows field personnel to replace server components such as disk drives quickly without detaching cables The Netra t1 server is mounted with a slide mechanism that allows the entire unit to be easily replaced after uncabling it Thus the server itself can
22. thin 50mS The maximum in rush current for a Netra t1 server is 56 amps upon a cold start and 100 amps upon a warm start Note that these numbers are significantly higher than the nominal steady state current for a Netra t1 server which tends to be less than one amp as shown above It is possible for in rush current to open circuit breakers In the configuration we are discussing eight Netra t1 servers are powered on simultaneously If this occurs as a warm start e g if the AC power goes off and comes back on automatically within 50mS and if the power is applied at the point where in rush current is maximized a transient current of 800 amps could occur This could potentially open a circuit breaker on the wall This issue may or may not be important for a particular site In many environments the service levels would permit you to simply wait a minute or so and then turn on the power sequencers with the key switches However if you have high availability requirements and are using full racks of Netra t1 servers you may need to consider this issue One potential solution is to use a power sequencer or similar unit that always applies power when the AC voltage is at the zero crossing point You can obtain such a unit from a third party supplier The circuit breakers in the power sequencers supplied with the StorEdge 72 Expansion Cabinet allow only 360 amps of in rush current If you are using these power sequencers and if your service
23. torEdge 72 Expansion Cabinet are available in a variety sizes such as 1U 2U 3U 4U and 5U You may want to order the optional redundant fan tray cooling package x option X9819A that can be housed at the top of the StorEdge 72 Expansion Cabinet The fans pull air upward through the top of the rack If space is limited at the rear of your rack it may be important to use a fan so that heat does not build up there The fan unit does not require any rack space You should calculate the overall heat generated by your racks so that you can size your cooling system appropriately To do this simply convert the power requirements figure described in Calculating Power Requirements above from Watts to BTU hour by multiplying the Watts figure by 3 415 For example if a rack requires 92 28 W the heat dissipated is 92 28 x 3 415 315 14 BTU hour Be sure to arrange your racks so that the warm air exhaust from one rack does not flow directly into the cool air intake area for another rack Any configuration you select must be tested and qualified to pass performance and agency regulations including EMI Rackmount Installation In addition to the StorEdge 72 Expansion Cabinet Sun also offers the following rackmount kits TABLE 10 Netra Rackmount Kits X6919A Netra Telco 19 conversion kit for industry 72 rack 36U allowed 30U recommended X6966A Netra Telco 23 conversion kit for industry 72 rack 36U allowed 30U recommend
24. tware now provides support for Netra alarms and LOMlite features To add this support to an existing Sun Management Center installation download the SunMC Netra server packages from http www sun com netra software You will need to install the agent module 25 MBytes for the generic module plus 5 MBytes for the Netra server packages on each Netra server to be monitored In addition you will need to install the server module 45 MBytes for the generic module plus 4 MBytes for the Netra server packages on each server or console that will perform monitoring tasks For more information see the Sun Management Center 2 x Software User s Guide and the Sun Management Center 2 x x Software Release Notes m Use a third party systems management tool such as HP Openview or Unicenter TNG It is unlikely you will use such a tool simply to manage a server farm However if you have standardized on one of these tools to manage your environment you can now download the SNMP MIB package that allows the tool to interface with the Netra alarms and LOMlite features The package is located at http www sun com netra software Support is also provided for BMC Patrol through Sun Professional Services M If you choose to write scripts to monitor and manage your Netra t1 server farm you can call the system utilities shown in TABLE 2 TABLE 2 Netra t Alarms amp LOMlite System Utilities tsalarm 7D Alarm device driver tsctl 1M Controls alarms a
25. xample an application might set an alarm condition if a daemon is not responding In this case remote management software possibly custom developed code would notice that the alarm condition has been set and take the appropriate action Note that there is no external physical alarm interface for the Netra t1 server and no relay contacts that attach to flashing lights Other Netra servers including the Netra t 1400 1405 server offer this feature The alarm conditions must be monitored by a tool such as Sun Management Center software or a proprietary tool developed using the API s and scripts provided Manageability of Server Farms 5 Choosing a Management Approach You have several options for taking advantage of the LOMlite technology in order to remotely manage a large farm of Netra servers m Use the provided UNIX utilities that interface with the Netra t Alarms LOMlite hardware This is probably the best choice for most service providers and it is the approach that is examined in this article m Write your own software programs using LOMlite UNIX ioctls This provides finer granularity of control and better performance But this approach is much more difficult to implement and it potentially ties you to a particular release of the operating system In addition the performance benefits are probably not critical for a homegrown remote management system m Use Sun Management Center software The Sun Management Center sof
26. ying Power to the Rack This article focuses on the StorEdge 72 Expansion Cabinet which provides 36 RU of rack space and includes two AC power sequencers It has the characteristics shown in TABLE 4 TABLE 4 StorEdge 72 Expansion Cabinet Height 187 cm 73 5 inches Width 61 cm 24 inches Depth 93 cm 36 5 inches Weight 159 kg 350 lbs empty Power 220 240 VAC 50 60 Hz Watts 5 400 maximum Amps 24 The 36 RU of rack space is over and above the space required by the power sequencers In theory you could mount 36 Netra t1 servers in a single rack However because of the power considerations described below it is recommended that you mount a maximum of 32 Netra t1 servers in a single StorEdge 72 Expansion Cabinet Each sequencer provides 10 AC outputs as follows m Two unswitched outputs It is recommended that you do not use these outputs in a rack of Netra t1 servers For your information however one of the outputs is an IEC320 AC outlet which is UL rated at 20 amps but European rated only at 16 amps The second output is rated at 10 amps Whenever power is applied both of these outputs are always on a The Switched1 group consists of four outputs each rated for 10 amps m The Switched2 group also consists of four outputs each rated for 10 amps Powering Densely Populated Racks 11 12 When you turn on the power sequencer with the key switch all of the outputs in the Switched1 group turn on immediately A
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