Using MRTG to Monitor I/O

Transcription

1 PS Series Groups Using MRTG to Monitor I/O Abstract This Technical Report describes how to use Multi Router Traffic Grapher (MRTG) to monitor the I/O between servers and PS Series group members running PS Series Firmware Version 3.1. TR1028 V1.0

2 Copyright 2007 EqualLogic, Inc. January 2007 EqualLogic is a registered trademark of EqualLogic, Inc. All trademarks and registered trademarks mentioned herein are the property of their respective owners. Possession, use, or copying of the documentation or the software described in this publication is authorized only under the license agreement specified herein. EqualLogic, Inc. will not be held liable for technical or editorial errors or omissions contained herein. The information in this document is subject to change. Your performance can vary. PS Series Firmware Version ii PS Series Groups: Using MRTG to Monitor I/O

3 Table of Contents Introduction... 1 Setting Up the Group and Server... 1 PS Group Instructions... 1 Windows Server Instructions... 1 Creating the I/O Monitoring Graphs... 3 Appendix A: Using a MIB Browser... 5 Appendix B: Modifying the mrtg.cfg File... 8 Documentation and Technical Support PS Series Groups: Using MRTG to Monitor I/O iii

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5 Introduction A PS Series group consists of one or more PS Series storage arrays connected to an Ethernet network. Each array (group member) has one to three network connections. You can install Multi Router Traffic Grapher (MRTG) on a Microsoft Windows server to create HTML-based graphs that enable you to monitor I/O to the group members. Analyzing the graphs over time can help you discover trends and the effects of changes to your storage or network environment. By running MRTG, you can address questions such as: What is the I/O activity of volumes and members? Which volumes are especially busy? Does I/O increase over time? What is the read/write ratio? This information can also help you choose a member RAID policy that optimizes the I/O for a specific volume or set of volumes. Setting Up the Group and Server To use MRTG to monitor PS Series group I/O, you need a server and a PS Series group running the V3.1 firmware. The instructions below are for a server running Windows, but MRTG also runs on UNIX and Linux. PS Group Instructions On the PS Series V3.1 group, configure the public SNMP read-only community string by doing either of the following: In the GUI, click: Group Configuration > SNMP tab > Add Enter the name public and click OK. Using the CLI, enter: grpparams snmp read-only-comms public Windows Server Instructions On the Windows server, follow these steps to set up and use MRTG: 1. Create the following directory: C:\www\mrtg PS Series Groups: Using MRTG to Monitor I/O 1

6 2. Install MRTG: a. Open a browser and go to the following website to obtain the installation instructions: Only the Prerequisites and Installing sections on the site are applicable to installing MRTG. b. Click Download (in the left frame). c. Download the latest MRTG zip file (it will be named something like mrtg zip) to the C:\ drive (root directory). d. Uncompress the zip file, which creates the C:\mrtg directory and subdirectories. 3. Install Perl from the following website: Make sure the server meets the Perl system requirements. 4. Download the MIBs and the MRTG configuration file from the EqualLogic website. a. Go to and log in to your customer support account. If you do not have an account, you can create one at this time. b. Navigate to firmware page on the EqualLogic Customer Support website: Customer Service Home tab > Downloads > PS Series Firmware > V3.1.1 c. In the Current Software table, click MIBS. d. Click Download and save the MIB file (named eqlmibs_v3[1].1.1-r52407.tgz) to the C:\ drive (root directory). e. Click Back. f. In the Current Software table, click MRTG Sample Config File. g. Click Download and save the file (named mrtg.zip) to the C:\mrtg \bin directory. 5. Unzip the MIB file and the mrtg.zip file in the directories in which you saved them. The MIB file and the mrtg.zip file are compressed using tar, a UNIX compression algorithm. To unzip the component files on a Windows server, use a program such as WinZip, PowerArchive, or tugzip. - Unzipping the MIB file will create a directory named eqlmibs. - Unzipping the mrtg.zip file will extract the mrtg.cfg file. 6. Copy the files eqlvolume.mib and eqlmember.mib from the eqlmibs directory to the C:\www\mrtg directory. 7. Gather the following information: - PS Series group name - Group IP address - Names of all the group members containing volumes 2 PS Series Groups: Using MRTG to Monitor I/O

7 - Member index for each member (see Appendix A: Using a MIB Browser) - Names of all the volumes whose I/O traffic you want to monitor - Volume index (see Appendix A: Using a MIB Browser) 8. Using Notepad or a similar text editor, open the file C:\mrtg-2.15\bin\mrtg.cfg. 9. Edit the mrtg.cfg file according to the embedded instructions (prefaced with ###TODO). See Appendix B: Modifying the mrtg.cfg File for an example. Now you can run the Perl script that will create graphs for the specified volumes and members, as described in Creating the I/O Monitoring Graphs. Creating the I/O Monitoring Graphs On the Windows server, follow these steps: 1. Open a Windows command prompt. 2. Change to the C:\mrtg \bin directory. 3. Enter the command: C:\mrtg \bin> perl mrtg mrtg.cfg Errors will appear. 4. Type Ctrl-C and enter the command again. You will see fewer errors. 5. Type Ctrl-C and enter the command again. You should see the following output and no errors: Daemonizing MRTG... Do Not close this window. Or MRTG will die Note: If you do not see this message after the third attempt, there may be an error in the mrtg.cfg file. Check the file and try again. At this point MRTG generates HTML files containing the I/O traffic data and places them in the C:www\mrtg directory. The following files are created, where group and volume indicate the actual group and volume names you used in the mrtg.cfg file: group_volume_data.html Throughput for the volume group_volume_ios.html I/O Activity for the volume group_volume_latency.html Latency for the volume group_member_latency.html Latency for the member Each graph shows the data over various time periods: 5-minute averages for a day, 30-minute averages over a week, 2-hour averages over a month, and daily averages over a year. 6. Optionally, create an index file to allow for easier viewing of the graphs by placing them all in one web page file. To create an index file: PS Series Groups: Using MRTG to Monitor I/O 3

8 a. Open a new command prompt. b. Go to the C:\mrtg \bin directory. c. Enter the following command to create the index file (index.htm): perl indexmaker --output index.htm mrtg.cfg Optionally, you can sort the graphs by title, name, or description by adding the appropriate sort option to the end of the indexmaker command. For example: perl indexmaker --output index.htm mrtg.cfg --sort=[title name descr] d. Copy the index file to the C:\www\mrtg directory. e. Open a browser and launch the index file, which looks similar to the following figure. Figure 1 Index File of MRTG Graphs To view historical details of a statistic, click the relevant graph. For example, clicking the graph labeled Latency for Member MidCab in Group BootGrp launches another web page displaying daily, weekly, monthly, and yearly latency graphs for the member. 7. Alternatively, you can integrate the index file and the graph files into a browser on your Web server. See the following URL for more information: 4 PS Series Groups: Using MRTG to Monitor I/O

9 Appendix A: Using a MIB Browser There are several MIB browsers available. You can search the Internet for one that meets your needs. The following example shows how to use the ireasoning MIB browser to extract the member index numbers and volume index numbers that you will use in the mrtg.cfg file. 1. Download and install the ireasoning MIB browser from 2. Open the ireasoning MIB browser. 3. In the Address field, enter the IP address of the PS Series group as shown in Figure 2. Figure 2 ireasoning MIB Browser: Enter group IP address 4. From the File menu, select Load MIB. 5. Navigate to the location of the EQL MIB files you downloaded from the EqualLogic support website (typically, C:\eqlmibs\). (See step 4 in Windows Server Instructions.) 6. Select the following MIB files (use the Control key to select more than one file) and click Open: eqlgroup.mib, eqlmember.mib, eqlvolume.mib 7. In the MIB tree, select the EQLGROUP-MIB folder. 8. From the Operations menu, select Walk. The Name/OID and Value fields in the right-hand panel will be populated with the group information. 9. Scroll through the list until you find the desired member names and volume names. PS Series Groups: Using MRTG to Monitor I/O 5

10 The Name/OID field contains the index numbers. Member index numbers are in the form.n.yyyyyyyyyy. For example, the group kagroup has one member named m1, highlighted in Figure 3. Its member index number is Figure 3 Member Index Numbers Volume index numbers are in the form.yyyyyyyyyy.z. The first part of the number is the index number of the member containing the volume data, and the second part of the number represents the volume, and these are incremented sequentially in the order the volumes were created. 6 PS Series Groups: Using MRTG to Monitor I/O

11 Figure 4 Volume Index Numbers For example, the volume index numbers for volumes vol1, vol2, vol3 and vol4 on member m1, highlighted in Figure 4, are as follows: vol vol vol vol Copy the member and volume index numbers; you will add them to the mrtg.cfg file as described in Appendix B: Modifying the mrtg.cfg File. PS Series Groups: Using MRTG to Monitor I/O 7

12 Appendix B: Modifying the mrtg.cfg File This appendix shows a modified mrtg.cfg file. The altered information is shown in bold font. In this example, the group is named groupc; it has one member named mem02, and one volume (for simplicity) named dbase2. The member index number is , and the volume index number is You will need to edit the mrtg.cfg file you downloaded from the EqualLogic support website, replacing variables such as %%GROUP_NAME%% and %%VOLUME_NAME%% with the names of your group, its members and volumes. There are four main sections to edit; you might need to copy and paste more sections into the file for all the members and volumes on your group. There is one section for members, and three sections for volumes (in the example, each section is shown as an area of boxed text). If you have multiple members, copy and paste the member section for each member sequentially and edit it accordingly. Also copy and edit the volume section for each volume. If you have multiple PS Series groups, you can create a separate mrtg.cfg file for each. If you plan to run MRTG on the same server for all your groups, give each configuration file a unique name: for example, mrtg_groupa.cfg and mrtg_groupb.cfg. When you run the Perl script to generate the HTML files (see Creating the I/O Monitoring Graphs on page 3), specify the appropriate configuration file for the group. Note: You will need to update your mrtg.cfg file whenever your group configuration changes; for example, when you: Add, rename, or delete volumes Clone a volume Add, rename, or remove members of the group Example 1 Sample mrtg.cfg File # # # Global Config Options # for UNIX # WorkDir: /home/http/mrtg # or for NT ###TODO:: Configure read only community string on the peer storage group. ###TODO:: Create the following directory on the host WorkDir: c:\www\mrtg ###TODO:: Copy eqlvolume.mib and eqlmember.mib to the working directory c:\www\mrtg LoadMIBs: c:\www\mrtg\eqlvolume.mib,c:\www\mrtg\eqlmember.mib ###TODO:: Replace the following variables # %%COMMUNITY%% with read only community string # %%GROUP_NAME%% with GroupName # %%GROUP_IP%% with Group IpAddress # %%VOLUME_NAME%% with Volume Name 8 PS Series Groups: Using MRTG to Monitor I/O

13 # %%VOLUME_INDEX%% with Volume Index. # ---- To get volume indicies, do a snmpwalk on eqliscsivolumename. Example: # %%MEMBER_NAME%% with Member Name # %%MEMBER_INDEX%% with Member Index # ---- To get member indicies, do a snmpwalk on eqlmembername. Example: # ### # Global Defaults EnableIPv6: no NoMib2: Yes RunAsDaemon: yes Interval: 5 Options[_]: growright kilo[_]: 1024 # Global options for volume pdu counters YLegend[_]: Pdus per Second ShortLegend[_]: Pdus/s Legend1[_]: Command Pdus Legend2[_]: Response Pdus LegendI[_]: Command Pdus LegendO[_]: Response Pdus Title[^]: SCSI counters for Volume PageTop[^]: <h1>scsi counters for Volume PageTop[$]: </h1> MaxBytes[_]: First volume section ###TODO:: Repeat the following block for all the volumes Target[groupc_dbase2_IOs]: eqliscsivolumestatscmdpdus &eqliscsivolumestatsrsppdus :public@ ::33:1:1:2 Title[groupc_dbase2_IOs]: dbase2 in Group groupc PageTop[groupc_dbase2_IOs]: dbase2 in Group groupc # Global options for Volume Data Counters YLegend[_]: MB per Second ShortLegend[_]: MB/sec Legend1[_]: Transmitted Bytes Legend2[_]: Received Bytes LegendI[_]: Transmitted LegendO[_]: Received Title[^]: Throughput for Volume PageTop[^]: <h1>throughput for Volume PageTop[$]: </h1> MaxBytes[_]: Second volume section ###TODO:: Repeat the following block for all the volumes Target[groupc_dbase2_data]: eqliscsivolumestatstxdata &eqliscsivolumestatsrxdata :public@ ::33:1:1:2 Title[groupc_dbase2_data]: dbase2 in Group groupc PageTop[groupc_dbase2_data]: dbase2in Group groupc Factor[groupc_dbase2_data]: # Global options for volume latency YLegend[_]: Milli Seconds PS Series Groups: Using MRTG to Monitor I/O 9

14 ShortLegend[_]: ms Legend1[_]: Read Latency in milli seconds Legend2[_]: Write Latency in milli seconds LegendI[_]: Read Latency LegendO[_]: Write Latency Title[^]: Latency for Volume PageTop[^]: <h1>latency for Volume PageTop[$]: </h1> MaxBytes[_]: Third volume section ###TODO:: Repeat the following block for all the volumes Target[groupc _dbase2_latency]: eqliscsivolumestatsreadlatency &eqliscsivolumestatswritelatency : Title[groupc _ dbase2_latency]: dbase2in Group groupc PageTop[groupc _ dbase2_latency]: dbase2in Group groupc # Global options for member latency YLegend[_]: Milli Seconds ShortLegend[_]: ms Legend1[_]: Read Latency in milli seconds Legend2[_]: Write Latency in milli seconds LegendI[_]: Read Latency LegendO[_]: Write Latency Title[^]: Latency for Member PageTop[^]: <h1>latency for Member PageTop[$]: </h1> MaxBytes[_]: Member section ###TODO:: Repeat the following block for all the members Target[groupc_ mem02_latency]: & : public@ ::33:1:1:2 Title[groupc_mem02_Latency]: mem02 in Group groupc PageTop[groupc_ mem02_latency]: mem02 in Group groupc 10 PS Series Groups: Using MRTG to Monitor I/O

15 Documentation and Technical Support Visit the EqualLogic Customer Service website, where you can download the latest documentation and firmware. You can also view FAQs, the Knowledge Base, and Technical Reports and submit a service request. EqualLogic PS Series storage array documentation includes the following: Release Notes. Provides the latest information about PS Series storage arrays and groups. QuickStart. Describes how to set up the hardware and start using a PS Series storage array. Group Administration. Describes how to use the Group Manager GUI to manage a PS Series group. This manual provides comprehensive information about product concepts and procedures. CLI Reference. Describes how to use the Group Manager command line interface to manage a group and individual arrays. Hardware Maintenance. Provides information on maintaining the PS Series storage array hardware. To report a problem or to get access to the resources available on the Customer Support website, go to and click LOGIN. If you do not already have an account, you can request one here. Once you are logged in, click Log a Case to report a problem. To report an urgent issue, please call us at and speak with a member of the Customer Support team. If you have any comments or suggestions related to this technical report, please send them to techreports@equallogic.com PS Series Groups: Using MRTG to Monitor I/O 11