Session 35 25 Reasons to Consider Linux Jeremiah Curtis Nat Foley Darren Rhoads.

Session 3525 Reasons to Consider

Linux

Jeremiah CurtisNat Foley

Darren Rhoads

25 ‘points of light’

• Overview• Boot• Filesystem• System Admin• Performance• Networking• SX Specific

1. What is Linux?2. Supported OS

versions3. Why NxTrend &

Linux4. Database servers

vs Client Desktop



5. GRUB

6. Run Levels

7. Controlling Services



8. Setup

9. /etc/fstab

10. RAID



11. Backups/Restore12. Bare Metal Recovery13. Software

Management with RPM

14. User Admin15. Printer Admin16. Cron17. /proc file system18. Kernel tuning



19. Sar / iostat

20. vmstat



21. Email

22. Samba / NFS

23. Client Communication Protocols



24. vid printing

25. report manager script

Overview: What is Linux? 1/25

• Linux – rhymes with ‘cynics’ • Open-source ‘unix’ – Linus Torvalds – ’91• World-wide developers – plug-in packages• Distributions – collections of packages

• Red Hat, SuSE, Turbolinux, Mandrake• Open-source = fast fixes to vulnerabilities• ‘free OS’ = ‘free speech’, and ‘free beer’• Software = depends on license• Support = not free

Overview: Supported OS Versions 2/25

• What NxTrend plans to support:– Red Hat Enterprise Linux 2.1 (AS)

– Red Hat Enterprise Linux 3.0 (AS) – future• Progress OpenEdge 10 service pack 1• Possibly Progress 9.1D09, 9.1E, summer 04?

Overview: Why NxTrend & Linux

3/25

• Low cost of ownership for customer base

• Added platform for flexibility

• NxTrend Corporate knowledge of unix

• Progress qualified/supported

DB Server vs Client Desktop

4/25

• NxTrend only supporting Linux as a Database server

• Not ‘Windows replacement” for client desktop

Boot: GRUB 5/25

• GRand Unified Bootloader• Select which Operating System for

multi-boot system• Select which Linux kernel to boot for

testing different kernels• Select which boot level for system

maintenance / repair• Change root password

Boot: Run Levels6/25

• 0 – Halt• 1, S, emergency – Single-user modes• 2 – multi-user, without NFS• 3 – Full multi-user• 4 – user-definable• 5 – Full multi-user with X11• 6 - Reboot

Boot: Controlling Services7/25

• ftp, telnet, http, cron, samba, and so on

• service – changes ‘now’– Start, stop, restart, status

• chkconfig – changes ‘future’– List, add, delete, turn on/off for boot

scripts

Filesystem: Setup8/25

• Disk Druid – Easiest way to set up file systems– Only available during installation

• fdisk

– Create partitions (FAT32, AIX, etc)

• Journaled File system– mke2fs – create file system with –j option– tune2fs – change to journaled with –j option

Filesystem: /etc/fstab9/25

/dev/sdc1 /rd ext3 defaults 1 2 /dev/sdc2 /db ext3 defaults 1 2 /dev/sdd1 /dump ext3 defaults 1 2 /dev/sdd2 /sort ext3 defaults 1 2

DEVICE

MOUNT_POINT

FS_TYPE

OPTIONS

DUMP_FREQ

FSCK_ORDER

•Set dump_freq and fsck_order to 0 for remote mount file systems, swap, cd-rom, floppy

Filesystem: RAID10/25

• Redundant Array of Inexpensive Disks– RAID 0: Striping– RAID 1: Mirroring– RAID 1+0: Striped FS on Mirrored disk sets– RAID 0+1: Mirrored FS on striped volume sets– RAID 5: Array with parity bit (never

recommended)• Hardware RAID highly recommended• Software RAID possible in RH Linux

– Only recommend RAID 0, 1, or 1+0 cat /proc/mdstat to see software RAID status

Sys Admin: Backup/Restore11/25

• cpio backups still standard– Must change the cpio options in scripts– Must change the tape device name in

scripts

• Exploring ‘pax’

Sys Admin: System Recovery

12/25• Recommend “Mondo”

– Bootable .iso image– Burn to CD or DVD – Boot to base OS from CD or DVD– Use to resize root file systems (/, /var,

/usr)

• Recovery diskette– Minimal bootable kernel and drivers

Sys Admin: Software Mgmt13/25

• RPM – Red Hat Package Manager– RPMs – distribution method for packages– Database of packages– Install, uninstall, update, verify, query

packages

Sys Admin: User Admin14/25

• useradd/userdel command• Each user has a private group ID

assigned• Group permissions meaningful - granular• /etc/skel – skeleton for new users’

$HOME• /etc/profile -> /etc/profile.d ->

/etc/bashrc -> ~/.bashrc -> ~/.bash_profile

Sys Admin: Printer Admin15/25

• LPRng – Available in RHEL 2.1– Updated BSD lpr print spooler

• CUPS – Common UNIX Printing System– Available in RHEL 3.0– Print spooler of choice for Red Hat– Will likely become NxTrend print spool

standard

Sys Admin: cron16/25

• Use common ‘cron/crontab’ commands– crontab –e to edit– crontab –l to list– crontab –r to remove (you didn’t see this!!)

• Can use specific crontab files for cyclic processes– /etc/cron.hourly, /etc/cron.daily,

/etc/cron.weekly, /etc/cron.monthly

Sys Admin: /proc file system17/25

• Virtual file system containing info about the kernel currently in use

• View files with ‘cat’ or ‘less’ or ‘more’

• DANGER - can modify certain settings on the fly

Sys Admin: Kernel Tuning18/25

• sysctl – configure kernel parameters– Display current settings (-a option = all)– Change settings at run-time (-w option)– No reboot necessary– Changeable parameters in /proc/sys– Change settings for future boots

• /etc/sysctl.conf is the config file

Performance: sar /iostat19/25

• Must install sysstat package• sarLinux 2.4.9-e.38smp (orthanc) 04/28/200403:56:36 PM CPU %user %nice %system %idle 03:56:42 PM all 0.25 0.00 0.79 98.96 03:56:48 PM all 0.42 0.00 1.12 98.46 03:56:54 PM all 0.71 0.00 0.79 98.5003:57:00 PM all 0.12 0.00 0.62 99.25 03:57:06 PM all 0.12 0.00 0.62 99.25 Average: all 0.32 0.00 0.79 98.88

• Cool options• -U ALL (show breakdown by CPU)• -o and –f (record/retrieve from file rather than

screen)

Performance: sar /iostat19/25 (cont)

• Must install sysstat package• iostatavg-cpu: %user %nice %sys %idle 4.79 0.00 2.29 92.92

Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtndev8-0 6.83 0.00 216.00 0 1296dev8-1 7.33 1.33 118.67 8 712dev8-2 0.00 0.00 0.00 0 0dev8-3 11.50 198.67 96.00 1192 576dev8-4 0.00 0.00 0.00 0 0

• Cool options• -x (display by partition)• -t (record the time-stamp or each iteration)

Performance: vmstat20/25

• Must install procps package (standard)• No special permissions necessary• Doesn’t count itself against numbers

[root@orthanc root]# vmstat 6 5 procs memory swap io system cpu r b w swpd free buff cache si so bi bo in cs us sy id 0 0 0 92 263928 282540 2907720 0 0 0 0 0 0 0 0 2 0 0 0 92 263928 282544 2907768 0 0 8 12 131 554 0 0 100 0 0 0 92 263928 282544 2907768 0 0 0 21 138 581 0 0 100 0 0 0 92 263928 282544 2907768 0 0 0 40 153 652 0 0 100 0 0 0 92 263928 282548 2907784 0 0 3 54 156 629 0 0 99

Networking: Email21/25

• MTA – Mail Transport Agent– sendmail

• MDA – Mail Delivery Agent– sendmail

• MUA – Mail User Agent

Networking: SAMBA / NFS22/25

• SAMBA– Windows: Standard drive/printer sharing

look/feel– Unix: Can mount shared Windows drive as a

file system• NFS

– Unix: Better protocol for Unix remote file system sharing

– Windows: Need the MS “Services for Unix” (SFU) installed on Windows machines

• Both– share one directory with NFS & SAMBA for all

computers

Networking: Client Communication Protocols

23/25

• SSH – Secure Shell– Encryption for data security

• FTP – File Transfer Protocol– Must be activated for install/upgrade

process

• Telnet – Terminal networking access– Must be activated if using telnet protocol

for character client software, i.e. InVue

SX Specifics: vid printing24/25

• Used to use ‘pg’ – not standard in RH

• Rewritten to use ‘less’ command

• Allows for in-stream decompression of gzip’d text files for viewing old logs

SX Specifics: report manager

25/25• Modify rptmgr startup script to use a

‘standard’ executable, rather than a ‘non-standard’ one

Additional Information

www.nxtrend.com– Customer care – matrix of which

Applications NxTrend has qualified and is supporting

– Future webinars on strategic Linux partnerships

www.redhat.com www.ibm.com/linux

http://www.nxtrend.com/

http://www.redhat.com/

http://www.ibm.com/linux

Questions?

Session 35 25 Reasons to Consider Linux Jeremiah Curtis Nat Foley Darren Rhoads.

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Transcript of Session 35 25 Reasons to Consider Linux Jeremiah Curtis Nat Foley Darren Rhoads.