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IP addressing migration
by Ivan Arteaga 14 Oct '06

14 Oct '06

Hi, I am changing the IP addressing in my centOS server which works as mail server. The question I have is, if I define the new IP addresses (sub-interfaces) on the server, can I work with both ranges at the same time despite I have only one default gateway configured? (on the old range) Or may I have two default gateways in centOS? --Ivan. -------------------------------------------------- Ivan Arteaga Grupo Regency Senior Network Consultant Phone: +507 205-8307 Email: <mailto:iarteaga@plazareg.com> iarteaga(a)plazareg.com <mailto:ivan.arteaga@sisa.com> ivan.arteaga(a)sisa.com "Look both ways before crossing the Net"

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migrating servers (advice)
by Ajay Sharma 13 Oct '06

13 Oct '06

Hi, I'm about to copy the contents of one server onto another. The "plan" that I've come up with is: 1) boot the new server with a live disc, partition accordingly 2) a big tar-over-ssh for the /boot, and root partitions (that's all there is) 3) adjust the fstab so that it'll find the new scsi partitions vs. the old ATA ones. 3) then chroot into the new system and run grub to initialize the bootloader. I'm switching a server from a single HD to a SCSI mirror on our new machine. So it has a different partition setup and I don't want to mess with resizing. Does that sound about right to get the machine booted? I'm sure there will be some other minor things but I can sort that out once I get the data over and the machine booted. --Ajay -- Satyajot (Ajay) Sharma REVShare System Administrator

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Re: [CentOS] Training Material: Books about linux but targeting Centos installations
by TimJowers＠Yahoo.Com 13 Oct '06

13 Oct '06

Erick, You need to contact Servin. Bar none they have the absolute best training manual for CentOS/RHEL. I have used it to teach before. Each chapter is a series of steps for the particular topic. Combine this with a theory book such as "Understanding the Linux Kernel" and some time on the computer and your students will walk out transformed. They have a book for admin, for Linux for tech pros, for Linux and BIOS, Linux Kernel, and some others I think. . http://www.servin.com/ TimJowers ----- Original Message ---- From: DM <mamwake(a)yahoo.com> To: CentOS mailing list <centos(a)centos.org> Sent: Friday, October 13, 2006 1:07:04 AM Subject: Re: [CentOS] Training Material: Books about linux but targeting Centos installations --- Erick Perez <eaperezh(a)gmail.com> wrote: > Hi, > I am about to give a training session in Linux, > using Centos 4.4 as a base. > I want to give my students (MS windows > administrators) printed books about > Linux and hopefully Centos based. It is a total of > 20 books. I'm also > interested in purchasing 20 copies of the DVD of > Centos 4.4 x86/x86_64 > distro. > > My initial search at amazon returned no useful > results. > > It can be RHEL 4, Centos 4 or fedora 4 based but I > really want them to be > Centos if possible, given the fact that I often > scracth RHEL intallations in > favor of Centos (i know is the same base, but I > would like to match the book > with the distro). > The books have to be focused to Linux administration > and installation (like > web,ssh.mail.etc). There is no need to cover > in-depth programming > (perl,bash,etc). > > Can anyone in the Centos community have some > references of these books/DVDs > for purchase? I have very good manual, geared to RHCE if you are interested contact me off-list.! > Thanks, > > > > -- > ------------------------------------------------------------ > Erick Perez > Panama Sistemas > Integradores de Telefonia IP y Soluciones Para > Centros de Datos > Panama, Republica de Panama > Cel Panama. +(507) 6694-4780 > ------------------------------------------------------------ > > _______________________________________________ > CentOS mailing list > CentOS(a)centos.org > http://lists.centos.org/mailman/listinfo/centos > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com _______________________________________________ CentOS mailing list CentOS(a)centos.org http://lists.centos.org/mailman/listinfo/centos

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Safely updating to 4.4 via yum (chicken)
by techlist 13 Oct '06

13 Oct '06

Hi guys: I saw the pelthora of threads where people had trouble moving to 4.4. So I'm chicken now and I was trying to wait for the dust to settle, I suppose it has and its been long enough I'm nervous about not upgrading. I need to do a a production server that is located in a data center far away so even more than normal I want a smooth upgrade. Can someone tell the what the concensous was on the best way to do the upgrade and avoid problems. From my notes I got: yum upgrade python-sqlite yum upgrade sqllite yum upgrade yum yum clean all yum update But at least one guy said his box was still hosed with duplicates and a broken bind after that. What's the method to upgrade 4.3-> 4.4 with the highest change of sucess? Thanks very much for the help. Scott

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Write performance with 3ware 9550
by Bowie Bailey 13 Oct '06

13 Oct '06

I have two identical servers. The only difference is that the first one has Maxtor 250G drives and the second one has Seagate 320G drives. OS: CentOS-4.4 (fully patched) CPU: dual Opteron 280 Memory: 16GB Raid card: 3ware 9550Sx-8LP Raid volume: 4-disk Raid 5 with NCQ and Write Cache enabled On the first server I have decent performance. Nothing spectacular, but good enough. The second one has about 1/3 the write speed. I can't find any difference between the systems. Both of them have the same stripe size, both have ext3 filesystems, both have write caching and NCQ turned on. I have already increased the read ahead setting to 16384 on both servers. I ran the tests like this: # sync; bonnie++ -d /iotest -s 50g -n 0 -b -f (I have removed some extra information from the reports for brevity) And here are the results for the two servers: ------Output------- --Input-- --Block-- -Rewrite- --Block-- --Seeks-- Machine Size K/sec %CP K/sec %CP K/sec %CP /sec %CP First 50G 62893 25 46763 12 160672 19 120.6 1 Second 50G 18835 7 44025 12 194719 24 122.8 1 As you can see, the write performance of the second server is terrible. Anyone have any suggestions of what I can look for? I keep thinking there must be something I tweaked on the first server that I forgot about for the second one, but so far I haven't been able to find it. Any suggestions appreciated! -- Bowie

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Apache DirectoryIndex
by Kirk Bocek 13 Oct '06

13 Oct '06

I'd like to change the DirectoryIndex document for just the DocumentRoot, leaving the default DirectoryIndex setting for all other directories. However, when I set DirectoryIndex in the <Directory "/var/www/html"> section of /etc/httpd/conf/httpd.conf it seems to set it for *all* directories. DirectoryIndex doesn't seem to be allowed in .htaccess either. Does anyone know how to set this? Thanks, Kirk Bocek

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RE: [CentOS] IP addressing migration
by Alex Palenschat 13 Oct '06

13 Oct '06

> Hi, > > I am changing the IP addressing in my centOS server which > works as mail server. The question I have is, if I define the > new IP addresses > (sub-interfaces) on the server, can I work with both ranges > at the same time despite I have only one default gateway > configured? (on the old range) Or may I have two default > gateways in centOS? > > --Ivan. Answer may be determined by whether those 2 ip are in the same subnet or not. If they are it will work fine, if not there are some workarounds: http://www.linode.com/wiki/index.php/Multiple_IPs alex

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Cluster Quorum Question/Problem
by Brandon Hall 13 Oct '06

13 Oct '06

Greetings all, I am in need of professional insight. I have a 2 node cluster running CentOS, mysql, apache, etc. I have on each system a fiber HBA connected to a fiber SAN. Each system shows the devices sdb and sdc for each of the connections on the HBA. I have sdc1 mounted on both machines as /quorum. When I right to the /quorum from one of the nodes, the file doesn't show up on the other. However, if I unmount and remount the device on the system that can't see the new file, the file shows up, but is broken/red and cannot be accessed by the node that couldn't see it in the first place. This works in both directions. Do I have things set up wrong? I'm so confused..... If they are sharing the same virtual drive on the same device in the same place, how can it not be the same on both systems??? Any help is appreciated! _________________________________________________________________ SearchYour way, your world, right now! http://imagine-windowslive.com/minisites/searchlaunch/?locale=en-us&FORM=WL…

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RE: [CentOS] Write performance with 3ware 9550
by Bowie Bailey 13 Oct '06

13 Oct '06

Kirk Bocek wrote: > Responding to several of your posts here. I understand your need for > stability, but can't you set StorSave down and see what it does to > your speed? I could, but I don't see the point. I have one machine with StorSave set at "Protect" which writes at 60MB/Sec. The other identical system which is also set to "Protect" only writes at 20MB/Sec. Therefore, there must be something else at work. As we speak, I have swapped the hard drives in these two systems and I am running another test. This will at least tell me if the problem is based in the hard drives & OS or elsewhere in hardware. > Some of my 95MB/Sec was achieved with some of the suggested ext3 > journal settings. Look back through my previous thread. > > Memory interleaving on my system (Supermicro X7DVL-E) is turned on > automatically when you install two pairs of memory sticks. With 16GB > on your system, I *assume* you have at least 4 sticks. Check the > manual and see if there is a BIOS setting. I found the interleaving settings in the BIOS. Both systems currently have it turned off, so I haven't touched it at this point. Once I have determined why the performance is so different between these two machines, I may experiment with that setting to see if it helps. Right now, I am not looking for maximum performance. I am just trying to determine why there is a 3x difference in write performance between two identical machines. -- Bowie

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RE: [CentOS] Write performance with 3ware 9550
by Bowie Bailey 13 Oct '06

13 Oct '06

Joshua Baker-LePain wrote: > On Thu, 12 Oct 2006 at 7:58pm, Bowie Bailey wrote > > > With NCQ off, I get these results: > > > > Version 1.03 ------Sequential Output------ --Sequential > > Input- > > --Random- > > -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- > > --Seeks-- > > Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec > > %CP /sec %CP Second 50G 20853 8 41899 11 > > 192713 23 116.9 1 > > > > Write performance increased by 2M/s and read performance decreased > > by 2M/s. > > > > What tweaks have you applied so far? I would expect a 4-drive array > > to be slower than an 8-drive array, but not this much! > > What's your StorSave profile set to? StorSave is set to Protection. Data integrity is very important on this system, so I need to leave it as is. Besides, I don't want to disable the data journaling after paying $100 for a BBU to protect it. :) -- Bowie

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