Discuss April 2011

discuss@lists.centos.org

312 participants
282 discussions

question on software raid
by Jerry Geis 04 Apr '11

04 Apr '11

dmesg is not reporting any issues. The /proc/mdstat looks fine. md0 : active raid1 sdb1[1] sda1[0] X blocks [2/2] [UU] however /var/log/messages says: smartd[3392] Device /dev/sda 20 offline uncorrectable sectors The machine is running fine.. raid array looks good - what is up with smartd? THanks, Jerry

7 6

cobbler installation of CentOS-5.5
by Timothy Murphy 04 Apr '11

04 Apr '11

I'm trying to install CentOS-5.5 on my new HP micro-server, which has no CD drive. I've set up cobbler and cobbler-web on my old server, and can access cobbler-web from my laptop. I have 3 queries about the installation. 1. Is there any advantage is using the 64-bit CentOS rather than 32-bit? 2. The CentOS OS seems to be available in 7 or 8 CDs. (I tried downloading the DVD ISO with ktorrent, but this was a complete failure. It started OK, but then created literally thousands of links to one file, which brought my server down, and left it in a state which was quite hard to clean up.) But how exactly do I "cobbler import" these? I see that for Fedora on my laptop I ran sudo cobbler import --path=/mnt/dvd --name=F14-i386 3. Is there actually a way of converting the 7 or 8 CD ISOs into a DVD ISO? I saw instructions that suggested concatenating them, and then running rsync against a DVD ISO, at <http://lists.centos.org/pipermail/centos/2011-January/104448.html>. I tried the site recommended, but could not access the DVD ISO. In fact, if I could access a DVD ISO, couldn't I download it directly? So what would be the point of this exercise? -- Timothy Murphy e-mail: gayleard /at/ eircom.net tel: +353-86-2336090, +353-1-2842366 s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland

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figuring out LogVol details for mount
by neubyr 03 Apr '11

03 Apr '11

Hi, I need to mount a LVM in rescue mode to create a new initrd image. I am not sure how do I fond out which LogVol is to be mounted. How do I find it out? In most of the configs I have used LogVol00 with ext3 filesystem which contains OS install. This particular system is not installed by me and I am not sure how do I find it out. I did try 'lvm lvs' command, but probably that's not the right command here. Any help? -- thanks, neuby.r.

8 16

certification
by marco van der grient 03 Apr '11

03 Apr '11

Hi there, Is there any change of certification on CentOS 5+ in the nearby future? Thanks for your time, Marco

2 1

Re: [CentOS] Download the repo DAG of CentOS 5.5
by aly.khimji＠gmail.com 03 Apr '11

03 Apr '11

I believe there is a rpm available from the DAG site, that will install the .repo file and setup everything you need to access the repo Ak ------Original Message------ From: Fidel Dominguez-Valero Sender: centos-bounces(a)centos.org To: centos(a)centos.org ReplyTo: CentOS mailing list Subject: [CentOS] Download the repo DAG of CentOS 5.5 Sent: Apr 3, 2011 2:12 PM hello somebody might help to create a script to download the repo DAG of CentOS 5.5 to my PC. I already did with OS, Update, and Extras packages. I want to do with DAG repository. I tried but I don't know much about scripts. Thanks Fidel _______________________________________________ CentOS mailing list CentOS(a)centos.org http://lists.centos.org/mailman/listinfo/centos Sent from my BlackBerry device on the Rogers Wireless Network

2 1

KVM Host Disk Performance
by Chuck Munro 03 Apr '11

03 Apr '11

Hello all, I'm having quite an interesting time getting up to speed with KVM/QEMU and the various ways of creating virtual Guest VMs. But disk I/O performance remains a bit of a question mark for me. I'm looking for suggestions and opinions .... This new machine has tons of disk space, lots of CPU cores and loads of RAM, so those are not issues. I currently have several software RAID-6 md's, each of which is about 700 GBytes. The md's are created as partitionable arrays, and I assign the resulting "raw" disk devices to each CentOS Guest OS, which then partitions the space according to its needs. Unlike using the more common "filesystem-in-a-file" method, the use of partitionable MD devices usually results in wasted disk space, but my aim is to provide the best performance possible with robust RAID. Is there a better-performing way of assigning disk space to Guest VMs? What about 'qcow2'? I understand its copy-on-write offers several advantages, but does it perform better than using partitionable md arrays or does the underlying filesystem overhead get in the way? Perhaps the native overhead of RAID-6 dual parity makes the whole question moot. Would the use of RAID-10 with hot spares be paranoid enough? I'm using 2 TByte drives which inherently have much greater chances of data errors, so I must keep data reliability in mind. I don't want to start a religious war over RAID and Guest VM disk methodology, but I have the luxury of trying various disk configurations until I get a reasonable balance between performance and reliability with these large drives. So many questions ... so much to learn. Lots of Googling around is quite useful but can lead to information overload :-) Cheers, Chuck

3 2

WD RE4-GP Dropped From Raid
by Gerhard Schneider 02 Apr '11

02 Apr '11

Did you check if you already have the G05 firmware on all RE4-GP? The G04 firmware is not suitable for RAID. http://forum.qnap.com/viewtopic.php?f=182&t=25057 GS -- Gerhard Schneider Institute of Lightweight Design and e-Mail: gs(a)ilsb.tuwien.ac.at Structural Biomechanics (E317) Tel.: +43 664 60 588 3171 Vienna University of Technology / Austria Fax: +43 1 58801 31799 A-1040 Wien, Gusshausstrasse 27-29 http://www.ilsb.tuwien.ac.at/~gs/

2 1

repeated local ephemeral to 80
by Michael D. Berger 02 Apr '11

02 Apr '11

On my CentOS box that I use mainly as a web server, I have iptables set to log and reject anything that I don't expect. So lately, I have getting things like this: Mar 29 17:27:20 mbrc20 kernel: IPT-DROP IN= OUT=lo SRC=192.168.9.20 DST=192.168.9.20 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=46910 DF PROTO=TCP SPT=56624 DPT=80 WINDOW=32792 RES=0x00 SYN URGP=0 OPT (0204400C0402080A4A26F7A50000000001030307) UID=0 that on at least one occasion repeated for every few seconds for more than three hours. The ephemeral source port keeps changing in an irregular manner. Any suggestions? Thanks, Mike

5 8

Cent OS clustering and Support.
by Kumar, Ranjan 02 Apr '11

02 Apr '11

Hi, We are a Channel product team within LSI and we are trying to add Cent OS 5.5 to our compatibility Matrix. We found out that LSI currently has a relationship with CentOS for another project on the Internal Storage division but not with the OS Certification team. We require some information on CentOS which will help us plan the deliverables. And considering the timelines we need to deliver at it will be great if someone from CentOS can help us out in this regard. If anybody else also can answer these in the mailing list, we would be grateful. The questions that we have are as follows:- 1) Cluster Support : * Does CentOS 5.5 provides native cluster support ? * Is there any cluster suite available for CentOS 5.5 ? * Can we use the cluster suite in CentOS 4 for 5.5. 2) Does CentOS have any self Certification tool which allows OEMs/Vendors to qualify the OS and post it in their compatibility matrix? One we start our qualification, we might need some help in resolving issues/defects on CentOS. Can we open a channel or Point of contact who will be able to help us out with such issues. I would also request to forward this email to the right forum if the mailing list we are sending to is not the appropriate one. Thanks and Regards. Kumar Ranjan LSI Technologies.

3 2

WD RE4-GP Dropped From Raid
by Steve Brooks 01 Apr '11

01 Apr '11

Hi All, I have a WD RE4-GP which dropped an Adaptec 51645 RAID controller. I ran a smartctl short test on the drive and it failed with a read error. So I ran the Western Digital's own diagnostic software (DLGDIAG), both the short and extended test on the drive and it passed with no errors. So I ran the smartctl short test again and again it failed. I then ran smartctl long test and that also failed at the same logical block address as the short test. Can anyone shed any light on this? Can I RMA the drive even if it passes Western Digital's own tests? Thanks in advance for any advice. Cheers, Steve

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Discuss April 2011