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centos 5 reboot diagnosis
by Agnello George 25 Sep '09

25 Sep '09

Hi we use cent OS 5.2 on all our production server, just today one of or mail server had a reboot and we dont understand why ... usually we get a alert if a system was loaded up ... but this system just reboot .... may be it could be a power failure ...( is there any way to check this ) .. but that is the last optiopn i am guess as the server is in IDC . With dmidecode and biosdecode .. i just get server / bios info . In the Messages and Dmesgs ... i cant really pin pont the issue . Is there any thingi am not doing or any thing i am supposed to figure out the reson for this reboot. -- Regards Agnello D'souza

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Re: [CentOS] OT: What's wrong with RAID5
by nate 25 Sep '09

25 Sep '09

[re-sending with the right email address, hoping the first email won't make it through..] Fajar Priyanto wrote: > Hi all, > Sorry for the OT. > I've got an IBM N3300-A10 NAS. It runs Data Ontap 7.2.5.1. > The problem is, from the docs it says that it only supports either RAID-DP or RAID4. > What I want to achieve is Max Storage Capacity, so I change it from RAID-DP to RAID4, but with RAID4, the maximum disk in a RAID Group decrease from 14 to 7. In the end, either using RAID-DP or RAID4, the capacity is the same. It's the array's way of saying it's not really safe to operate a 14 disk RAID-4 group in the event of a drive failure. Also performance will suffer greatly with such a large data:parity drive ratio. NetApp RAID DP (what you have): http://www.netapp.com/us/library/white-papers/wp_3298.html > What's wrong with RAID5, is there any technical limitation with RAID5? Most onboard RAID controllers are absolute crap, RAID 5 isn't as easy to support as RAID1/RAID0, as extra processing time and code is needed for the parity stuff. I wouldn't use them for even RAID 1 though. If it's onboard, and I want RAID then I'll use software RAID. Unless it's a SCSI/SAS RAID controller often times those onboard RAID controllers are of decent quality. RAID 5 as implemented by most disk vendors does have issues at least with large SATA disks - Why RAID 5 stops working in 2009 - http://blogs.zdnet.com/storage/?p=162 A couple vendors that I know of - 3PAR(which I use) and Compellent don't suffer from this limitation because they virtualize the disks, I can't speak too much for Compellent's architecture but 3PAR doesn't RAID physical disks, they raid portions of each disk, when a disk fails, every disk in the system participates in rebuilding that failed set of arrays, which results in upwards of a 10x improvement in recovery time and 90%+ drop in system impact while the arrays are rebuilding. This virtualization also allows you to run multiple levels of RAID on the same spindles for different purposes. The likelihood of suffering a double disk failure on such a system during a RAID rebuild is probably quite a bit less than suffering a triple disk failure on a RAID-6 system which runs RAID on whole physical disks. At full system load my array can recover from a 750GB drive failure in less than 3 hours. Our previous array took nearly 30 hours to recover from a 300GB(SATA) drive failure. If on my array the disk is only half utilized, then it will take half the time to rebuild, as only written data is rebuilt, no point in replicating portions of the disk that haven't been used, though other vendors do this because they don't have the architecture to support sub-disk rebuilds. My own 200-disk array has more than 86,000 individual RAID arrays on it, most of them being RAID 5(5+1). Array management is automatic and transparent to the storage system I just tell it how big a volume I want and what type of data protection. For performance reasons I'm migrating my RAID 5(5+1) to 3+1 next year after I add more space. I miscalculated the growth of the big driver of space on the current system so I had to migrate to 5+1(RAID level migrations have no service impact either on my array). On my system there is roughly only a 9% performance drop from RAID 1+0 to RAID 5+0, so in many cases running RAID 5 on my array is about the same as RAID 1 on other arrays, it's that fast. RAID 6 has a pretty good performance hit vs RAID 5 due to the extra parity disk, on some arrays the performance hit is even greater as the array calculates parity twice, NetApp I think has as good a RAID 6 implementation as there is, though they can't get around writing the parity information to two different disks. nate

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logrotate and regular expressions
by Sol Fulop 25 Sep '09

25 Sep '09

I am trying to use logrotate to rotate our web logs for our various vhosted sites to cut down on space and rotate out old logs that are not necessary to keep around personally. What Im curious to find out, is how supported extended regular expressions is within the logrotate.conf file. More specifically, will logrotate be smart enough to decipher the following: /path/to/logs/access_log.www.*.(com|org|net|us) The filename format for my logs are: access_log.www.domain.com/net/org/us. Thank you in advance. Sol

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opensc - pkcs#11 smartcard support for EL4
by John R Pierce 25 Sep '09

25 Sep '09

does anyone know if any repositories have OpenSC built for EL4 ? I've been struggling with building this myself, trying to get an Aladdin eToken working with OpenSSL so we can use it for client authentication of an SSL session.

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Re: [CentOS] CentOS for non-tech user
by Les Mikesell 24 Sep '09

24 Sep '09

Sorin Srbu wrote: > >>> My mother runs CentOS on her computer at home. My wife does it on a >>> portable she lugs around on meetings. Why shouldn't CentOS be suitable > for >>> "home" users? CentOS's maintenance cycle alone got me all sweaty and hot >>> the first time I heard of it. ;-) >>> >> Yes, it's a very big plus. I'm comfortable using Fedora on my desktop, and > I >> use CentOS on my server, so with CentOS set to update regularly her >> maintenance needs should be minimal, which suits both of us very well ;-) > > Guessed as much. 8-) > > This is slightly OT, but does Fedora still have those six-months (or > thereabouts) cycles they had before? Yes - and for those suggesting ubuntu as better for a non-technical user I think the real question is whether the user will do any of their own changes (like adding new programs) and updates. If they do, ubuntu is probably a good choice. If they will ask you to do it for them, then it would be the system that you are most comfortable with maintaining. -- Les Mikesell lesmikesell(a)gmail.com

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Driver for Logitech QuickCam E2500 series webcam
by Andrew Allen 24 Sep '09

24 Sep '09

Does anybody know where I can find a driver for a Logitech E2500 webcam. I'm running CentOS 5 on my desktop and want to add a webcam for skype use. If I can yum install a driver from one of the repos that would be great. Andy

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problem with yum on centos4.7
by Timothy Chan 24 Sep '09

24 Sep '09

Hi all, Sorry for this newbie question. I am having a problem with yum on centos 4.7. When I try something like "yum update" I get the following error: file:///misc/CO4/updates/repodata/repomd.xml: [Errno 5] OSError: [Errno 2] No such file or directory: '/misc/CO4/updates/repodata/repomd.xml' Trying other mirror. Cannot open/read repomd.xml file for repository: update failure: repodata/repomd.xml from update: [Errno 256] No more mirrors to try. Error: failure: repodata/repomd.xml from update: [Errno 256] No more mirrors to try. I've tried "yum clean all" with no success. I'd be grateful for any help that I could get on this. Thanks. -tim

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Re: [CentOS] CentOS for non-tech user
by Anne Wilson 24 Sep '09

24 Sep '09

On Thursday 24 September 2009 13:37:54 Sorin Srbu wrote: > I'm guessing maintenance cycles. Anne? > > My mother runs CentOS on her computer at home. My wife does it on a > portable she lugs around on meetings. Why shouldn't CentOS be suitable for > "home" users? CentOS's maintenance cycle alone got me all sweaty and hot > the first time I heard of it. ;-) > Yes, it's a very big plus. I'm comfortable using Fedora on my desktop, and I use CentOS on my server, so with CentOS set to update regularly her maintenance needs should be minimal, which suits both of us very well ;-) Anne -- New to KDE4? - get help from http://userbase.kde.org Just found a cool new feature? Add it to UserBase

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Re: [CentOS] CentOS for non-tech user
by Anne Wilson 24 Sep '09

24 Sep '09

On Thursday 24 September 2009 13:34:24 Sorin Srbu wrote: > Just to be clear, my "there might be some repo(s) for this one" was meant > as Fedora generally speaking not, FC6 specifically. 8-) > OK - I tend to think of FC6 because it's the nearest, I think, to CentOS 5.x. Anne -- New to KDE4? - get help from http://userbase.kde.org Just found a cool new feature? Add it to UserBase

1 0

mdadm size issues
by Nathan Norton 24 Sep '09

24 Sep '09

Hi, I am trying to create a 10 drive raid6 array. OS is Centos 5.3 (64 Bit) All 10 drives are 2T in size. device sd{a,b,c,d,e,f} are on my motherboard device sd{i,j,k,l} are on a pci express areca card (relevant lspci info below) #lspci 06:0e.0 RAID bus controller: Areca Technology Corp. ARC-1210 4-Port PCI-Express to SATA RAID Controller The controller is set to JBOD the drives. All drives have the same partition size # fdisk -l Disk /dev/sda: 2000.3 GB, 2000398934016 bytes 255 heads, 63 sectors/track, 243201 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sda1 1 243201 1953512001 83 Linux .... I go about creating the array as follows # mdadm --create --verbose /dev/md3 --level=6 --raid-devices=10 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1 /dev/sdf1 /dev/sdi1 /dev/sdj1 /dev/sdk1 /dev/sdl1 mdadm: layout defaults to left-symmetric mdadm: chunk size defaults to 64K mdadm: size set to 1953511936K Continue creating array? As you can see mdadm sets the size to 1.9T. Looking around there was this limitation on older versions of mdadm if they are the 32 bit version. I am using the 64 bit most up to date version from Centos. If I go ahead and say yes create the array, mdadm says the following (I have zeroed the drives before adding them and creating the array) # mdadm --detail /dev/md3 /dev/md3: Version : 0.90 Creation Time : Thu Sep 24 23:48:32 2009 Raid Level : raid6 Array Size : 15628095488 (14904.11 GiB 16003.17 GB) Used Dev Size : 1953511936 (1863.01 GiB 2000.40 GB) Raid Devices : 10 Total Devices : 10 Preferred Minor : 3 Persistence : Superblock is persistent Update Time : Thu Sep 24 23:48:32 2009 State : clean, resyncing Active Devices : 10 Working Devices : 10 Failed Devices : 0 Spare Devices : 0 Chunk Size : 64K Rebuild Status : 0% complete UUID : cfa565db:4d0e07ca:b4d87a59:6e96cb06 Events : 0.1 Number Major Minor RaidDevice State 0 8 1 0 active sync /dev/sda1 1 8 17 1 active sync /dev/sdb1 2 8 33 2 active sync /dev/sdc1 3 8 49 3 active sync /dev/sdd1 4 8 65 4 active sync /dev/sde1 5 8 81 5 active sync /dev/sdf1 6 8 129 6 active sync /dev/sdi1 7 8 145 7 active sync /dev/sdj1 8 8 161 8 active sync /dev/sdk1 9 8 177 9 active sync /dev/sdl1 Anyone got any ideas? Nathan

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