From ruprech at jilau1.colorado.edu Tue Aug 10 14:33:47 2010 From: ruprech at jilau1.colorado.edu (Peter Ruprecht) Date: Tue, 10 Aug 2010 08:33:47 -0600 Subject: 16-disk SW RAID-6 on RHEL? Message-ID: <4C61634B.4090502@jilau1.colorado.edu> Hi everyone, I could use a little advice. I'm considering setting up a 16-disk software RAID-6 system for use as a samba fileserver. The disks would be 2TB SATA in an external enclosure attached via SAS to the server (RHEL5, 2x Xeon E5420 processors with 4 cores, 16 GB RAM). I have done software RAID-5 with 6 disks and gotten satisfactory performance, but has anyone else tried SW RAID on a bigger scale? Would that just be nuts? So why not just buy a HW RAID system? Well, in this case cost is a big issue. Also, in the past I've had some issues with RAID controllers freaking out leaving all the data inaccessible, which I think is less likely with SW RAID. Finally, is there a reasonable RH-compatible alternative to xfs for a 16TB+ filesystem? Or is xfs now less iffy than it was a few years ago? Thanks in advance, Peter Ruprecht From rvandolson at esri.com Tue Aug 10 14:50:51 2010 From: rvandolson at esri.com (Ray Van Dolson) Date: Tue, 10 Aug 2010 07:50:51 -0700 Subject: 16-disk SW RAID-6 on RHEL? In-Reply-To: <4C61634B.4090502@jilau1.colorado.edu> References: <4C61634B.4090502@jilau1.colorado.edu> Message-ID: <20100810145050.GA4756@esri.com> On Tue, Aug 10, 2010 at 07:33:47AM -0700, Peter Ruprecht wrote: > Hi everyone, > > I could use a little advice. I'm considering setting up a 16-disk > software RAID-6 system for use as a samba fileserver. The disks would > be 2TB SATA in an external enclosure attached via SAS to the server > (RHEL5, 2x Xeon E5420 processors with 4 cores, 16 GB RAM). > > I have done software RAID-5 with 6 disks and gotten satisfactory > performance, but has anyone else tried SW RAID on a bigger scale? Would > that just be nuts? > > So why not just buy a HW RAID system? Well, in this case cost is a big > issue. Also, in the past I've had some issues with RAID controllers > freaking out leaving all the data inaccessible, which I think is less > likely with SW RAID. > > Finally, is there a reasonable RH-compatible alternative to xfs for a > 16TB+ filesystem? Or is xfs now less iffy than it was a few years ago? I don't like going over 10 disks or so in a RAID-set, but maybe I'm old school. You definitely would want to do RAID-6 with that many... these days processors are plenty beefy enough to handle parity calculations with that many spindles, but keep in mind your rebuild times are going to be pretty long .. 14 disks to completely read... I think I'd go with two 8 disks RAID-6 arrays (and definitely have a spare ready), but I could be on the conservative side. :) Ray From trevor.hemsley at codefarm.com Tue Aug 10 19:43:37 2010 From: trevor.hemsley at codefarm.com (Trevor Hemsley) Date: Tue, 10 Aug 2010 20:43:37 +0100 Subject: 16-disk SW RAID-6 on RHEL? In-Reply-To: <4C61634B.4090502@jilau1.colorado.edu> References: <4C61634B.4090502@jilau1.colorado.edu> Message-ID: <4C61ABE9.4050905@codefarm.com> Be aware that RHEL5.5 still has this bug. http://www.issociate.de/board/post/455533/RAID6_mdadm_--grow_bug?.html Peter Ruprecht wrote: > Hi everyone, > > I could use a little advice. I'm considering setting up a 16-disk > software RAID-6 system for use as a samba fileserver. The disks would > be 2TB SATA in an external enclosure attached via SAS to the server > (RHEL5, 2x Xeon E5420 processors with 4 cores, 16 GB RAM). > > I have done software RAID-5 with 6 disks and gotten satisfactory > performance, but has anyone else tried SW RAID on a bigger scale? > Would that just be nuts? > > So why not just buy a HW RAID system? Well, in this case cost is a big > issue. Also, in the past I've had some issues with RAID controllers > freaking out leaving all the data inaccessible, which I think is less > likely with SW RAID. > > Finally, is there a reasonable RH-compatible alternative to xfs for a > 16TB+ filesystem? Or is xfs now less iffy than it was a few years ago? > > Thanks in advance, > Peter Ruprecht > > -- > redhat-sysadmin-list mailing list > redhat-sysadmin-list at redhat.com > https://www.redhat.com/mailman/listinfo/redhat-sysadmin-list -- Trevor Hemsley Infrastructure Engineer ................................................. * C A L Y P S O * 4th Floor, Tower Point, 44 North Road, Brighton, BN1 1YR, UK OFFICE +44 (0) 1273 666 350 FAX +44 (0) 1273 666 351 ................................................. www.calypso.com This electronic-mail might contain confidential information intended only for the use by the entity named. If the reader of this message is not the intended recipient, the reader is hereby notified that any dissemination, distribution or copying is strictly prohibited. * P * /*/ Please consider the environment before printing this e-mail /*/ From senthilprabu.s at nsn.com Wed Aug 11 15:06:02 2010 From: senthilprabu.s at nsn.com (S, Senthilprabu (NSN - IN/Bangalore)) Date: Wed, 11 Aug 2010 23:06:02 +0800 Subject: User defined roles on Linux Message-ID: Hello All, I am a newbie to Linux and SELinux as well. So apologize me if my question is stupid. All these days, I have been playing with Solaris. Have implemented user profiles and associated them with roles using RBAC on Solaris to facilitate set of users to run my application. Users assuming my role can only start, stop and troubleshoot application whereas not possible to execute any other commands. Now after RHEL 5.5 migration, I am trying to implement similar roles here too. After running through various RHEL manuals I assume that SELinux can be used to define RBAC roles to some extend, even though its main feature is to implement Mandatory Access Control (MAC). I see few pre-defined roles like sysadm_r and staff_u. Now my question is it possible to create user defined roles on RHEL 5.5 using SELinux and assign it to shared os accounts?. If possible but not through SELinux, please let me how it can be done?. Thanks in advance, Senthil Prabu.S From root at nachtmaus.us Wed Aug 11 15:53:31 2010 From: root at nachtmaus.us (dtklein) Date: Wed, 11 Aug 2010 15:53:31 +0000 Subject: User defined roles on Linux In-Reply-To: References: Message-ID: <1014697778-1281542011-cardhu_decombobulator_blackberry.rim.net-1045644042-@bda392.bisx.prod.on.blackberry> Many places use sudo and groups to provide RBAC capabilities. In general, one is allowed to execute a command with raised privilege if they meet the union of (command,user/group,machine) as defined in the sudoers file (or even better, put in the patch to mate-up sudo to LDAP). -- david t. klein Cisco Certified Network Associate (CSCO11281885) Linux Professional Institute Certification (LPI000165615) Redhat Certified Engineer (805009745938860) Quis custodiet ipsos custodes? -- Sent on the Sprint? Now Network from my BlackBerry? -----Original Message----- From: "S, Senthilprabu (NSN - IN/Bangalore)" Sender: redhat-sysadmin-list-bounces at redhat.com Date: Wed, 11 Aug 2010 23:06:02 To: Reply-To: redhat-sysadmin-list at redhat.com Subject: User defined roles on Linux Hello All, I am a newbie to Linux and SELinux as well. So apologize me if my question is stupid. All these days, I have been playing with Solaris. Have implemented user profiles and associated them with roles using RBAC on Solaris to facilitate set of users to run my application. Users assuming my role can only start, stop and troubleshoot application whereas not possible to execute any other commands. Now after RHEL 5.5 migration, I am trying to implement similar roles here too. After running through various RHEL manuals I assume that SELinux can be used to define RBAC roles to some extend, even though its main feature is to implement Mandatory Access Control (MAC). I see few pre-defined roles like sysadm_r and staff_u. Now my question is it possible to create user defined roles on RHEL 5.5 using SELinux and assign it to shared os accounts?. If possible but not through SELinux, please let me how it can be done?. Thanks in advance, Senthil Prabu.S -- redhat-sysadmin-list mailing list redhat-sysadmin-list at redhat.com https://www.redhat.com/mailman/listinfo/redhat-sysadmin-list From nitin.gizare at wipro.com Mon Aug 16 06:47:50 2010 From: nitin.gizare at wipro.com (nitin.gizare at wipro.com) Date: Mon, 16 Aug 2010 12:17:50 +0530 Subject: Clarification On top command Message-ID: Hello We use top command for checking system performance and many found that lot of memory is cached like one below Cpu(s): 28.2%us, 0.1%sy, 0.0%ni, 71.7%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 74175192k total, 73199960k used, 975232k free, 910828k buffers Swap: 104856244k total, 1565532k used, 103290712k free, 65612288k cached Can some body help us understand what is really cached? Is this available for required process on demand? Unable to get clear info about this. Many thanks in advance. Rgds Nitin -------------- next part -------------- An HTML attachment was scrubbed... URL: From nitin.gizare at wipro.com Mon Aug 16 08:44:18 2010 From: nitin.gizare at wipro.com (nitin.gizare at wipro.com) Date: Mon, 16 Aug 2010 14:14:18 +0530 Subject: Clarification On top command Message-ID: Hello We use top command for checking system performance and many found that lot of memory is cached like one below Cpu(s): 28.2%us, 0.1%sy, 0.0%ni, 71.7%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 74175192k total, 73199960k used, 975232k free, 910828k buffers Swap: 104856244k total, 1565532k used, 103290712k free, 65612288k cached Can some body help us understand what is really cached? Is this available for required process on demand? Unable to get clear info about this. Many thanks in advance. Rgds Nitin -------------- next part -------------- An HTML attachment was scrubbed... URL: From ozgurkuru at gmail.com Mon Aug 16 09:13:42 2010 From: ozgurkuru at gmail.com (=?ISO-8859-1?Q?=D6zg=FCr_KURU?=) Date: Mon, 16 Aug 2010 12:13:42 +0300 Subject: Clarification On top command In-Reply-To: References: Message-ID: > > Hello > > > > We use top command for checking system performance and many found that lot > of memory is cached like one below > > > > Cpu(s): 28.2%us, 0.1%sy, 0.0%ni, 71.7%id, 0.0%wa, 0.0%hi, 0.0%si, > 0.0%st > > Mem: 74175192k total, 73199960k used, 975232k free, 910828k buffers > > Swap: 104856244k total, 1565532k used, 103290712k free, 65612288k cached > > > > Can some body help us understand what is really cached? Is this available > for required process on demand? > > Unable to get clear info about this. > > > > Many thanks in advance. > > > > Rgds > > Nitin > > > Yes, this is available for requiered process on demand. You can find detail from http://www.faqs.org/docs/linux_admin/buffer-cache.html -- ?zg?r Kuru Grou.PS Server Admin www.ozgurkuru.net www.ozgurkuru.com.tr -------------- next part -------------- An HTML attachment was scrubbed... URL: From nitin.gizare at wipro.com Mon Aug 16 09:39:58 2010 From: nitin.gizare at wipro.com (nitin.gizare at wipro.com) Date: Mon, 16 Aug 2010 15:09:58 +0530 Subject: Clarification On top command In-Reply-To: References: Message-ID: Thanks. Rgds Nitin ________________________________ From: redhat-sysadmin-list-bounces at redhat.com [mailto:redhat-sysadmin-list-bounces at redhat.com] On Behalf Of ?zg?r KURU Sent: Monday, August 16, 2010 2:44 PM To: redhat-sysadmin-list at redhat.com Subject: Re: Clarification On top command Hello We use top command for checking system performance and many found that lot of memory is cached like one below Cpu(s): 28.2%us, 0.1%sy, 0.0%ni, 71.7%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 74175192k total, 73199960k used, 975232k free, 910828k buffers Swap: 104856244k total, 1565532k used, 103290712k free, 65612288k cached Can some body help us understand what is really cached? Is this available for required process on demand? Unable to get clear info about this. Many thanks in advance. Rgds Nitin Yes, this is available for requiered process on demand. You can find detail from http://www.faqs.org/docs/linux_admin/buffer-cache.html -- ?zg?r Kuru Grou.PS Server Admin www.ozgurkuru.net www.ozgurkuru.com.tr -------------- next part -------------- An HTML attachment was scrubbed... URL: From t.baer at dokom21.de Mon Aug 16 18:03:55 2010 From: t.baer at dokom21.de (t.baer at dokom21.de) Date: Mon, 16 Aug 2010 20:03:55 +0200 Subject: =?ISO-8859-1?Q?AUTO=3A_Torsten_B=E4r_ist_au=DFer_Haus=2E_=28R=FCckkehr_am?= =?ISO-8859-1?Q?_17=2E08=2E2010=29?= Message-ID: Ich bin bis 17.08.2010 abwesend Guten Tag und vielen Dank f?r Ihre Nachricht. Leider bin ich zurzeit au?er Haus. Ab dem 17.08.2010 bin ich wieder f?r Sie da. Ihre E-Mail wird nicht automatisch weitergeleitet, daher werde ich Ihre Mitteilung erst nach meiner R?ckkehr bearbeiten. In dringenden F?llen wenden Sie sich gerne an meine Vertretung Herr Jan Welte unter der Rufnummer 0231.930-94 03 oder per E-Mail j.welte at dokom21.de. 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