RHEL

For the last few weeks I've been fighting a problem with my RHEL5 system running VMware Workstation 5.5.  I'm primarily a Linux user and barely even fire up my Windows XP system, however, every now and then I need Windows for something at work and so I use VMware Workstation 5.5 to run the copy of WIndows XP that came with my Dell laptop.  This has always worked well and I've been doing this for yearsm, however, recently a problem cropped up that was annoying me to no end. Continue reading "VMware Workstation Hangs on RHEL5"

At work we have and IBM Bladecenter chassis with several HS20 blades running RHEL4 connected to a EMC Clariion CX700 storage array.  These blades have no internal storage and thus do Boot-from-SAN and obviously have their root volume located on the SAN as well.  Back when these systems were running RHEL3 I had hacked up a mkinitrd based on a Whitepaper from EMC that would include PowerPath within the initial ramdisk so that the root volume was also protected from path failures.  This worked reasonably well for many years but eventually we decided to migrate to RHEL4 and move the systems to dm-multipath.  Unfortunately dm-multipath over root is not supported by RHEL4 (I've been told that this is not an issue in RHEL5 but haven't tested it yet) so I set off to once again "do my own thing".  How hard could it be anyway?

(Updated Sep 22nd, 2007) Continue reading "RHEL4 dm-multipath on root HOWTO"

Today I was trying to install a new application on one of our web servers at the office that required PHP5.  Unfortunately that box was running RHEL3 and because of some third-party application certification requirement we really couldn't upgrade it.  Of course I could always just compile and install PHP5 from scratch, but that didn't seem to compelling to me.  Maintaining PHP4 on that box had always been troublesome anyway since one application always required the php-snmp module and Redhat does not officially povide this RPM.  I've always had to download the src RPM, edit the spec file to enable snmp, and build my own php-snmp RPM.  I decided that simply installing PHP5 RPM's might be a solution unfortunately a quick search didn't turn up any prebuilt RPMS for RHEL3. Continue reading "PHP5 on RHEL3"

In my invovlement on various mailing lists the subject of SAN multipath support for RHEL Linux seems to come up on a regular basis.  Until recently there were a multitude of options from various vendors, from failover support in the qla23xx driver, to proprietary modules from EMC, IBM, and HP such as PowerPath, RDAC, and SurePath.  For those people lucky enough to have active/active arrays you could even sometimes use the md multipath feature, however, those of us with active/passive array in many cases had only one fully working option.

With the release of RHEL4 U2-beta that's starting to change as Redhat has included all of the components of the new disk mapper based multipath support and this week I decided to give this new support a spin and see how it works with our EMC Clariion arrays at work.

Continue reading "Testing dm-multipath on RHEL4 U2-beta"

In RHEL4 it seems that Redhat/LSI Logic/Dell made the decision to include only the megaraid_mbox driver which doesn't include support for many older, yet popular hardware RAID systems, such as the Dell PERC2/DC based systems.  A few months ago I posted on the RHEL4 mailing lists my experiences installing RHEL4 on a system with such a card.  Since that time I've received quite a few emails asking about the procedure so I've decided to document it here.  This is not a perfect step-by-step guide, but should provide enough information to get a system installed.  It does require having another RHEL4 system so that you can compile the required kernel modules. Continue reading "Installing RHEL4 on Systems with Legacy Megaraid Drivers"