So you have used SVM to mirror your disk, and one of the two drives fails. Aren’t you glad you mirrored them! You don’t have to do a restore from tape, but you are going have to replace the failed drive.
Many modern RAID arrays just require you to take out the bad drive and plug [...]
Creating a properly offset slab of disk for Linux systems on your CLARiiON is not just a matter of creating a partition using the default fdisk values. The reason for this is that disk management utilities for Intel based systems generally write 63 sectors of metadata directly at the beginning of the LUN. The addressable [...]
At least in RHEL 4, the fdisk command does not support the creation of filesystems larger than 2TB. In order to get around it, you have to use the parted command. I found the basic info here, but this is the long and short of how to cut off a big ol’ slice of disk [...]
Getting Solaris 8 to light up a Qlogic QLA2310 Fibre Channel card using the SUNWqlc and SUNWqlcx drivers can be frustrating enough, but the headaches are only beginning if you want to connect it to a SAN and you don’t have all the right packages installed.
Last week, I installed the QLA2310 in a Sun Fire [...]
I’ve just returned from EMC training in MA, where we learned a wealth of information about how to use the array, but also some interesting background information about the device itself.
First, the name CLARiiON has some interesting history. Before EMC was EMC, it was Data General, who had a 16-bit minicomputer called the NOVA. DG [...]
Sun Microsystems likes the QLA 2310 Fiber Channel HBA. It’s only a 2Gig card, but it works with the Sun native driver, which makes it wonderful for us Solaris Administrators. Unfortunately, it does not integrate perfectly with EMC CLARiiON SANs because it does not register properly with Navasphere. Even if you manually register the host, [...]
The e2fsck will regularly force a check of a filesystem even if the filesystem is marked clean. By default, this happens on every twenty mounts or 180 days, whichever comes first.
The ext3 filesystem does this as well, which can be annoying if you have a very large filesystem and a short downtime window. Therefore, it’s [...]
Mounting filesystems in RHEL is pretty straightforward and easy. Occasionally, however, you will not want the filesystem to remain mounted all the time, but rather to automatically mount for a set period of time only when it is needed. Because of networking overhead, and the general unreliability of networks, NFS mounts are a good [...]
When you install RHEL, the filesystems are labeled for you. Usually you won’t have to mess with it anymore, but on occasion, you may want to change them to more accurately represent the data that is stored on that partition. If, for instance, you used to have all of your database files on a partition [...]
If you manage a UNIX system with a large number of directories that vary in size, chances are that you’ve needed to figure out which ones are using up the most disk space. Of course if the directories are user accounts, the best way to do this is to enable quotas and use the “repquota” [...]
Kids… DO NOT TRY THIS AT HOME! If this is not done exactly right, you will render your system unbootable and corrupt your data. That being said, under some circumstances you can take some space from your swap partition and add it to an unused one without initializing your entire disk. This is particularly useful [...]
For some reason RHEL 3 comes out of the box configured to see only the first Lun on a SCSI channel. This is usually not a problem, as the first Lun is all you care about, but in some instances, you will need to configure the SCSI module to see multiple Luns.
In this case [...]
There is a convention of thought amongst Oracle DBA’s that databases should never be installed on disks that are configured into a RAID 5 array. The argument goes, that since Oracle accesses and writes to random points within relatively large files, the overhead of constantly calculating block-level parity on these files is substantial, resulting in [...]
This summer we have been migrating a bunch of data to our shiny new InfoTrend EonStor A12F-G2221. With 1G battery backed cache, it’s a screaming box of disk, and it looks cool to boot. There is a gotcha though if you want to direct connect it to QLogic QLA2340 card on a REL 3 server. [...]
If you’re familiar with UNIX, you know that changing mount points is really pretty easy. All you have to do is go into “/etc/fstab”, “/etc/vfstab” (or whatever your flavor of UNIX happens to call its filesystem table) and change the mount directory.
If, for instance, you had a Solaris box, and you wanted to make the [...]
