apcupsd on RHEL5 / CentOS5

While the current Smart-UPS (aka SMT) range of UPS from APC has much fewer variables exposed in a way that is useful for fancy apcupsd usage (you’ll find apcupsd in EPEL), they are still amply sufficient for home use. Basically, the UPS gives an estimated time left at current load and the remaining battery level. At home these are anyway the only two readings I want to trigger scripts on.

fixing badly aligned storage

In the olden days, one would have to manually calculate[1] to get a file system (FS), in a logical volume (LV) that was part of a volume group (VG) living on a software RAID, properly aligned. I would get this calculation wrong in about 10% of the cases.

These days, modern Linux distributions like Fedora 14 and RHEL 6 parse hints from the storage.