SCSI hard drives used in servers are often prone to crashing after a power down. During long operation the hard drives acquire a fine build up from abrasion. This fine dust settles between the read/write head and the storage medium (drive plate) when the hard drive shuts off.

If a drive is turned off for a longer period of time for maintenance or storage, this can lead to "head sticking" where the head actually sticks to the surface of the media.

Then, when the drive is put into operation again, the head can be torn off. In some cases, the heads don't rip off but may become angled when the drive plate starts spinning. Light surface damage can occur at this time. Each time the drive is initialized during operation, the damage increases ... until it leads to an actual head crash.

Prevention of this problem includes the use of high quality drives and a regular total power down every 2-4 weeks. By regularly powering down, the dust "park-zones" are cleaned.

Please note: before you turn the system off make a complete data back up. 60% of all hard drive defects appear after a shut down!