On 04/26/2010 10:09 PM, Ziemowit Pierzycki wrote: > I'm having an issue with my server. After successful installation of > F12 the system works normally for a while and then seems like all IO > operations cease. I am not able to access anything from the disk so > only the cached commands work. The CPU utilization is very low while > load average is through the roof along with IOWAIT pegged at close to > 100%. There is no disk activity at all. There are no errors > anywhere. Everything seems to be in order. > > I think this is related to the software RAID I setup on the system. I > have four 1 TB Western Digital Green drives configured using BIOS > configuration into RAID10. I'm just not sure what the heck is going on. > > I'm not sure this is motherboard/CPU/memory related because I tried it > with two different computers and the only thing that I moved between > them were the drives. Any ideas how I could troubleshoot this further? > > -- > Thank you, > > Ziemowit Pierzycki Don't know if this is your problem, but some motherboards do not like 'Green' drives running Linux. What can happen, is that the drives go to sleep when inactive. All green drives do this to save power. However, depending upon BIOS, disk driver, and kernel version, the system is not able to wake the drives back up when needed. The USB/scsi driver in RHE 5.2 (kernel 2.6.18) cannot wake up a green drive, for example. We had several customers in a co-location set up USB based drives for backups. The backups failed every day until we figured out what was happening. It would always work during testing, but never from the cron job. However, if the USB device was unplugged, and plugged back in, thus spinning up the drive manually, right before the cron job started, everything worked as desired. We also experienced a catastrophic failure of a critical ISCSI/RAID device due to 'green drives'. That's what we get for buying the device empty and putting cheap drives in it. Of course, we didn't read the manufacturers release notes either. Those notes, we later discovered, specifically forbade 'green' drives. Bottom line is this: The kernel needs to know how to wake up a drive in sleep mode. Sometimes 'green' drives are not friendly to Linux systems, and are not recommended for production RAID devices. Be sure to check with the manufacturer before putting them in. All that being said, modern kernels above 2.6.20 should work fine, so it may be a BIOS issue that is preventing the kernel or disk driver from receiving the sleep event from the drive. Is smartd running? Is smart enabled in the BIOS? Good Luck! -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines
