Hi, I have an I/O load issue and after days of searching wanted to know if anyone has pointers on how to approach this.
My 1-year stable zfs system (raidz3 8 2TB drives, all OK) just started to cause problems when I introduced a new backup script that puts medium I/O load. This script simply tars up a few filesystems and md5sums the tarball, to copy to another system for off OpenSolaris backup. The simple commands are: tar -c /tank/[filesystem]/.zfs/snapshot/[snapshot] > /tank/[otherfilesystem]/file.tar md5sum -b /tank/[otherfilesystem]/file.tar > file.md5sum These 2 commands obviously cause high read/write I/O because the 8 drives are directly reading and writing a large amount of data as fast as the system can go. This is OK and OpenSolaris functions fine. The problem is I host VMWare images on another PC which access their images on this zfs box over smb, and during this high I/O period, these VMWare guests are crashing. What I think is happening is during the backup with high I/O, zfs is delaying reads/writes to the VMWare images. This is quickly causing VMWare to freeze the guest machines. When the backup script is not running, the VMWare guests are fine, and have been fine for 1-year. (setup has been rock solid....) Any idea how to address this? I'd thought puting the relevant filesystem (tank/vmware) on a higher priority for reads/writes, but haven't figured out how. Another way is to deprioritize the backup somehow. Any pointers would be appreciated. Thanks, Tom -- This message posted from opensolaris.org _______________________________________________ opensolaris-help mailing list opensolaris-help@opensolaris.org
