-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Ivan Voras wrote: > Thomas Backman wrote: >> I'm copying this over from the freebsd-performance list, as I'm >> looking for a few more opinions - not on the problems *I* am having, >> but rather to check whether the problem is universal or not, and if >> not, find a possible common factor. >> In other words: I want to hear about your experiences, *good or bad*! >> >> Here's the original thread (not from the beginning, though): >> http://lists.freebsd.org/pipermail/freebsd-performance/2009-October/003843.html >> >> >> Long story short, my version: when the disk is stressed hard enough, >> console IO becomes COMPLETELY unbearable. 10+ seconds to switch >> between windows in screen(1), running (or even typing) simple >> commands, etc. This happens both via SSH and the serial console. > > Hmm, this looks familiar - I've noticed it before on the physical (VGA) > console and I notice it all the time under VMWare. It sort of looks like > disk IO really blocks network IO in this case - I use the VMs over ssh.
I've seen some similar behaviour here with my zfs/istgt backend. I "resolved" the issue by reducing the arc_max so that each disk-io cycle would be "short enough" not to cause the istgt to generate timeouts towards my two vmware hosts. The io-backend for the box is a megaraid 8308 (mfi) card with 8 disks on it. This box is running RELENG_7 now (I tried running it with RELENG_8 but it had a nasty tendency of simply locking up, dragging down both my ESXi hosts with it). //Svein - -- - --------+-------------------+------------------------------- /"\ |Svein Skogen | sv...@d80.iso100.no \ / |Solberg Østli 9 | PGP Key: 0xE5E76831 X |2020 Skedsmokorset | sv...@jernhuset.no / \ |Norway | PGP Key: 0xCE96CE13 | | sv...@stillbilde.net ascii | | PGP Key: 0x58CD33B6 ribbon |System Admin | svein-listm...@stillbilde.net Campaign|stillbilde.net | PGP Key: 0x22D494A4 +-------------------+------------------------------- |msn messenger: | Mobile Phone: +47 907 03 575 |sv...@jernhuset.no | RIPE handle: SS16503-RIPE - --------+-------------------+------------------------------- If you really are in a hurry, mail me at svein-mob...@stillbilde.net This mailbox goes directly to my cellphone and is checked even when I'm not in front of my computer. - ------------------------------------------------------------ Picture Gallery: https://gallery.stillbilde.net/v/svein/ - ------------------------------------------------------------ -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkrUdB4ACgkQODUnwSLUlKQjtwCcDWA7BqDdwQ6w8zo0shNJDpJW shkAoKK1hN5QVrmg59J4lGV3V45ooiPj =nUay -----END PGP SIGNATURE----- _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"