-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Tomasz Chmielewski wrote: > Is it possible to "freeze I/O" for some time to a given disk / md / dm > device? > > Say, "freeze I/O" so that userspace waits for any response for 30, 60 > seconds or more? You can suspend/resume dm devices via the dmsetup command. > If not, is it possible to reset a link repeatedly, like ATA does when it > hits certain disk problems? I.e., can I do the below manually? > > ata4.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x2 frozen > ata4.00: cmd 25/00:08:b8:c2:78/00:00:21:00:00/e0 tag 0 dma 4096 in > res 40/00:00:bb:c2:78/40:00:21:00:00/e0 Emask 0x4 (timeout) > ata4.00: status: { DRDY } > ata4: hard resetting link This (or something close to it) should be possible using the SCSI fault injection framework, a project that uses systemtap for injecting faults under controlled conditions: http://sourceforge.net/projects/scsifaultinjtst/ http://lwn.net/Articles/265187/ http://lwn.net/Articles/289932/ Regards, Bryn. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org iEYEARECAAYFAklHoJgACgkQ6YSQoMYUY94xEwCeOJ/epr+4QipelzzeH22M52az 53MAoLOZTNPlwq6t1PyLgNA/Ous64++z =apWm -----END PGP SIGNATURE----- _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/