Re: can I freeze I/O for some time to a given disk / md / dm device?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



-----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/

[Index of Archives]     [Gluster Users]     [Kernel Development]     [Linux Clusters]     [Device Mapper]     [Security]     [Bugtraq]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]

  Powered by Linux