FAQ Search Today's Posts Mark Forums Read
» Video Reviews

» Linux Archive

Linux-archive is a website aiming to archive linux email lists and to make them easily accessible for linux users/developers.


» Sponsor

» Partners

» Sponsor

Go Back   Linux Archive > Redhat > Device-mapper Development

 
 
LinkBack Thread Tools
 
Old 02-11-2008, 09:11 PM
"Mitura, Radoslaw"
 
Default Activate/rebuilding with broken disk

Title: Activate/rebuilding with broken disk







Hi,




I'm writing code to make data recovery (rebuild) with dmraid/device-mapper.


Assume I have created and mounted a mirror raid volume with disk A and B.


# dmsetup table


isw_dgdccjfdbi_test: 0 20971779 mirror core 2 16384 nosync 2 8:16 0 8:32 0 1 handle_errors


# dmsetup status


isw_dgdccjfdbi_test: 0 20971779 mirror 2 8:16 8:32 1281/1281 1 AA 1 core




When I remove one of disk (assume A) and make write or read from that volume I receive dmsetup status with one "AD" (with appropriate patches to kernel).



I can work with one broken disk (assume it is mirror) and device-mapper will take care of next writes/reads to be directed only to device B.



Then I add a new disk C (for example 8:48).




Some questions I have:


1. How to update device mapper table in a way where device-mapper will know that I have only disk B and C and that C is a new empty disk that should not be used at the moment?



2. If 1 is possible without interrupting system work (volume is still mounted) then is it possible to start rebuilding of disk B to C (also with mounted volume)?



3. During rebuild "dmsetup status" will show rebuild progress from 0//1281 to 1281/1281 - assume it is in the middle 500/1281



A) Does device mapper take care of writes to disk B and C together if they are directed to blocks just recovered?


B) Does device mapper take care of writes only to disk B if they are directed to blocks not recovered yet?




Regards,


Radoslaw Mitura





---------------------------------------------------------------------
Intel Technology Poland sp. z o.o.
z siedziba w Gdansku
ul. Slowackiego 173
80-298 Gdansk

Sad Rejonowy Gdansk Polnoc w Gdansku,
VII Wydzial Gospodarczy Krajowego Rejestru Sadowego,
numer KRS 101882

NIP 957-07-52-316
Kapital zakladowy 200.000 zl

This e-mail and any attachments may contain confidential material for
the sole use of the intended recipient(s). Any review or distribution
by others is strictly prohibited. If you are not the intended
recipient, please contact the sender and delete all copies.

--
dm-devel mailing list
dm-devel@redhat.com
https://www.redhat.com/mailman/listinfo/dm-devel
 

Thread Tools




All times are GMT. The time now is 03:48 AM.

VBulletin, Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO ©2007, Crawlability, Inc.
Copyright 2007 - 2008, www.linux-archive.org