From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kay Sievers Date: Fri, 27 Jan 2006 16:48:16 +0000 Subject: Re: vol_id and RAID1 members Message-Id: <20060127164816.GA5332@vrfy.org> List-Id: References: <20060124223036.GA16374@wonderland.linux.it> In-Reply-To: <20060124223036.GA16374@wonderland.linux.it> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-hotplug@vger.kernel.org On Fri, Jan 27, 2006 at 05:35:46PM +0100, Marco d'Itri wrote: > On Jan 27, Kay Sievers wrote: > > > > Yes. Indeed, vol_id gets EIO when trying to read the superblock. > > > > > > I think that in this case it should report the error and exit, because > > > as I showed if the partition really is an array member then it will > > > report wrong information which if used will cause data loss. > > > > But how can returning an error by reading the very end of the device > > be an indication for a raid device? If we can't find a raid signature, > What I meant is that failure to read the partition should be an > indication for broken devices. The "failure to read the partition" you mean is not to be able to read the last few sectors? Yeah, it's some kind of broken, but it happens and it is perfectly useable. > > we should look for a filesystem. I've seen some devices, where the > > reported size is not fully readable and they would fail with such a logic, > > which would break other things. > These devices looks broken or at best misconfigured. > In which sane and normal scenario would a partition have sectors which > return EIO when read, but be otherwise fully functional? Oh, that's hardware magic and some devices just don't report the right size and you need to do a binary search to determine the _real_ size. We just can't ignore devices which report an incorrect size or depend on the reported size to be completely correct in all cases. The real failure to look for, is why your raid member has no longer a signature at all, right? Kay ------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://sel.as-us.falkag.net/sel?cmd=lnk&kid3432&bid#0486&dat1642 _______________________________________________ Linux-hotplug-devel mailing list http://linux-hotplug.sourceforge.net Linux-hotplug-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel