39 messages in org.freebsd.freebsd-hackersRE: offtopic: low level format of IDE...| From | Sent On | Attachments |
|---|---|---|
| Julian Elischer | Jul 8, 2002 1:47 pm | |
| Matthew Dillon | Jul 8, 2002 2:08 pm | |
| John Nielsen | Jul 8, 2002 2:10 pm | |
| Luigi Rizzo | Jul 8, 2002 2:19 pm | |
| Julian Elischer | Jul 8, 2002 2:22 pm | |
| Terry Lambert | Jul 8, 2002 2:36 pm | |
| Terry Lambert | Jul 8, 2002 2:39 pm | |
| Kenneth Culver | Jul 8, 2002 2:41 pm | |
| Kent Stewart | Jul 8, 2002 2:46 pm | |
| Julian Elischer | Jul 8, 2002 2:52 pm | |
| Robert Klein | Jul 8, 2002 2:53 pm | |
| Terry Lambert | Jul 8, 2002 3:02 pm | |
| Bakul Shah | Jul 8, 2002 3:14 pm | |
| Bernd Walter | Jul 8, 2002 3:17 pm | |
| Julian Elischer | Jul 8, 2002 3:21 pm | |
| Doug Barton | Jul 8, 2002 3:36 pm | |
| Kent Stewart | Jul 8, 2002 3:44 pm | |
| Peter Wemm | Jul 8, 2002 4:36 pm | |
| Matthew Dillon | Jul 8, 2002 4:39 pm | |
| Julian Elischer | Jul 8, 2002 4:51 pm | |
| Bernd Walter | Jul 8, 2002 5:32 pm | |
| Mike Silbersack | Jul 8, 2002 5:52 pm | |
| Greg 'groggy' Lehey | Jul 8, 2002 6:02 pm | |
| Terry Lambert | Jul 8, 2002 6:39 pm | |
| Chris Knight | Jul 8, 2002 7:08 pm | |
| Terry Lambert | Jul 8, 2002 7:12 pm | |
| Terry Lambert | Jul 8, 2002 7:22 pm | |
| Kris Kirby | Jul 8, 2002 7:40 pm | |
| Peter Wemm | Jul 8, 2002 7:43 pm | |
| Terry Lambert | Jul 8, 2002 7:45 pm | |
| Chris Knight | Jul 8, 2002 8:07 pm | |
| Cy Schubert - CITS Open Systems Group | Jul 8, 2002 10:12 pm | |
| Soeren Schmidt | Jul 9, 2002 1:39 am | |
| Don Lewis | Jul 9, 2002 3:28 am | |
| David Gilbert | Jul 9, 2002 4:00 am | |
| Chuck Robey | Jul 9, 2002 5:56 pm | |
| Sergey Babkin | Jul 10, 2002 5:23 pm | |
| Terry Lambert | Jul 10, 2002 5:57 pm | |
| David Schultz | Jul 11, 2002 4:08 am |
| Subject: | RE: offtopic: low level format of IDE drive. | |
|---|---|---|
| From: | Chris Knight (chr...@aims.com.au) | |
| Date: | Jul 8, 2002 7:08:03 pm | |
| List: | org.freebsd.freebsd-hackers | |
Howdy,
-----Original Message----- From: owne...@FreeBSD.ORG [mailto:owne...@FreeBSD.ORG]On Behalf Of Mike Silbersack Sent: Tuesday, 9 July 2002 10:53 To: Peter Wemm Cc: Julian Elischer; John Nielsen; hack...@FreeBSD.ORG Subject: Re: offtopic: low level format of IDE drive.
[snip]
So, this basically means that even a journalling filesystem wouldn't be much safer... how about battery backed up controllers - would those provide protection? (I suspect not, but maybe they're more sophisticated than I thought.)
That's right - a journalled filesystem doesn't help. Nor does battery backed up controllers. If the drive has come back and told the controller that it has written the data, then the controller - battery backed up or not - will mark those sectors as written. If it's a caching controller, then the cache entries for those sectors will be returned to the free list pool. The only way a journalled filesystem would help is if during replay, it checked that all the sectors matched prior to the checkpoint; ie write out all the sectors after the last checkpoint, then check sectors prior to the last checkpoint. That way, the journalled filesystem would know that the data had been written correctly. Does anyone have a detailed list of which SCSI drives do track writes rather than sector writes?
Regards, Chris Knight Systems Administrator AIMS Independent Computer Professionals Tel: +61 3 6334 6664 Fax: +61 3 6331 7032 Mob: +61 419 528 795 Web: http://www.aims.com.au
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