Re: XATTRs in NFS?

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

 



On Oct 27, 2013, at 5:57 PM, Christoph Anton Mitterer <calestyo@xxxxxxxxxxxx> wrote:

> On Sun, 2013-10-27 at 15:15 -0400, J. Bruce Fields wrote:
>> Was this problem actually caught using checksums stored in xattrs, or
>> did the problem predate your use of xattrs?
> Phew... don't remember actually... but I think I haven't used that
> already back then and noticed it by chance when I did some diffs.
> 
> 
>>> So the idea of my integrity data is, that I really manually say "now the
>>> data is in the state where I consider it to be consistent and I want to
>>> have checksums stored and attached to the files, for exactly that
>>> state", e.g. after I have read out some images from the SD card (perhaps
>>> even twice with the cache cleared and the results diffed) and placed in
>>> my archive.
>>> Afterwards I can regularly verify the whole archive and if at some stage
>>> corruptions as the above would have happened, I can simply take the
>>> respective files from backups.
>> How long have you been using this for?
> Uhm... about 3-4 years now.
> 
>> How many problems has it caught?
> I do not keep exact statistics... but I remember a few cases where I
> found damaged backups (optimal media) which I replaced as a consequence.
> 
>> How often do you checksum or verify files, and how expensive is that?
> Not that often,... on my actual data disks,... about every 4 months...
> on my backup media (I use to keep older generations of backups as well)
> about once a year.
> 
> I've never really looked at how expensive it is,... all you need to do
> is simply reading all data + have their hashes calculated.

...and if the checksums are any good, then all you need to do to substitute a database is to realise that a good data checksum is invariant under renames.

--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux Filesystem Development]     [Linux USB Development]     [Linux Media Development]     [Video for Linux]     [Linux NILFS]     [Linux Audio Users]     [Yosemite Info]     [Linux SCSI]

  Powered by Linux