On June 17, 2014 11:29:17 AM EDT, Matthias Schniedermeyer <ms@xxxxxxx> wrote: >On 17.06.2014 22:37, Dave Chinner wrote: >> On Tue, Jun 17, 2014 at 10:26:51AM +0200, Matthias Schniedermeyer >wrote: >> > Hi >> > >> > How seriously meant is "V5 isn't experimental anymore"? >> >> "Fully supported" isn't a clear enough statement? > >I guess that was a "selective memory"-bug on my side. > >> > I ask because the man-page only mentions the syntax to enable it by > >> > accident. A.k.a. the backport of ftype to V4. >> > (man-page of xfsprogs 3.2.0 in Debian-SID) >> >> That's intentional. V5 superblocks are an implementation detail that >> most users don't even need to know about. They care about the name >> of the features they are enabling at mkfs time, not the details of >> the on-disk implementation of those features. > >The question still stands. > >The crc-option is only mentioned "by accident". >Without the ftype backport there would be no mention of the "feature >crc". > >Furthermore i suspect that the ftype-feature also wouldn't be >mentionted >without the V4 backport. > >Which beggs the question, what other features are "burried" in V5 that >aren't mentioned in the man-page. > >And are there any other "-m" options, because "-m" (asside from the >ftype accident) is completly undocumented. > >> > And you still have to know that crc means V5. >> >> Why do you care about the format mkfs.xfs chooses for you - it's >> based on the features you requested. V5 isn't magically faster than > >I find the crc feature relativly important. > >I personally had exprienced an USB enclosure(-model. As in i had >several >of those) that under rare circumstances flipped or cleared a single bit > >in a specific bit-pattern). Such corruption most likely ends up inside >a >data-file because most times there is more data than meta-data. But >COULD happend inside the meta-data. > >Since that day i have nearly everything MD5(or SHA256)ed so i can at >least detect if i have a data-corruption. > >Fortunatly that never happend again after i replaced that enclosure >model. Which i can say with pretty high confidence. I md5 hash a lot of important files. I've seen lots of failures to verify over the years. As you note, it is typically a hardware failure, but they happen none the less. Recently the most common failure has been the sata cables. They are not very robust if you connect/disconnect them very often. Greg -- Sent from my Android phone with K-9 Mail. Please excuse my brevity. _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
