Glad it worked for you. I suspect in your case the corruption happened way down in the tree and you could get around it by pruning the tree (rm the file) below the point of corruption. I suspect this could be due to a very localized corruption like Alpha particle problem where a bit was flipped on the platter or in the cache of the storage sub-system before destaging to disk. In our case the problem was pervasive due to the problems affecting our data path (FC).
[b]You do raise a very very valid point.[/b] It'd be nice if ZFS provided better diagnostics; namely identify where exactly in the tree it found corruption. At that point we can determine if the remedy is to contain our damage (similar to fsck discarding all suspect inodes) and continue. For example I've very high regard for the space management in the Oracle DB. When it finds a bad block(s) it prints out the address of the block and marks it corrupt. [b]It doesn't put the whole file/tablespace/table/index in 'suspect' mode like ZFS[/b]. DBA can then either drop the table/index that contains the bad block or extract data from the table minus the bad block. Oracle DB handles it very gracefully giving the user/DBA a chance to recover the known good data. For ZFS to achieve wide acceptance we [b]must[/b] have the ability to pin point the problem area and take remedial action (rm for example) not simply give up. Yes there are times when the corruption could affect a block high up in the chain making the situation hopeless, in such a case we'd have to discard and restart. ZFS now has solved one part of the problem, namely identifying bad data and doing it reliably. It provides resiliency in the form form of Raid-Z(2) and Raid-1. For it to realize its full potential it must also provide tools to discard corrupt parts (branches) of the tree and give us a chance to save the remaining data. We won't always have the luxury of rebuilding the pool and restoring in a production environment. Easier said than done, me thinks. Good night. This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
