Hi, From: David Arendt <[EMAIL PROTECTED]> Subject: [NILFS users] some questions Date: Sun, 04 May 2008 18:16:59 +0200 > I am very interested in nilfs2 so I have some questions ?
Sure. > 1. If I understood well, nilfs is always appending to the end (is this > true or is also other data modified, for example to update pointers ?). > What is happening if I have deleted files and cleanerd deletes the > snapshots ? If you deletes files, new directory blocks that doesn't have their entries, are just written out. When the cleanerd finds a block that is not referred to from any snapshots, it is identified as removable and will not be copied during reclamation. > Will this space be written by further write operations or > will it be lost ? Eventually the abandoned block will be overrode with a new block. (To be more exact, NILFS manages disk space with units of segments; the cleanerd reclaims segments instead of disk blocks. ) > 2. I suppose that some fragmentation will build up, is there any > defragmentation tool planned ? The former is yes. Unfortunetely, the latter, no. Though some LFSes defrags during GC, our LFS not. > 3. How robust is nilfs to device errors like bad sectors ? For example > if you have a disk image where bad sectors are replaced by zeros, will > you still be able to recover data from other sectors ? When NILFS detects an I/O error, it tries to mark the segment including the bad block erroneous. The errorneous segment will never be reused. Cheers, Ryusuke Konishi _______________________________________________ users mailing list [email protected] https://www.nilfs.org/mailman/listinfo/users
