On Thu, Feb 14, 2013 at 3:36 PM, Mitchell Laks <ml...@post.harvard.edu> wrote: > On 20:34 Thu 14 Feb, emmanuel segura wrote: >> >> man tune2fs >> >> -r reserved-blocks-count >> Set the number of reserved filesystem blocks. >> >> be careful with filesystem reserved block, one time i had a production >> server with / corrupted > > I have a very specific use here. > > I am using this partition only for 1 time backup of static data, on a backup > machine. > > I am confused. > > I had set the reseved block count to 0 with the > tune2fs -m0 option. > > This is because I dont use this device for system or root. Just data > storage. > > However I see on the system currently (after only doing tune2fs -m0) > > 1. File system features of resize_inode > 2. Reserved block count 0 > 3. Reserved GDT blocks 1002 > > what is the idea here of tune2fs -r? > It says currently that reserved block count is 0. > > Should I want to get rid f the GDT blocks? > Are they the only culprit remaining? > Are they only used for resizing? > I will not need to resize once I do my full data backup to this partition. > > I am confused because I don't understand the -r option vs the -m 0 option. > > According to the following comment from Theodore Tso author of ext2/3/4 > > http://www.redhat.com/archives/ext3-users/2006-May/msg00008.html > > " >> 1) what does the "Reserved GDT blocks" mean? and what >> are its functions and purposes? > > It means that blocks have been reserved in order to allow on-line > resizing. The filesystem will also have "resize_inode" in the > filesystem features line reported by dumpe2fs. This is most useful if > the filesystem has been created on a Logical Volume managed by an LVM > system so that when the LV is expanded, the filesystem can take > advantage of the new disk space without needing to unmount the > filesystem first. > > Filesystems that don't have this set can of course still be resized > off-line using resize2fs. > " > > I want to understand. Does the -r option turn off the reside_inode reserved > space?? what number to put after -r? > Is that what I want to do? > Are there any good online references to the next step to get back space, if > it is safe to do?
The "-m" option of mkfs.ext3 and the "-r" option of tune2fs are the same and they're used to set aside space for root and root-owned processes. GDT blocks are used for online resizing but as Tso says you can resize offline without them. You can use "-O ^resize_inode" to unset this option. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/CAOdo=SyuMRzYgGJ-OZonOXbY8+v2pijzUmf4morMfygufM=z...@mail.gmail.com
