Hello, I need to create large files fast without initializing them - in the past I used these steps - mkfs -t xfs -f -d unwritten=0 /dev/sda1 mount -t xfs -o noatime /dev/sda1 /hay touch /hay/foo xfs
Is there a reason that you don't want the unwritten flag set? (You know that not using the unwritten extents feature exposes garbage from the disk in this case?) There may well be a legit reason but
I want to avoid any metadata modifications while doing O_DIRECT reads (the fs is mounted with noatime). Right now I am doing it mostly for testing - I am seeing a performance degradation going from r
you may want to try the inode64 mount option so the allocator is free to roam your whole 10T ... Ok, so it sounds like you do understand the implications and you want to be able to write into preallo
doesn't seem to work - I tried to clear the extflg in the versionnum of the superblock (in every copy of it as well) but it doesn't work. The flag is still set on all extents. versionnum [0xb4a4+0x8]
Oh, you'd probably need to do this when there are no files already with the flag, i.e. on a fresh fs I think. all options for mkfs should be doc'd in the mkfs.xfs manpage inode64 is also doc'd in my
Sure - that xfs_db command only clears it from the superblock so that *new* preallocations don't have the unwritten bit set. it doesn't change existing allocations. More likely is that repair is seei
I did it on a fresh filesystem (of course). It didn't make a difference - sb flags cleared, extent flags set, xfs_repair unhappy. I tried to repro again and do cut/paste of my steps but I lost the ma
...... Uninitialised extents beyond EOF get zeroed when EOF is moved. if you set the set before preallocation, then there are no extents to zero. FWIW, if they have the unwritten flag, this zeroing d