On Wed, Sep 5, 2012 at 2:32 PM, Kevin Liao <kevinlia@xxxxxxxxx> wrote: > 2012/9/4 Theodore Ts'o <tytso@xxxxxxx>: >> On Tue, Sep 04, 2012 at 09:59:55AM +0800, Yongqiang Yang wrote: >>> Hi Kevin, >>> >>> Ted has sent out the patches on online resizing for meta_bg and >>> 64bits, so you can have a try again. It seems that the bug in >>> e2fsprogs has been fixed. >> >> Make sure you use the latest version of the kernel patches that I just >> sent out. There quite a number of bugs in the Yongqiang's original >> patch set which I tripped over while I was testing 64-bit resize --- >> and please note that there are definitely still rough edges >> (especially for in cases where the file system was created < 16TB, but >> with the 64-bit feature and resize_inode features enabled). There may >> also be bugs for the straightforward case of resizing very large file >> systems. >> >> So while I very much appreciate users giving the code a try and >> sending us feedback, please do think twice before using this code on >> file systems with data that hasn't been backed up recently. (Of >> course, being good System Administrators you are all keeping --- and >> verifying --- regular backups, right? :-) >> >> Regards, >> >> - Ted > > I had done some simple and quick test. The following is the result. > > Kernel: 3.4.7 + 5 patches > e2fsprogs: 1.42.5 + 2 patches > > The format command I used is: > mke2fs -t ext4 -m0 -b 4096 -F -O 64bit,meta_bg,^resize_inode /dev/md0 nnnn > > Case 1: Simplly resize > 1st step: resize from 14T to 18T => ok > 2nd step: resize from 18T to 20T => ok (calculate_minimum_resize_size > issue gone) > 3rd step: resize from 20T to 21T => ok > > Case 2: case 1 + file read-write (just like Anssi did) > 1st step: resize from 14T to 20T (5368709120 blocks) => ok > 2nd step: resize from 20T to 5368709170 blocks => same kernel bug_on > > Case 3: case 2 + Yongqiang's 2 patches > 1st step: resize from 14T to 20T (5368709120 blocks) => ok > 2nd step: resize from 20T to 5368709170 blocks => ok > > Basically I think the resize funtionality should be ok. However I also > observe some performance drop. That is, the time needed for mke2fs, > mount and e2fsck are longer than before. Here is some detailed data: > > For 12TB with 64bit,meta_bg,^resize_inode > mke2fs: 54.699s > mount: 12.108s > e2fsck: 1m52.027s > > For 12TB without 64bit,meta_bg,^resize_inode Did you mean without 64bit and without meta_bg OR with without 64bit and with meta_bg? I am guessing you meant without 64bit and without meta_bg, am I right? Yongqiang. > mke2fs: 39.763s > mount: 0.897s > e2fsck: 1m17.554s > > For 20TB with 64bit,meta_bg,^resize_inode > mke2fs: 1m25.090s > mount: 19.992s > e2fsck: 2m55.048s > > For 20TB without 64bit,meta_bg,^resize_inode > mke2fs: 1m3.660s > mount: 1.458s > e2fsck: 1m56.055s > > Yongqiang had told me previously that it may be caused by using > meta_bg. I am still wondering is there anything we can do to improve > the peroformance? Thanks a lot. > > Regards, > Kevin Liao -- Best Wishes Yongqiang Yang -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
