While it is true that e2fsck does not free memory during operation, in practice this is not a problem. Even for large filesystems (say 32-48TB) it will only use around 8-12GB of RAM so that is very reasonable for a server today. The rough estimate that I use for e2fsck is 1 byte of RAM per block. Cheers, Andreas > On Mar 21, 2017, at 16:07, Manish Katiyar <mkatiyar@xxxxxxxxx> wrote: > > Hi, > > I was looking at e2fsck code to see if there are any limits on running > e2fsck on large ext4 filesystems. From the code it looks like all the > required metadata while e2fsck is running is only kept in memory and > is only flushed to disk when the appropriate changes are corrected. > (Except the undo file case). > There doesn't seem to be a case/code where we have to periodically > flush some tracking metadata while it is running, just because we have > too much of incore tracking data and may ran out of memory (looks like > code will simply return failure if ext2fs_get_mem() returns failure) > > Appreciate if someone can confirm that my understanding is correct ? > > Thanks - > Manish
