Size doesn't match on 4TB drive. Too small


I have two drives. One is a 1TB MY PASSPORT drive, and the other is a 4TB ELEMENTS drive (recently bought the latter).

For some reason, I just can’t fit the data from the 1TB into an empty 4TB drive. Both are formatted as EXTFS, with the same cluster size.

At first I thought it is because the 4TB wastes more space due to cluster size or something of that sort (and having too many files), but that’s not the case. Even when I zip the 10 main directories at the root of the 1TB files into ten files in the 4TB drive, the space still doesn’t match. The files, unrolled, in their full glory, take all space on the 1TB drive, but they take at least 2.2TB on the 4TB drive (it is still zipping, hasn’t finished yet), and I expect there won’t be enough space.

Please note that I start with 3.6TB on the 4TB after formatting it, and that it is completely empty when I start the process.

This is all very strange to me, it seems like the 4TB drive doesn’t really have 4TB on it!

Here is some info:

$ df -h
Filesystem Size Used Avail Capacity iused ifree %iused Mounted on
/dev/disk4s1 931Gi 931Gi 12Mi 100% 0 0 100% /Volumes/MY PASSPORT
/dev/disk3 3.6Ti 2.2Ti 1.4Ti 61% 148909008 95216112 61% /Volumes/Elements

4 TB information:

$ sudo newfs_exfat -N /dev/disk3
Reformatting existing ExFAT volume
Partition offset : 0 sectors (0 bytes)
Volume size      : 7813969920 sectors (4000752599040 bytes)
Bytes per sector : 512
Bytes per cluster: 16384
FAT offset       : 32768 sectors (16777216 bytes)
# FAT sectors    : 1933312
Number of FATs   : 1
Cluster offset   : 1966080 sectors (1006632960 bytes)
# Clusters       : 244125120
Volume Serial #  : 5d2afd28
Bitmap start     : 2
Bitmap file size : 30515640
Upcase start     : 1865
Upcase file size : 5836
Root start       : 1866

Here is the information from the 1TB drive:

$ sudo newfs_exfat -N /dev/disk4
Partition offset : 0 sectors (0 bytes)
Volume size      : 1953458176 sectors (1000170586112 bytes)
Bytes per sector : 512
Bytes per cluster: 131072
FAT offset       : 2048 sectors (1048576 bytes)
# FAT sectors    : 61440
Number of FATs   : 1
Cluster offset   : 63488 sectors (32505856 bytes)
# Clusters       : 7630448
Volume Serial #  : 5d406cb7
Bitmap start     : 2
Bitmap file size : 953806
Upcase start     : 10
Upcase file size : 5836
Root start       : 11


Any ideas?

I would really appreciate a response. I am starting to think that WD doesn’t sell harddrives with as much space as advertised.

So how much space do you expect out of your WD 4TB hard drive?

I would be happy with 3.6 TB as df reports, but even 1TB won’t fit on it.

but from the df -h status, your 4TB already use 2.2TB and only 1.4TB left. If you add more files that are more then 1.4TB it will not fit.

The 2.2TB used appear because I took a df -h in the middle of copying files from the 1 TB dfive to the 4 TB drive, to make my point.

I start with an empty 4TB drive (Elements), and a full 1 TB drive (MY PASSPORT).

I then zip all the files in the 1TB drive (without compression) into the 4 TB drive into about 10 files (so it is not a problem with the cluster size). Yet, df -h reports, in the middle, that I am already using 2.2 TB.

I don’t expect the 4TB harddisk now to have enough space to zip the files on the 1TB drive.

If you think the drive is defected and it is still under warranty. You could return to it to get your money back or get a replacement.