Size vs Size on Disk

[reggierat]

I've been running Emby and just noticed it's config folder is massive 100GB + and chewing up most of my 250gb SSD.

 

Looking at the People folder you will see the discrepancy between actual size and size on disk.  I understand this is caused by block size on the drive.  My Cache drive is formatted as XFS with 512byte sector size (i think)  I'm wondering what would be a better setting for this to make the most of the storage on the disk.

[reggierat]

SSD information attached

[garycase]

While size vs. size on disk is generally a reflection of the slack space in the allocation units [on average, this will be statistically be 1/2 the allocation unit size], the difference you're seeing is far greater than this could account for.

 

While the sectors on your disk are 512 bytes, the more important factor is the allocation unit, or "block" size ... this is the amount of space in each allocated unit for a file.    The default for XFS is 4KB ... I don't know what UnRAID sets this to when disks are formatted, but if it's 4k, the worst possible amount of slack space you could have in a file would be (4k-1) bytes (i.e. 4095 bytes/file) => which, for 53,227 files, would be a total of 218MB of "wasted" space -- i.e. less than 1/4 of a GB.    So clearly this can't account for the 50.84GB difference between size and size-on-disk that you're seeing.

 

What size does this set of files use on a disk if you copy the entire folder to a Windows client ?

 

[Squid]

Windows also isn't perfect for calculating size on disk either for networked devices.

 

For example, if I happen to have windows give me the stats on my appdata folder, it actually keeps growing and growing until windows reports that the size on disk is actually greater than my cache drive.