[LU-9176] ZFS MDT sizing. 7TB of MDT shows LFS support for 215M files?

• Type: Bug
• Resolution: Fixed
• Priority: Major
• Fix Version/s: Lustre 2.10.0
• Affects Version/s: Lustre 2.7.0, Lustre 2.8.0, Lustre 2.9.0
• Environment: CentOS 7.3, EE 3.1.0.3, ZFS 0.6.5.7
• Severity: 3
• Assignee: Joseph Gmitter (Inactive)
• Reporter: Jeff Johnson (Inactive)

Description

LFS configuration with two DNE2 MDTs, one MDT per MDS pair. LFS shows support for 215M files.

MDT0000: 3.3TB zpool
MDT0001: 3.7TB zpool

1. lfs df
   UUID 1K-blocks Used Available Use% Mounted on
   data-0-MDT0000_UUID 3374354432 9472 3374342912 0% /mnt/data-0[MDT:0]
   data-0-MDT0001_UUID 3749283200 9344 3749271808 0% /mnt/data-0[MDT:1]

1. lfs df -i
   UUID Inodes IUsed IFree IUse% Mounted on
   data-0-MDT0000_UUID 102359233 259 102358974 0% /mnt/data-0[MDT:0]
   data-0-MDT0001_UUID 113503655 248 113503407 0% /mnt/data-0[MDT:1]

A single 3.3TB MDT should result in ~800M files. A 3.3TB and 3.7TB MDT I should be seeing a lot more than 215M files.

What am I missing?