Details

    • Type: Bug
    • Status: Resolved
    • Priority: Minor
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: Lustre 2.14.0
    • Labels:
      None
    • Severity:
      3
    • Rank (Obsolete):
      9223372036854775807

      Description

      On direct I/O a client gets substantial amount of grants without consuming them so that direct I/O writes face with ENOSPC long before disk space is over.
      The below example shows how dd oflag=direct fails to write 400kb to ~70mb ost.

      [root@sl75master tests]# OSTSIZE=100000 sh llmount.sh
      ...
      Updated after 6s: wanted 'procname_uid' got 'procname_uid'
      disable quota as required
      [root@sl75master tests]# lfs df -h
      UUID                       bytes        Used   Available Use% Mounted on
      lustre-MDT0000_UUID       122.4M        1.9M      109.5M   2% /mnt/lustre[MDT:0]
      lustre-OST0000_UUID        69.4M        1.2M       61.4M   2% /mnt/lustre[OST:0]
      lustre-OST0001_UUID        69.4M        1.2M       61.4M   2% /mnt/lustre[OST:1]
      
      filesystem_summary:       138.9M        2.5M      122.7M   2% /mnt/lustre
      
      [root@sl75master tests]# dd if=/dev/zero of=/mnt/lustre/file bs=4k count=100 oflag=direct
      dd: error writing ‘/mnt/lustre/file’: No space left on device
      54+0 records in
      53+0 records out
      217088 bytes (217 kB) copied, 0.138233 s, 1.6 MB/s
      [root@sl75master tests]# 
      

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              • Assignee:
                vsaveliev Vladimir Saveliev
                Reporter:
                vsaveliev Vladimir Saveliev
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                Dates

                • Created:
                  Updated:
                  Resolved: