Commits on Mar 30, 2023

1. [201911][Arista] Disable ATA NCQ for a few products …

   Why I did it
   Some products might experience an occasional IO failure in the communication between CPU and SSD.
   Based on some research it could be attributable to some device not handling ATA NCQ (Native Command Queue).
   
   This issue currently affect 4 products:
   
   DCS-7170-32C*
   DCS-7170-64C
   DCS-7060DX4-32
   DCS-7260CX3-64
   DCS-7050CX3-32S
   
   How I did it
   This change disable NCQ on the affected drive for a small set of products.
   
   How to verify it
   When the fix is applied, these 2 patterns can be found in the dmesg.
   ata[0-9]+.00: FORCE: horkage modified (noncq)
   NCQ (not used)
   
   Test results using: fio --direct=1 --rw=randrw --bs=64k --ioengine=libaio --iodepth=64 --runtime=120 --numjobs=4
   
   with NCQ (ata1.00: 61865984 sectors, multi 1: LBA48 NCQ (depth 32), AA)
   
      READ: bw=33.9MiB/s (35.6MB/s), 33.9MiB/s-33.9MiB/s (35.6MB/s-35.6MB/s), io=4073MiB (4270MB), run=120078-120078msec
     WRITE: bw=34.1MiB/s (35.8MB/s), 34.1MiB/s-34.1MiB/s (35.8MB/s-35.8MB/s), io=4100MiB (4300MB), run=120078-120078msec
   without NCQ (ata1.00: 61865984 sectors, multi 1: LBA48 NCQ (not used))
   
      READ: bw=31.7MiB/s (33.3MB/s), 31.7MiB/s-31.7MiB/s (33.3MB/s-33.3MB/s), io=3808MiB (3993MB), run=120083-120083msec
     WRITE: bw=31.9MiB/s (33.4MB/s), 31.9MiB/s-31.9MiB/s (33.4MB/s-33.4MB/s), io=3830MiB (4016MB), run=120083-120083msec
   Which release branch to backport (provide reason below if selected)

   

   Staphylo committed Mar 30, 2023
   Configuration menu

   • View commit details
   • Copy full SHA for 4831cc3
   • Browse repository at this point

   Copy the full SHA

   4831cc3 View commit details

   Browse the repository at this point in the history