Red Hat Bugzilla – Bug 682831
Bad ext4 sync performance on 16 TB GPT partition
Last modified: 2016-04-18 01:55:56 EDT
This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux maintenance release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Update release for currently deployed products. This request is not yet committed for inclusion in an Update release.
Patch(es) available on kernel-2.6.32-128.el6
The difference is not so big, but it does improve the sync performance from my testing. Set it to VERIFIED On -71 kernel [root@ibm-x3550m3-02 scratch]# /usr/bin/time bash -c "dd if=/dev/zero of=bigfile bs=1M count=10000 && sync" 10000+0 records in 10000+0 records out 10485760000 bytes (10 GB) copied, 90.0757 s, 116 MB/s 0.00user 22.23system 1:31.04elapsed 24%CPU (0avgtext+0avgdata 7312maxresident)k 744inputs+286130176outputs (1major+1053minor)pagefaults 0swaps On -128 kernel [root@ibm-x3550m3-02 scratch]# /usr/bin/time bash -c "dd if=/dev/zero of=bigfile bs=1M count=10000 && sync" 10000+0 records in 10000+0 records out 10485760000 bytes (10 GB) copied, 64.9366 s, 161 MB/s 0.00user 9.14system 1:24.04elapsed 10%CPU (0avgtext+0avgdata 7296maxresident)k 56inputs+20480000outputs (1major+1055minor)pagefaults 0swaps Multiple runs always showed about 5 seconds improvement. The testing environment is a ibm-x3550 host with 16G memory and 16 cores, on a 200G ext4 partition. [root@ibm-x3550m3-02 ~]# free -m total used free shared buffers cached Mem: 15940 441 15498 0 0 10 -/+ buffers/cache: 430 15509 Swap: 0 0 0 [root@ibm-x3550m3-02 ~]# grep -c proc /proc/cpuinfo 16 [root@ibm-x3550m3-02 scratch]# mount | grep scratch /dev/mapper/vg_ibmx3550m302-test on /mnt/scratch type ext4 (rw)
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2011-0542.html