I have fairly new gluster fs of 4 nodes with 2 RAID6 bricks on each node connected to a cluster via IPoIB on QDR IB. The servers are all SL6.2, running gluster 3.3-1; the clients are running the gluster-released glusterfs-fuse-3.3.0qa42-1 & glusterfs-3.3.0qa42-1. The volume seems normal: $ gluster volume info Volume Name: gl Type: Distribute Volume ID: 21f480f7-fc5a-4fd8-a084-3964634a9332 Status: Started Number of Bricks: 8 Transport-type: tcp,rdma Bricks: Brick1: bs2:/raid1 Brick2: bs2:/raid2 Brick3: bs3:/raid1 Brick4: bs3:/raid2 Brick5: bs4:/raid1 Brick6: bs4:/raid2 Brick7: bs1:/raid1 Brick8: bs1:/raid2 Options Reconfigured: performance.cache-size: 268435456 nfs.disable: on performance.io-cache: on performance.quick-read: on performance.io-thread-count: 64 auth.allow: 10.2.*.*,10.1.*.* The logs on both the server and client are remarkable in their lack of anything amiss (the server has the previously reported zillion times repeating string of: I [socket.c:1798:socket_event_handler] 0-transport: disconnecting now which seems to be correlated with turning the NFS server off. This has been mentioned before. The gluster volume log, stripped of that line is here: <http://pastie.org/4309225> Individual large-file reads and writes are in the >300MB/s range which is not magnificent but tolerable. However, we've recently detected what appears to be a conflict in reading and writing for some applications. When some applications are reading and writing to the gluster fs, the client /usr/sbin/glusterfs increases its CPU consunmption to >100% and the IO goes to almost zero. When the inputs are on the gluster fs and the output is on another fs, performance is as good as on a local RAID. This seems to be specific to a particular application (bedtools, perhaps some other openmp genomics apps - still checking). Other utilities (cp, perl, tar, and other utilities ) that read and write to the gluster filesystem seem to be able to push and pull fairly large amount of data to/from it. The client is running a genomics utility (bedtools) which reads a very large chunks of data from the gluster fs, then aligns it to a reference genome. Stracing the run yields this stanza, after which it hangs until I kill it. The user has said that it does complete but at a speed hundreds of times slower (maybe timing out at each step..?) open("/data/users/tdlong/bin/genomeCoverageBed", O_RDONLY) = 3 ioctl(3, SNDCTL_TMR_TIMEBASE or TCGETS, 0x7fffcf0e5bb0) = -1 ENOTTY (Inappropriate ioctl for device) lseek(3, 0, SEEK_CUR) = 0 read(3, "#!/bin/sh\n${0%/*}/bedtools genom"..., 80) = 42 lseek(3, 0, SEEK_SET) = 0 getrlimit(RLIMIT_NOFILE, {rlim_cur=4*1024, rlim_max=4*1024}) = 0 dup2(3, 255) = 255 close(3) = 0 fcntl(255, F_SETFD, FD_CLOEXEC) = 0 fcntl(255, F_GETFL) = 0x8000 (flags O_RDONLY|O_LARGEFILE) fstat(255, {st_mode=S_IFREG|0755, st_size=42, ...}) = 0 lseek(255, 0, SEEK_CUR) = 0 rt_sigprocmask(SIG_BLOCK, NULL, [], 8) = 0 read(255, "#!/bin/sh\n${0%/*}/bedtools genom"..., 42) = 42 rt_sigprocmask(SIG_BLOCK, NULL, [], 8) = 0 rt_sigprocmask(SIG_BLOCK, [INT CHLD], [], 8) = 0 clone(child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x2ae9318729e0) = 8229 rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0 rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0 rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0 rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0 rt_sigaction(SIGINT, {0x436f40, [], SA_RESTORER, 0x3cb64302d0}, {SIG_DFL, [], SA_RESTORER, 0x3cb64302d0}, 8) = 0 wait4(-1, Does this indicate any optional tuning or operational parameters that we should be using? hjm -- Harry Mangalam - Research Computing, OIT, Rm 225 MSTB, UC Irvine [m/c 2225] / 92697 Google Voice Multiplexer: (949) 478-4487 415 South Circle View Dr, Irvine, CA, 92697 [shipping] MSTB Lat/Long: (33.642025,-117.844414) (paste into Google Maps)