Description of problem:
root@Dagobah:/data/mounts/mount# /opt/qa/tools/fileop -f 30 -t 

Fileop:  Working in ., File size is 1,  Output is in Ops/sec. (A=Avg, B=Best, W=Worst)
Mkdir failed

fileop failed because, when replace-brick is happening, the quota thinks that the limit has been exceeded as it says in the log file.

client log where fileop failed:
[2012-03-26 12:35:38.027440] W [client3_1-fops.c:1589:client3_1_entrylk_cbk] 0-vol-client-3: remote operation failed: No such file or directory
[2012-03-26 12:35:38.031252] W [client3_1-fops.c:1589:client3_1_entrylk_cbk] 0-vol-client-3: remote operation failed: No such file or directory
[2012-03-26 12:35:38.035945] W [client3_1-fops.c:1489:client3_1_inodelk_cbk] 0-vol-client-3: remote operation failed: No such file or directory
[2012-03-26 12:35:38.039417] W [client3_1-fops.c:1489:client3_1_inodelk_cbk] 0-vol-client-3: remote operation failed: No such file or directory
[2012-03-26 12:36:17.572514] W [fuse-bridge.c:272:fuse_entry_cbk] 0-glusterfs-fuse: 8807: MKDIR() /fileop_L1_3/fileop_L1_3_L2_3/fileop_dir_3_3_18 => -1 (Disk quota exceeded)

Both the clients are connected to the same volume, & the volume is a 2x2 distributed-replicate volume.

df -h output:
dagobah:vol           7.0G  262M  6.8G   4% /data/mounts/fuse
dagobah:vol           7.0G  -75G   82G   -  /data/mounts/mount