[Gluster-users] Quantum directories?

[Diego Zuccato]

Hello all.

I just noticed a really inexplicable (for me) behaviour:

root at str957-cluster:/scratch/.resv2# mkdir test
root at str957-cluster:/scratch/.resv2# ls -la
total 4
drwxr-xr-x 16 root root 4096 Apr 22 11:40 ..
root at str957-cluster:/scratch/.resv2# mkdir test
mkdir: cannot create directory 'test': File exists
root at str957-cluster:/scratch/.resv2# ls -la
total 4
drwxr-xr-x 16 root root 4096 Apr 22 11:40 ..
root at str957-cluster:/scratch/.resv2# cd test
root at str957-cluster:/scratch/.resv2/test# pwd
/scratch/.resv2/test

The directory both exists and doesn't exist at the same time???

The volume is:
Volume Name: cluster_data
Type: Distributed-Replicate
Volume ID: a8caaa90-d161-45bb-a68c-278263a8531a
Status: Started
Snapshot Count: 0
Number of Bricks: 21 x (2 + 1) = 63
Transport-type: tcp
Bricks:
Brick1: clustor00:/srv/bricks/00/d
Brick2: clustor01:/srv/bricks/00/d
Brick3: clustor02:/srv/quorum/00/d (arbiter)
[...snip...]
Brick61: clustor01:/srv/bricks/13/d
Brick62: clustor02:/srv/bricks/13/d
Brick63: clustor00:/srv/quorum/06/d (arbiter)
Options Reconfigured:
features.scrub: Active
features.bitrot: on
cluster.lookup-optimize: on
performance.stat-prefetch: on
performance.cache-refresh-timeout: 60
client.event-threads: 8
performance.client-io-threads: on
nfs.disable: on
transport.address-family: inet
features.quota: on
features.inode-quota: on
features.quota-deem-statfs: on
features.default-soft-limit: 90
cluster.self-heal-daemon: enable
performance.write-behind-window-size: 128MB
performance.parallel-readdir: on

Disabling performance.parallel-readdir seems to "fix" it, but IIUC it
shouldn't happen even with parallel-readdir turned on, right?

PS: sometimes, access to the volume becomes quite slow (3-4s for a ls of
a dozen files). Any hints about options I could enable or change? The 3
servers currently have only 96GB RAM (already asked to double it), and
should host up to 36 bricks + 18 quorums). There are about 50 clients.

Tks.

-- 
Diego Zuccato
DIFA - Dip. di Fisica e Astronomia
Servizi Informatici
Alma Mater Studiorum - Università di Bologna
V.le Berti-Pichat 6/2 - 40127 Bologna - Italy
tel.: +39 051 20 95786