1 |
On 27/07/2014 17:55, J. Roeleveld wrote: |
2 |
> On 27 July 2014 18:25:24 CEST, "Stefan G. Weichinger" <lists@×××××.at> wrote: |
3 |
>> Am 26.07.2014 04:47, schrieb walt: |
4 |
>> |
5 |
>>> So, why did the "broken" machine work normally for more than a year |
6 |
>>> without rpcbind until two days ago? (I suppose because nfs-utils was |
7 |
>>> updated to 1.3.0 ?) |
8 |
>>> |
9 |
>>> The real problem here is that I have no idea how NFS works, and each |
10 |
>>> new version is more complicated because the devs are solving problems |
11 |
>>> that I don't understand or even know about. |
12 |
>> |
13 |
>> I double your search for understanding ... my various efforts to set up |
14 |
>> NFSv4 for sharing stuff in my LAN also lead to unstable behavior and |
15 |
>> frustration. |
16 |
>> |
17 |
>> Only last week I re-attacked this topic as I start using puppet here to |
18 |
>> manage my systems ... and one part of this might be sharing |
19 |
>> /usr/portage |
20 |
>> via NFSv4. One client host mounts it without a problem, the thinkpads |
21 |
>> don't do so ... just another example ;-) |
22 |
>> |
23 |
>> Additional in my context: using systemd ... so there are other |
24 |
>> (different?) dependencies at work and services started. |
25 |
>> |
26 |
>> I'd be happy to get that working in a reliable way. I don't remember |
27 |
>> unstable behavior with NFS (v2 back then?) when we used it at a company |
28 |
>> I worked for in the 90s. |
29 |
>> |
30 |
>> Stefan |
31 |
> |
32 |
> I use NFS for filesharing between all wired systems at home. |
33 |
> Samba is only used for MS Windows and laptops. |
34 |
> |
35 |
> Few things I always make sure are valid: |
36 |
> - One partition per NFS share |
37 |
> - No NFS share is mounted below another one |
38 |
> - I set the version to 3 on the clients |
39 |
> - I use LDAP for the user accounts to ensure the UIDs and GIDs are consistent. |
40 |
|
41 |
These are generally good recommendations. I'd just like to make a few |
42 |
observations. |
43 |
|
44 |
The problems associated with not observing the first constraint (one |
45 |
filesystem per export) can be alleviated by setting an explicit fsid. |
46 |
Doing so can also help to avoid stale handles on the client side if the |
47 |
backing filesystem changes - something that is very useful in a |
48 |
production environment. Therefore, I tend to start at 1 and increment |
49 |
with each newly added export. For example:- |
50 |
|
51 |
/export/foo *(async,no_subtree_check,fsid=1) |
52 |
/export/foo/bar *(async,no_subtree_check,fsid=2) |
53 |
/export/baz *(async,no_subtree_check,fsid=3) |
54 |
|
55 |
If using NFSv3, I'd recommend using "nolock" as a mount option unless |
56 |
there is a genuine requirement for locks to be co-ordinated. Such locks |
57 |
are only advisory and are of questionable value. Using nolock simplifies |
58 |
the requirements on both server and client side, and is beneficial for |
59 |
performance. |
60 |
|
61 |
NFSv3/UDP seems to be limited to a maximum read/write block size of |
62 |
32768 in Linux, which will be negotiated by default. Using TCP, the |
63 |
upper bound will be the value of /proc/fs/nfsd/max_block_size on the |
64 |
server. Its value may be set to 1048576 at the most. NFSv3/TCP is |
65 |
problematic so I would recommend NFSv4 if TCP is desired as a transport |
66 |
protocol. |
67 |
|
68 |
NFSv4 provides a useful uid/gid mapping feature that is easier to set up |
69 |
and maintain than nss_ldap. |
70 |
|
71 |
> |
72 |
> NFS4 requires all the exports to be under a single foldertree. |
73 |
|
74 |
This is a myth: |
75 |
http://linuxcostablanca.blogspot.co.uk/2012/02/nfsv4-myths-and-legends.html. |
76 |
Exports can be defined and consumed in the same manner as with NFSv3. |
77 |
|
78 |
> |
79 |
> I haven't had any issues in the past 7+ years with this and in the past 5+ years I had portage, distfiles and packages shared. |
80 |
> /etc/portage is symlinked to a NFS share as well, allowing me to create binary packages on a single host (inside a chroot) which are then used to update the different machines. |
81 |
> |
82 |
> If anyone wants a more detailed description of my setup. Let me know and I will try to write something up. |
83 |
> |
84 |
> Kind regards |
85 |
> |
86 |
> Joost |
87 |
> |
88 |
|
89 |
--Kerin |