samba & winbind

The database is winbindd_idmap.tdb

tdbtool
tdbdump
tdbbackup

find the database
smbd -b | grep LOCKDIR

solution :
 * invalid permissions on socket directory /var/lib/samba/winbindd_privileged
--> It must be (0750)

NFS Error Code: 0x80070021

1. mount NFS folder from A server to B server ,

2. In B server, use the samba service to share to client.

3. If the client met the error code "0x80070021" ,
4. In B server, please try to use "-o nolock" to mount the NFS folder

dmidecode

Valid type keywords are:
bios
system
baseboard
chassis
processor
memory
cache
connector
slot

Type Information:
0 BIOS
1 System
2 Base Board
3 Chassis
4 Processor
5 Memory Controller
6 Memory Module
7 Cache
8 Port Connector
9 System Slots
10 On Board Devices
11 OEM Strings
12 System Configuration Options
13 BIOS Language
14 Group Associations
15 System Event Log
16 Physical Memory Array
17 Memory Device
18 32-bit Memory Error
19 Memory Array Mapped Address
20 Memory Device Mapped Address
21 Built-in Pointing Device
22 Portable Battery
23 System Reset
24 Hardware Security
25 System Power Controls
26 Voltage Probe
27 Cooling Device
28 Temperature Probe
29 Electrical Current Probe
30 Out-of-band Remote Access
31 Boot Integrity Services
32 System Boot
33 64-bit Memory Error
34 Management Device
35 Management Device Component
36 Management Device Threshold Data
37 Memory Channel
38 IPMI Device
39 Power Supply
40 Additional Information
41 Onboard Device

Ubuntu - /var/log/message ?

網路找了一下.才發現.原來到了Ubuntu 11.04 後.
就已經改到 /var/log/syslog 

UEFI + Legacy PXE server

adding those two to your  dhcpd.conf

# vim /etc/dhcp/dhcpd.com

option arch code 93 = unsigned integer 16

if option arch = 00:00 {

      filename "pxelinux.0";

} else {

      filename "BOOTX64.efi";

}

Linux : ulimit

ulimit [-SHacdfltu]

選項與參數：
-H  ：hard limit ，嚴格的設定，必定不能超過這個設定的數值；
-S  ：soft limit ，警告的設定，可以超過這個設定值，但是若超過則有警告訊息。
      在設定上，通常 soft 會比 hard 小，舉例來說，soft 可設定為 80 而 hard
      設定為 100，那麼你可以使用到 90 (因為沒有超過 100)，但介於 80~100 之間時，
      系統會有警告訊息通知你！
-a  ：後面不接任何選項與參數，可列出所有的限制額度；
-c  ：當某些程式發生錯誤時，系統可能會將該程式在記憶體中的資訊寫成檔案(除錯用)，
      這種檔案就被稱為核心檔案(core file)。此為限制每個核心檔案的最大容量。
-f  ：此 shell 可以建立的最大檔案容量(一般可能設定為 2GB)單位為 Kbytes
-d  ：程序可使用的最大斷裂記憶體(segment)容量；
-l  ：可用於鎖定 (lock) 的記憶體量
-t  ：可使用的最大 CPU 時間 (單位為秒)
-u  ：單一使用者可以使用的最大程序(process)數量。

from Linux Vbird

zone_reclaim_mode

zone_reclaim_mode:

Zone_reclaim_mode allows someone to set more or less aggressive approaches to
reclaim memory when a zone runs out of memory. If it is set to zero then no
zone reclaim occurs. Allocations will be satisfied from other zones / nodes
n the system.

This is value ORed together of

1 = Zone reclaim on
2 = Zone reclaim writes dirty pages out
4 = Zone reclaim swaps pages

zone_reclaim_mode is set during bootup to 1 if it is determined that pages from remote zones will cause a measurable performance reduction. The page allocator will then reclaim easily reusable pages (those page
cache pages that are currently not used) before allocating off node pages.

It may be beneficial to switch off zone reclaim if the system is used for a file server and all of memory should be used for caching files from disk. In that case the caching effect is more important than data locality.

Allowing zone reclaim to write out pages stops processes that are writing large amounts of data from dirtying pages on other nodes. Zone reclaim will write out dirty pages if a zone fills up and so effectively throttle the process. This may decrease the performance of a single process since it cannot use all of system memory to buffer the outgoing writes anymore but it preserve the memory on other nodes so that the performance
of other processes running on other nodes will not be affected.

Allowing regular swap effectively restricts allocations to the local node unless explicitly overridden by memory policies or cpuset configurations.