Tag Archives: cache

cPanel DNSonly bind recursion

In case you may be running into issues with named/bind domain service on cPanel DNSonly not responding to DNS queries recursively, I have a fix for you.

In older versions of named/bind9 used by cPanel if you wanted to allow anyone (or if you wanted security you could have setup an ACL, let’s assume you want to allow all) you could simply edit the configuration file and change “recursion no;” to “recursion yes;” to allow anyone to make queries to your DNS server for those domains or records that are not kept in your local server (ie: resolve yahoo.com)
Newer versions of BIND9/named changed their past behavior and now require a more specific configuration, just add these under “options” section

options {
allow-recursion { any; };
allow-query { any; };
allow-query-cache { any; };

I found a detailed explanation on why bind/named dns server changed its behavior, on the next page  a copy of the support bulletin from July 2007:

Checking for Hard drive READ and WRITE Cache (onboard) on Solaris

To check for read and write cache for your hard drives do the following:

Giovanni@server:~# format -e
Searching for disks…done
0. c8t0d0 <DEFAULT cyl 60797 alt 2 hd 255 sec 252>
1. c8t1d0 <ATA-Hitachi HDS72202-A3EA-1.82TB>
2. c8t2d0 <ATA-Hitachi HDS72202-A28A-1.82TB>
3. c8t3d0 <ATA-Hitachi HDS72202-A3EA-1.82TB>
4. c8t4d0 <ATA-Hitachi HDS72202-A3EA-1.82TB>
5. c8t5d0 <ATA-Hitachi HDS72202-A3EA-1.82TB>
Specify disk (enter its number):

Select a drive, lets pick 5 from the list.

Specify disk (enter its number): 5
selecting c8t5d0
[disk formatted]
/dev/dsk/c8t5d0s0 is part of active ZFS pool gpool. Please see zpool(1M).
disk       – select a disk
type       – select (define) a disk type
partition  – select (define) a partition table
current    – describe the current disk
format     – format and analyze the disk
fdisk      – run the fdisk program
repair     – repair a defective sector
label      – write label to the disk
analyze    – surface analysis
defect     – defect list management
backup     – search for backup labels
verify     – read and display labels
inquiry    – show vendor, product and revision
scsi       – independent SCSI mode selects
cache      – enable, disable or query SCSI disk cache
volname    – set 8-character volume name
!<cmd>     – execute <cmd>, then return

Now let’s do the checking

Enter “cache” to enter cache menu.

write_cache – display or modify write cache settings
read_cache  – display or modify read cache settings
!<cmd>      – execute <cmd>, then return

Type: “write_cache” or “read_cache” depending on what you would like to see, lets use write:

cache> write_cache
display     – display current setting of write cache
enable      – enable write cache
disable     – disable write cache
!<cmd>      – execute <cmd>, then return
write_cache> display
Write Cache is enabled

Use the same for read_cache and to disable and enable.