PDA

View Full Version : release of memory



brandons
November 22nd, 2007, 12:47 AM
Hi,

I have a memory usage problem on the clients where a backup will use all the free memory available to perform the backup, but then fails to release that memory after the backup process is completed. I thought it was the version i was using 3 Years old. I have since upgraded to latest client & backup, with the same results.

OS-RH AS4 With all RHN updates
amanda-backup_server-2.5.2p1-1
amanda-backup_client-2.5.2p1-1

Limited text on this issue. Can someone help please??

Brandon

paddy
November 22nd, 2007, 08:45 PM
Hi,

I have a memory usage problem on the clients where a backup will use all the free memory available to perform the backup, but then fails to release that memory after the backup process is completed. I thought it was the version i was using 3 Years old. I have since upgraded to latest client & backup, with the same results.

OS-RH AS4 With all RHN updates
amanda-backup_server-2.5.2p1-1
amanda-backup_client-2.5.2p1-1

Limited text on this issue. Can someone help please??

Brandon

Please provide more information. What is the amount of memory (physical + swap) available on the client?

Please post the dle entries for the client. Information from client logs will
be also useful. How big are the DLE filesystems?

One suggestion - Take a look at the spindle parameter in the disklist configuration file. http://wiki.zmanda.com/index.php/Amanda#DISKLIST_FILE or man amanda.

Paddy

brandons
November 22nd, 2007, 11:34 PM
Hi Paddy,

Thanks for trying to help out.

I have attached the info you asked for.

I will have a look at the link you gave.

thax

Brandon

brandons
November 23rd, 2007, 06:27 AM
paddy,

I set the spindle to 1

server.domain.com /ServerScripts comp-queue-tar 1
server.domain.com /usr/local comp-queue-tar 1
server.domain.com /etc comp-queue-tar 1
server.domain.com /opt comp-queue-tar 1
server.domain.com /var comp-queue-tar 1

Same effect the mem usage few upduring the backup and has stayied up after, does not come down.

Note: that this is purely an amanda client the amanda server is on another server altogether.

All clients experience the same syntomums except for the backup server.

martineau
November 23rd, 2007, 06:40 AM
There is no problem, it's normal on linux to have a lot of memory in buffers/cached
It also say that there is 876412 free memory in buffers/cache.
This memory will be available when you need it.

It's normal for amanda to use a lot of cache, but it's not a problem.
Thanks to linux for it's cache, it really help.

brandons
November 23rd, 2007, 12:47 PM
Hi martineau,

Thanks for this, but if what you say is true why doesn't the mem in use drop after the backup completes such as in my client when i do a free?

free
total used free shared buffers cached
Mem: 1034604 1000332 34272 0 167100 675040
-/+ buffers/cache: 158192 876412
Swap: 2031608 192 2031416

Brandon

martineau
November 23rd, 2007, 12:55 PM
The memory of a process is freed, but not the cache because it can be needed.
The cache will be freed only if you request memory.
read linux documentation, i'm not qualified to explain it.

paddy
November 23rd, 2007, 05:35 PM
Hi martineau,

Thanks for this, but if what you say is true why doesn't the mem in use drop after the backup completes such as in my client when i do a free?

free
total used free shared buffers cached
Mem: 1034604 1000332 34272 0 167100 675040
-/+ buffers/cache: 158192 876412
Swap: 2031608 192 2031416

Brandon

Please see http://sourcefrog.net/weblog/software/linux-kernel/free-mem.html
for an explanation.

Paddy

brandons
November 24th, 2007, 07:23 AM
Many Thanks to both of you for your quick and helpful responces.

I am glad to know that its not an amanda bug or any wrong configuration on my part.

Brandon