running cron backups too much cpu intensive

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lkbryant

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Aug 16, 2005
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hi

i realize that running a backup is a cpu intensive job.
is there any way to do a scheduled backup without eating up too much cpu process?

i've tried rsync to a different server but this too takes a long time as it has to build out the file database first.
i'm just looking into unison and it seems unison is faster and takes less time because of it's sync alogorithm instead of rsync's mirror algorithm.

do any of you guys use unison for your backup purposes? or do you guys just use da's backup tool?

also, i'm just backing up the database and the /etc and /home , is that enough?
 
See this post, you can port it to linux easilly (only the cron line differs) . Run your backups late at night where you have less traffic. If you have a zeon, dualcore or quad cpu you don't have problem as it can use one core for tar and the other for you services.

You can also check nice command (service priority) in http://www.linux.com/articles/58638
 
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Any backup program you're likely to run will cause a high server load. DirectAdmin's backup process does put a high load on the server, but we do it late at night so it is never a problem for our clients. You might want to consider just rsynching the home folder?
 
Is there something more I can do? When my backup runs, my server no longer serves up websites, login thru ssh is slow and sometimes times out, and I can't do anything until the backup is done, which takes a couple of hours. I'd really like to have the backup system work, but 2+ hours of downtime each time is too much.
 
not a lot of users, and only about 20GB of data. Is there a command to check how "nice" the backup service is running?
 
the top command shows how much CPU the application is using and it shows the level of nice it's running.

Anybody knows if Directadmin cron backups use nice?

thanks
 
I have tried to use that utility, but when the backup is running getting into ssh often proves impossible. I just have to wait until the backup is done. Also, what sort of #'s should I expect from the backup utility (provided I can get top to work during a backup)?
 
Maybe install a cron that runs 10-20 minutes after the bakcup starts and logs the data to a txt file? My server is very fast still when doing the backups and it's a single core (right now doing them and I got a 2.5 load average)

I noticed DA backups do use nice level 19:

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
11740 root 39 19 2504 576 200 R 89.8 0.0 9:23.04 gzip

The NI column refers to the level of nice the process is running.
 
For some reason, when I am able to log-in (in-between the frequent outages during backup) I did see that gzip was at nice19, but I don't know what is going on while everything is timing out. Users have reported that they have "unreliable" websites during user-backups, the the problem seems consistant between admin, and user backups.

Any thoughts?
 
Not likely, I have plenty of computing power, and I have a very light load on this particular machine. Besides, a backup should be able to run without intermitantly taking all users, websites, emails everything offline. I confirmed it was the backups causeing the issue by changing the time of the backups. The issue started at the time of backups, so I have been forced to stop running the backups.

Do I need a third party software to run backups? Does DA use one that maybe is broken on my box and I can repair?
 
It's hard to know which of your suppositions are true without a thorough analysis of your system and various load factors. Obviously backups work for a lot of us; I use both sysbk and Admin Reseller backups, and both work well for me.

Perhaps you should be in touch with whomever supports your DirectAdmin installation. If you got your license with a rented server, then that's the server rental company who rents you your server. If you bought a license from the DirectAdmin website, then that would be DirectAdmin Support.

Jeff
 
I own the server, and have it homed in a data-center. My license is one of the lifetime ones.

The computer is a Quad-core phenom 9750, with a pair of 500GB hdds mirrored and a gig of ram. There are only about a dozen or so websites on it, totalling about 1GB of stuff stored. The only databases on it are for gallery2 and the websites don't do much, they are just static. I also use it to do ftp stuff and so the drive usage is about 12GB. The backups run for about 5 hours, and cause the server to slow down so much that the pages don't come up, and I can't ssh in consistantly. It is strange in that there are sparce minutes here and there where I can ssh in and websites do come up. I have confirmed it is being cause by the Admin Backup/transfer by moving the time, and then ultimately disabling it. I initially had it backing up to another server, but then to be sure I started having it backup to a local directory. Problem persisted. The data center called me and told me that their monitoring software reported that during backup times my server was "flapping". When I check "top" it usually reports about 99.5% id, which I assume mean idle. There are times it goes to 98.5%. That usually occurs when a couple IMAP accounts connect. There are a couple huge IMAP account on it (2 are at 2GB).

I don't know what else pertinant to my problem I can give, and I do appreciate any help you can offer.
 
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Even if the cpu was at 100% when backing up it makes no sense that you couldnt login. You might have some faulty hardware.

Can you still ping the machine when its is doing backup?
 
Could be, so I replaced the network switch, ran a scan on the drives and moved the backup files manually using ftp and scp. The problem didn't occur then. It only seems to happen when I use that utility. What does is it use? Is there a way I can check if something is wrong with my copy of the utility? If necessary I can make a backup to another server, then format, reload, and then use the admin/back to put the users back, but that seems extreme. Oh yea, I am running centos 4.6, maybe I should go to 5.2? Would that help?
 
Don't just make changes to see if they'll help. Never a good idea. Never.

I'd suggest contacting DirectAdmin Support; they'll probably help you.

Jeff
 
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