On Mon, Nov 8, 2010 at 6:52 PM, Stan Hoeppner <s...@hardwarefreak.com> wrote: > ahmad riza h nst put forth on 11/8/2010 3:37 AM: > >> i think it would reach to 12 thousands or less. yes we plan to do it >> in one server but just for mailboxes only (pop3, imap, webmail), we >> have another servers for the mx. > > 12,000 is a lot of users for one IMAP server. You'll definitely need > the hardware upgrades I mentioned in my last email. When you say > webmail, are you planning on running apache/lighttpd and > roundcube/horde/squirrelmail on this same box that hosts Dovecot? If > so, keep in mind you will probably run out of processor power and memory > well before you reach anywhere close to 1,000 concurrent users. >
yes, we understand this issue, the users mainly use pop to access their emails. sometimes when they far from desk at their office maybe they use webmail, but they assumed have smartphone/bb to access emails. >> the problem is webmin + virtualmin won't do it with mysql db virtual >> user, or maybe i'm wrong ? >> http://www.virtualmin.com/node/7616 > > Do you plan on manually typing your current 12,000 usernames and > passwords into Virtualmin, one at a time? If not, I suggest you figure > out a way to get virtualmin to query those databases, or at least import > the data from them. Otherwise I'd highly recommend you pick another web > based management front end. There are many of them freely available. > since this is kind of hosting server for our customers, sure there are admin for each domain respectedly, so i don't create the emails my self. webmin + virtualmin used to help user to admin their own hosted domain. i think i can't do virtualmin hack since im no perl hacker by the way.. :) it would be good if virtualmin hacker do this, so we could use mysql with postfix on virtualmin. > I've not used Virtualmin myself, but I got involved in assisting another > OP on this list who uses Virutalmin. I found its capabilities to be > extremely limiting in some ways. For instance, due to the manner in > which it implements SpamAssassin, it requires you to use procmail for > local delivery. This is horribly inefficient compared to using Dovecot > LDA for delivery. If you are doing your spam filtering upstream at the > MX host or a gateway, I'd highly recommending disabling SpamAssassin on > this virtualmin mailbox server host, if Virtualmin allows disabling it. > yes, we understand this too, there are some limitations.. sure we don't install spamassassin or clamav in this server, just for mailbox (imap, pop) only. > This is just one of the limitations I've noticed. If at all possible, > look to another web management front end that gives you the flexibility > to use your current mysql user database and gives you the flexibility to > use Dovecot LDA. Don't choose one which forces you to configure one of > your services in a far less than optimal matter WRT performance, as > Virtualmin does. > > >> we would do it with hp dl180 g6 (1 xeon quad core, raid1, 4G Ram) > > As I said, add the 2nd CPU, upgrade the RAM to at least 8GB, and add 8 > drives in a hardware RAID5 device on the Smart Array controller. Create > a single partition on the device with cfdisk or fdisk. Format the > partition with the XFS filesystem: > currently we don't have any experience on xfs, i'll keep this for future references. :) > mkfs.xfs -d sw=7 /dev/[device_name] > > The "-d sw=7" switch sets the filesystem stripe width to 7. With an 8 > disk RAID5, each stripe contains 7 data blocks and one parity block. > Using RAID6 this would be "-d sw=6" as there are two parity blocks. > > XFS is superior to all other filesystems when many processes are > reading/writing in parallel to the same filesytem, mainly due to the use > of allocation groups. Also, XFS in the only production Linux filesystem > to offer an online defragmentation tool which can be scheduled weekly to > defragment the filesystem containing the mail store. > > Put the system log directory, Postfix spool directory, and maildir > directory on this XFS filesystem. For the log and Postfix spool > directories, stop the respective daemons, use "cp -a" to move the > contents to directories on the new XFS filesystem, and then create > hardlinks. For Dovecot simply tell it the location of the maildir > directory you create. > > The reason I recommend you put this all on one filesystem instead of > creating 3 and mounting each into the usual places, is that this way you > don't have to worry about preallocating a given amount of disk space to > each. Say you allocate a 20GB partition to /var/spool/postfix and one > super busy day you get a bunch of mail backed up due to a problem at a > popular destination which is having problems difesting inbound mail. > What happens when your outbound spool fills up? Using one filesystem > gives your postfix spool access to hundreds of gigs if need be. There > is a downside: if your postfix spool goes nuts for some reason, you can > fill up a large portion of your massive filesystem. Other may have > different advice, but I think this method offers the best trade off WRT > user satisfaction. > > -- > Stan > -- http://blog.rizahnst.org
