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i.mannion@m3c.co.uk

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We have recently upgraded to KMS 6.5 but it has not addressed critical performance and stability issues with Outlook. Users regularly experience slow/locked up performance and Outlook crashes.

My question is whether there is a link between users mailstore size and perfomance using either Outlook connector - there isnt using Thunderbird.

Issues:
Slow performance
Crashes
Mails received on phones/pdas and Thunderbird received sometimes hours ahead of Outlook
Public and Shared calendars not refreshing on change/deletion of items
Massively fragmented local Outlook connector database
errors such as
: ../../btree/bt_search.c:83: __bt_search: Assertion `(h->flags < 0x40) && "corrupted database detected"' failed.
and repeated mailserver crashes
Other errors

Some info:

We have 150+ users
Our total live mailstore is currently 514gb
Average mailstore size is several gb
Some users have up to 20gb mailstores
KMS server runs on a dual core dual processor Dell 1850, 2gb Ram
Mailstore is on a RAID 5 disk array (10k SCSI disks - Powervault 220s array with a 256mb perc RAID card)
Running on Redhat EL4.

I had to fight to prevent the board in our company insisting we move back to exchange following serious perfomance issues but it seems this may not have fixed them.

What is the Kerio line on mailstore sizes? What are other users experiences?

[Updated on: Tue, 01 April 2008 13:19]

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rinzwind

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Quote:


Our total live mailstore is currently 514gb
Average mailstore size is several gb
Some users have up to 20gb mailstores
KMS server runs on a dual core dual processor Dell 1850, 2gb Ram
Mailstore is on a RAID 5 disk array (10k SCSI disks - Powervault 220s array with a 256mb perc RAID card)


If you move back to Exchange let me know if things work out Wink
Don't know if Outlook or Exchange likes a mailbox of 20 GB...

You need some policies regarding mailbox usage. It isn't a file archive!

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sedell

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i.mannion<_a.t_>m3c.co.uk wrote on Tue, 01 April 2008 04:47

We have 150+ users
Our total live mailstore is currently 514gb

That's insane. And I thought our mail store was way too large at 60 GB. Sounds like you may need to revise e-mail retention and/or usage policies.

The volume of mail could account for most, if not all of the problems you are seeing.

Even Outlook on it's own has problems with that much mail. Generally speaking, Outlook doesn't like mail stores much bigger than a few gig. Anyone who's experienced PST or OST corruption can attest to that. It's been better in recent versions, but still has it's limits.

Scott
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i.mannion@m3c.co.uk

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I know, I've been fighting for this for a while but the "business" line as a time-billable consultancy is that its better to chuck money at equipment than have users adhere to mail policies so their time is spent on billing. Totally mad, and unfortunately only when things stop working do you get listened to. And now this lunacy is biting back......

I just need to be able to demonstrate that what we have is no longer a tenable situation and provide some feedback from folk more sensible than myself.... More fool me for keeping it up and running for this long, making it mostly my fault.... aargh!

Thanks for your feedback so far.

[Updated on: Tue, 01 April 2008 14:37]

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scottwilkins

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i.mannion<_a.t_>m3c.co.uk wrote on Tue, 01 April 2008 11:47

My question is whether there is a link between users mailstore size and perfomance using either Outlook connector - there isnt using Thunderbird.

What is the Kerio line on mailstore sizes? What are other users experiences?


Our experience so far is the KOC is a bit slower in 6.5.0, but KOFF is blazingly fast. From your post it seems that you are only using the online KOC, and not the offline KOFF version. Is that correct? If so, I'd recommend moving to the offline version a.s.a.p.

I've run Exchange servers before, and you won't see much if any improvement over your current situation if used in the same manner. Of course Exchange environments default to an off-line state for the client, so it will appear faster. But if you use Kerio's off-line you should see an increase in speed for the end user. Plus, you'll have a whole different set of issues to contend with in Exchange. The grass really isn't any greener... Smile
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i.mannion@m3c.co.uk

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Thanks for the feedback Scott. I should have been a bit clearer - we did the upgrade and put about 10 users on KOFF to test, but thats when we started having the real problems culminating in the server falling over pretty regularly today.

My experience with KOFF (first to move over) is that its has some bugs and quirks, to be expected with a radical departure and we presumably like others who like Kerio so much are more than willing to put with while they get sorted (and I'm sure Kerio must be wading through loads of reports/dumps etc at this moment) but in general a tremeduous leap forward. Its cracking.

But then we started moving more folk across and its degenerated into an email encrusted bunfight. We noticed some obvious drawbacks straight away, to be expected with a ludicruous mailbox size, and were foolishly hoping that the KOFF would paper over the problems with user policy until we could convince management to see sense, also to investigate any other creative solutions.
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My IT Indy

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Set expectations on what the technology is capable of achieving for them. It's completely unreasonable to expect the impossible.

Basically, you tell your company they can yell and scream at the server all they want, but the server ultimately dictates usage policies for the company.

-
My IT Indy
Kerio Certified Reseller and Hosted Provider
http://www.myitindy.com
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scottwilkins

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I hoped you might have tried KOFF. It's definately a different animal.

Here's some more input from our experience.

Fortunately we have not seen any server crashes or such. From re-reading your original post, I'd definately get Kerio support on the phone to work through your issues. You may have a database error that could be corrected by them.

I've noticed that the initial sync in a move from KOC to KOFF is VERY resource consuming. Both on the client, if not all clients, and on the server. I've changed to be sure to migrate only one KOFF user at a time. I also try to keep the user from using Outlook while the initial sync is occuring. I've seen one client firebird crash after KOFF install and the users jumped into using Outlook right away. Of course that was an easy fix, just delete the profile and re-create. I love that! In the future the add of new users won't be a problem as we'll only add one person periodically so performance issues won't get seen so badly.

Just for comparison, I have a user base of about 85 with 100G of storage, and 7 gig at the top user. I moved that top user first, and he's been working extremely well since. We did have to stop KOFF installs due to an obscure attachment bug that affects us, and probably not any others. Our (very old and bad) voice-mail and fax system sends attachments to the users, and in KOFF they are often "MIA" even though they are actually there. That's to get fixed in 6.5.1. But, at this time our KOC users are complaining about slowness a little more than before. Since some of the are heavy users of the voice mail system I can't move them until that weird bug is fixed.

I have to agree that KOFF still needs some polish. And it's getting it too, as I think 6.5.1 will be much cleaner and faster from the bug fixes I've been told about. Personally I think this version of Kerio should have been 7.0 as "new" as it is. And like many new software packages, it's not perfect. It is a major step in the right direction for kerio though. I thinking that Kerio is probably looking to move to one connector only in the future, removing both KSP and KOC entirely and only supporting KOFF. It does after all do the same function as the other two.

Anyway, I think your crashes and database errors really need some TLC directly from Kerio, so be sure to contact them.

(p.s. I just saw HoosierMac's post, he is so very correct. But trying to explain that to the non-technical is often impossible. Good luck.)
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sedell

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The size of the mail store greatly affects performance. KOC was slow with large mail stores, and by large I mean 1-2GB or less (it seemed more dependent on the number of messages). Every time a request is made in Outlook, you have all the server disk IO to deal with, network latency, etc.

KOFF generally takes care of that with the local cache, but with as much mail as you have, it may even make it worse. PCs weren't designed to maintain databases that large - the hardware generally isn't up to the task, and you have desktop apps competing for system resources (not to mention impatient users mashing buttons try to speed things up but making things worse). I don't know if anyone has tested KOFF with 20GB or more mail stores. I certainly haven't, and I can't see many having a need to as it's pretty excessive.

Migration may not be an option either. I couldn't picture how long it would take to migrate that much mail. The last time I had to look into a large mail server migration, I was told to expect only about 10GB per day of mail transfer.

The first thing to do is get the volume of mail under control. Then start looking at performance issues.

Scott
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i.mannion@m3c.co.uk

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Well said HoosierMac! Unfortunately for the innocent bystanders thats whats happening right now...... And thanks again Scott, very similar to what we tried (only we have been rightly stuffed) I wont need any extra fibre for a while Wink

A lot of people, especially those who are recent-ish joiners and are used to sane mailbox policy, automatically keep their mailbox sensibly tidy. But they are being affected by those who have been here a while and are used to getting their own way. I guess thats what happens when the MD thinks they know enough about IT to set policy and IT (and at that solely my fault) is stupid enough to run around trying to keep it implemented - and not going toe-to-toe when you know you are right.

I guess the lesson learned is if you know youre right but users dont understand, maybe Re-Neducate them with some "engineered/simlutated" crashes and horror stories round a campfire. Thats what I hoped to get from the forums, some "you idiot!!" feedback I could relay.

I'm in touch with support and they are on the case with supplied core dumps etc. We are symptomatic of a technical issue taken to an extreme so if they can't provide a fix at least in looking at our problem there may be accidental benefits for other users of the offline syncing.

Thanks again all - good product, nice users. A top combo. Smile

[Updated on: Tue, 01 April 2008 15:51]

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i.mannion@m3c.co.uk

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Thats the plan. I just have to find some way of making it the MD's idea...... Smile


If it helps anyone else we've uninstalled KOFF from all of the test group and the crashes have all but stopped.

[Updated on: Tue, 01 April 2008 16:00]

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scottwilkins

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sedell wrote on Tue, 01 April 2008 15:39

PCs weren't designed to maintain databases that large - the hardware generally isn't up to the task, and you have desktop apps competing for system resources (not to mention impatient users mashing buttons try to speed things up but making things worse). I don't know if anyone has tested KOFF with 20GB or more mail stores. I certainly haven't, and I can't see many having a need to as it's pretty excessive.




I have to disspell one possible myth: According to my DBA buddy, in a modern relational database size doesn't matter. Due to indexing and link management the size of a database could be infinite on any hardware and single access requests will be performed at the same speed no matter the size. PC's can handle any size database.

Not that your statement was wrong, you are correct in that if the number of requests to the database grows large, due to large message store action/read/write requests, or impatient users mashing buttons repeatedly, then no matter how capable your hardware is it will suffer. Even a large system can suffer access to a small database if the request load is too high.

Something I find interesting is that so-called "free unlimited" e-mail services available on the web now (Yahoo, MSN, Google) are usually only 1 or 2 gigabytes in store size. How do they consider that "unlimited"?!?! Wink I use that with my users to give them a good point of reference for my "you need to manage your data" suggestion. Not sure it helps much...
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i.mannion@m3c.co.uk

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When your point of reference is "as much as possible!!!" any helpful pointers to get users heads around whats technically possible/acceptable is very welcome.

Its been obvious for a while that things were amiss with the system (policy and server) so given the past days shenannigans I'm almost glad, its finally forced the issue and the server is still somewhat standing. Just because theres nothing stopping you doing something doesnt mean its a good idea. No more running with scissors..... even though it looks like fun. I should have posted this literally years ago.

It might be helpful if Kerio put some guidelines in their documentation (or maybe they do and I should RTFM) so people can point knowingly at the chapter and remonstrate foolish folk who think things can be made limitless and dont listen to their IT departments.
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sedell

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I've done it on occasion for testing purposes, and it really does matter, especially since larger databases want to load more into active memory. The system usually chokes on it, either the drive or the interface isn't fast enough, there are processes competing, or because there isn't enough memory and the swap file gets clobbered. Now if you have a PC with nothing else on it, and all it does is run the database, it's a different story. That'll do a decent job on a lower transaction DB. But, throw some running desktop apps and an active AV scanner into the mix - the software that a user would be running on a typical all-I-use-is-MS-Office desktop - and it's generally not pleasant.

Scott
i.mannion@m3c.co.uk

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One common thing we found after the inital sync completed was the fragmentation of the database file/tablespace, especially if the user was beavering away while it was syncing, was pretty bad.

In many cases (but then given that some of these files ended up being 3-9 gig no surpise) the file was in up to 7,000 fragments. I dont know if thats acceptable if they arent "really" fragments as far as Firebird is concerend, but if they are I'd imagine that would really give Firebird/Koffbackend the hump.
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