Do you do HSM?

[Xueshan Feng <sfeng@stanford.edu>]

I am interested to know the real world experience of Zimbra HSM deployment. I found some archived articles on this mailing list from 2008 about using HSM, but things have changed so much since and I believe there are must be more customers actively using HSM now. 

There is a good wiki page http://wiki.zimbra.com/wiki/Ajcody-HSM-Notes that covers various implementation considerations and setup, but I'd like to know anyone who uses HSM in their production environment has lessons, concerns and 'howtos' to share. Here are my specific questions (with some answers for our university, when applicable). All in all, does it worth to trade potential system performance impact with cheaper storage? 

1. How many user accounts per mailbox server

We have 9 servers, each has about 5000 accounts. 

2. How much mailbox quota per account 

1GB  by default. Additional quota can be purchased. Mailstore disk usage is around 1.5TB on each server. 

3. Storage architecture: do you use different storage for zimbra root /opt/zibmra, and zimbra backup /opt/zimbra? 

We have /opt/zimbra  (database, redolog, logs) on fast disk connected through fiber channel to SAN disks. /opt/zimbra/backup is mounted as NFS partition through Ethernet connection to NetApp server, slower disks.

If you use HSM, what kind of secondary storage do you use? Do you use NFS mounted file system for secondary volume?   

4. Do you have dedicated network connection  to the HSM storage?

We are looking into HSM, but our servers have only one Ethernet interface, and we may need to share that connection used by the backup volume. 

Will it be a performance problem if both backup and the secondary HSM volume share the same network connection?

5. Impact with backups

Our current backups (NFS mounted partition) takes more than 10 hours already, even we use 7-group backup policy. Offering more storage obviously will make the backup runs longer. If HSM process has to run at off-peak hour and  over-ldaps with the backup process,  how bad it can be?  Do you use higher number of auto-group policy, like 14 or 31 auto-groupping? 

6. Impact to server

Obviously moving data from primary disk to secondary disk will have impact to server performance. Do you let your HSM process run continuously? Is the performance impact end user email experience during the business hours? 

7. What HSM Age do you use? If you adjusted it from the default 30 days, why? 

8. When you initially turn on HSM, how long did it take for a complete run? How long does it take after the intial run? 

Thanks!

Xueshan

-- 

Xueshan Feng <sfeng@stanford.edu>
Technical Lead, IT Services, Stanford University

-- 

Xueshan Feng <sfeng@stanford.edu>
Technical Lead, IT Services, Stanford University

-- 

Xueshan Feng <sfeng@stanford.edu>
Technical Lead, IT Services, Stanford University

-- 

Xueshan Feng <sfeng@stanford.edu>
Technical Lead, IT Services, Stanford University

-- 

Xueshan Feng <sfeng@stanford.edu>
Technical Lead, IT Services, Stanford University

-- 

Xueshan Feng <sfeng@stanford.edu>
Technical Lead, IT Services, Stanford University