Page 2 of 2 FirstFirst 12
Results 11 to 13 of 13

Thread: why is raid-5 not recommended for installations with more than 100 accounts?

  1. #11
    schemers is offline Zimbra Employee
    Join Date
    Aug 2005
    Posts
    228
    Rep Power
    10

    Default

    It all depends on the amount of traffic on your system, as well as the size of your mailboxes.

    RAID5 has poor write performance, and when a message arrives there are a lot of writes.

    At a minimum:

    - the whole message gets written to disk

    - its content/headers/attachments gets anaylzed and indexed, which is multiple writes

    - rows are inserted/updated in MySQL, as well as data written to the MySQL transaction log

    - Zimbra has its own application-level journal file for crash recovery

    - there are other log files written to (log4j server-level logging)

    If you aren't having any noticable performance issues, you should be ok.

    In general though, we recommend against RAID5 because in our testing we have seen very bad performance under it, to the point where a moderately loaded system will slow down to a crawl with RAID5, but have plenty of headroom on RAID1+0.
    Bugzilla - Wiki - Downloads - Before posting... Search!

  2. #12
    kollross is offline Senior Member
    Join Date
    Nov 2005
    Posts
    50
    Rep Power
    9

    Default

    I fully understand that portion but i saw the comment that said

    "I have 496 accounts in my Zimbra 3.1.4 with RAID5, so I couldn't migrate to version 4.0.4 "

    And i checking if something major in code had not changed between 3 and 4 in the upgrade that we specifically prevent me from upgrading, and or seeing a huge performance difference between 3 and 4.

  3. #13
    KevinH's Avatar
    KevinH is offline Expert Member
    Join Date
    Aug 2005
    Location
    San Mateo, CA
    Posts
    4,789
    Rep Power
    19

    Default

    Quote Originally Posted by kollross View Post
    I fully understand that portion but i saw the comment that said

    "I have 496 accounts in my Zimbra 3.1.4 with RAID5, so I couldn't migrate to version 4.0.4 "

    And i checking if something major in code had not changed between 3 and 4 in the upgrade that we specifically prevent me from upgrading, and or seeing a huge performance difference between 3 and 4.
    Not at all. We just added the warning to the docs in v4. There is no code changes to make things slower on RAID5. In fact for IMAP things will be faster. If your happy with your system performance on version 3 then you'll be just as happy on version 4.
    Looking for new beta users -> Co-Founder of Acompli. Previously worked at Zimbra (and Yahoo! & VMware) since 2005.

Page 2 of 2 FirstFirst 12

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. recommended RAID level
    By jdunker in forum Administrators
    Replies: 9
    Last Post: 12-29-2009, 04:00 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •