Shulou(Shulou.com)06/03 Report--

As an Exchange administrator, in the process of managing the exchange server, he often encounters some problems, such as the log is too large, the exchange database file is too large, and so on. Recently, it is found that some administrators have proposed how to deal with the stm file being too large. Some netizens suggest that .stm files should be deleted. Exchange re-related service will produce a new .stm file, which is OK, but it is not recommended. Even if you have made a backup before deleting STM files, it is not advisable. If you delete the .STM file, it means that you have also deleted the edb file synchronized with stm. What does this mean? it means that all the messages stored on the server will be lost. Some people say that I have made a backup, and I call those files to restore a backup file. Rehanging the storage group is not OK. It seems to be OK, but this is not the best solution. It is like reinstalling the system when there is something wrong with the computer. Regardless of major or minor problems, reinstalling the system, of course, OK, is not necessarily the most efficient. The key is that we should learn how to find and solve problems.

We all know that the database file of exchange is made up of EDB. In fact, stm is also part of the exchange data file. Since they are all exchange database files, what is the relationship between them?

In early exchange versions, such as exchange 5.5, which had only EDB files, Microsoft positioned EX primarily as an internal mail system, using the MAPI protocol, which is also Microsoft's proprietary protocol, and the role of EDB files is specifically optimized for this protocol. But in the actual operation process, we actually not only use EX5.5 to receive internal mail, but also receive mail from INTERNET. MAPI is not a standard protocol, so every time we receive INTERNET mail, we need to do a format conversion process. This obviously affects the performance of the EX5.5 mail server.

In EX2000 and later EX versions, Microsoft has added support for INTERNET mail, which is the source of STM files. The MAPI format is RPC and binary standard, while STM is plain text plus some MIME encoding format, which makes it impossible to store them in the same database. So in EX2000, Microsoft began to use EDB and STM files to save messages in two formats. And a reference and association are established between the two files. For users, its mailbox is actually made up of EDB and STM files. In addition, it is important to note that the user's mailbox structure is retained in the EDB file. So EDB files are more important. So how do EDB and STM work together? Let's analyze it in several scenarios.

Scenario 1: the user uses OUTLOOK (MAPI) to send and receive mail

In this scenario, the user submits the mail to the database through the MAPI protocol and is directly saved in the EDB file. When the user accesses the mail in the mailbox through MAPI, if the accessed mail is in EDB, it will be returned directly. If it is in STM (such as foreign mail), the conversion will be performed, and the STM will be converted to EDB file format and then returned to the user.

Scenario 2: users access using standard SMTP/POP3/IMAP4 and other protocols

Users use non-MAPI protocol to submit mail, the content is saved in the STM file, but because there is a mailbox structure in EDB, STM does not, so the system will extract the important information of the email and put it in the EDB. When the user uses MAPI to extract mail, the process is the same as above, and when the user accesses it through the standard protocol, it also needs to be converted to STM file format and returned.

These transformations take place in the background. It is transparent to the user. From the above description, you will see that these two documents are closely related to each other. Therefore, we should not operate these two files alone at any time, they are a whole. It should also be noted that no matter how the user accesses the mailbox, it is necessary to request mailbox structure information from the EDB file.

The above is the principle analysis, so how on earth can we solve the problem that the .stm or .edb file is too large? Personally, I think the treatment can be divided into three steps.

The first step is to open the storage group through the exchange manager to clean up the mailboxes of deleted accounts. At the same time, you also need to check the accounts that have resigned but the mailboxes are still retained, and whether the mail in these accounts needs to be received. There may be two or three reasons for this. One reason is that some users have of course left their jobs. For example, colleagues in the sales department, mailboxes need to be temporarily retained. The other part is that the travelers use OWA to operate, and the contents of the mail are kept on the server; the third reason may be that when the IT manager is configured, the mail is not kept locally, or caused by misoperation by the user, or by POP3, and the backup is kept on the server. These messages retained on the server over time will seriously affect the burden of the exchange database. We classify this part according to the period category. If we can keep it on the client side, we will keep it on the client side. The unimportant ones should be cleared immediately, and the rest of the important ones will be kept on the server.

Step 2: compress the personal mailbox on the server with the command: C:\ > eseutil / d / priv.

The third step is offline defragmentation, or defragmentation. In fact, exchange not only has the function of offline finishing, but also has the function of online finishing, offline finishing is only needed in special circumstances, generally, there is no need for offline finishing, because online finishing is enough. Offline sorting requires unloading storage, the mail server does not work properly, and is generally only suitable for night or non-working hours to perform this work. Command:

Cd c:\ Program files\ Exchsrvr\ bin\

Eseutil / d.. / mdbdata/priv1.edb .

After performing the above three steps, restart the exchange-related services, I think there should be a significant change in the size of the exchange database.

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