How much space used by Deleted Items?

[10base2]

NT4 SP6a, Exchange 5.5 Enterprise SP4. Our info store is about 60GB.

We have not implemented any deleted items retention times. The Deleted Item Retention time is set to 0, and the "Don't Permanently Delete Items Until the Store Has Been Backed Up" box is unchecked. I would like to set values for Deleted Item Retention Time, but my boss wants some idea of how much space is being wasted before we start deleting things. What are you folks using as your deleted item retention time? How can I find out how much space is being used by deleted items?

We have hundreds of users, and the backups are taking 30+ hours. Excessive backup times are what's driving this issue.

Tim

 

[yanks2112]

Hello

This option is designed so that users can recover items that they deleted from their deleted items folder. I used to have mine set to 15 days (ridicoulsly long period of time) and my information store more than doubled in a year. Other factors contributed to the growth, but I have a feeling that this was the major cause. To see the deleted items K open Exchange Manager and go to the Properties of the information store and select Mailbox Resources. Choose Columns... and add Deleted Items K. This will allow you to see the amount of space used by deleted items. This is per user, I dont think there is a cumulative total. Its not a bad option, but be careful some of my users had close to a GB of deleted items.

 

[rdroske]

The 0 means you are not retaining deleted items anyways.

 

[zbnet]

Well, setting a Deleted Item Retention time will definitely make your store bigger than it already is, not smaller, so if backup times are currently cauing you an issue... I'd say pause for thought, and perhaps redesign your backup.

How big is your store? Modern DLT drives on fast SCSI connectors can chew through some pretty big stores in minutes rather than hours. My biggest store (33GB) takes 1h23m to backup, and this using a 3-year-old DLT drive.

To answer your other question, we currently have Deleted Item Retention set to 10 days (the 'logic' behind this number is that it is a week plus a weekend plus a day, so if you delete something on a Friday and go on holiday for a week, you can still get it back after you return to work). However, this is proving too small, we still get requests for mailbox restores (because most people who need things back don't realise in 10 days that they need them back), so we are making plans to increase this to 30 days. This will have a significant impact on store sizes (my very rough and ready calculation suggests about 1% increase per extra day of retention), so we're upgrading our RAID5s first on the smaller servers.

 

[10base2]

>The 0 means you are not retaining deleted items anyways.

That makes sense now. I looked at the Deleted Items K as described by yanks2112 and all but a few were other than 0. I was very confused. I misunderstood the meaning of 0. I thought that 0 would not delete anything at any time (disable the feature) rather than to delete items immediately. My mistake. Perhaps I should re-think this setting and make it something other than 0.

<How big is your store?

My store is about 60GB and we have well over 5000 mailboxes. I'm using a Dell LTO2 drive on a Dell Poweredge 6400. The store is located on a fibre-channel attached RAID5 array. I use ARCserve to backup the database and the Exchange Agent to do Brick Level backups. When backing up the store itself, I typically get better than 1GB/Min. When ARCserve gets to the Brick level backup, it slows to 30-50 mb/min. I do a full brick-level and store backup 3 times a week. I'd do it more often if it didn't take so long! Perhaps this is more of an ARCserve issue than a store size issue. How are the rest of you backing up your stores?

 

[zbnet]

Oh, brick-level backup. That's why it's taking so long.

That's a mighty large overhead just to be able to restore individual mailboxes. It's also wearing out your tape device and your media quicker. How often do you restore mailboxes?

I've never worked anywhere that ever did a brick-level backup, and I've working in organisations that had exchange servers numbering in tripple figures. Always used a restore server for mailbox restores - sure it's a pain to build and restore the whole store, but it doesn't have to be a particularly quick or new server, it just needs shed-loads of disk space and an equivalent backup device as your production server. Anyway, with Deleted Items Retention set, and a policy of hiding mailboxes for a month before deleting them, we find the only mailbox restores we need to do are for legal reasons off very old backup tapes - and this in an organisation of a similar size to yours (a few more servers, though!).

If I had a 60GB database I'd think carefully before enabling Deleted Item Retention. That store is only going to get bigger with deleted items. 5000 users are a lot to scream at you when the server goes down. I'd think seriously about adding more servers to the site and sharing the users out over two or three servers.

 

[yanks2112]

I find that brick levels do run slower that the store, but the benefits outweigh the time (ave 80MB/minute for a 14GB store) I do incrementals Mon-Thurs and a full on Friday. The only draw back to this is if I have to do a restore late in the week, I have to do 5 restores. This has only happened once, so its not too bad. I used to backup the store on a monthly basis. This was due to an old tape unit and an old mail server, I have since upgraded both so I do a full store once a week