7019963: Reload Disk Space Sizing (advanced)

If you have a 100 Gigabyte post office, and you want to keep around 14 days of backups, then you generally want about 250 Gigabytes of space on the Reload server.

[+100 Gig – First Backup]

The next night however, a backup takes 10% of the size of the post office. Here’s how it’s done:

1. The databases at the root of the post office and in the OFUSER and OFMSG directories are backed up in their entirety. 2. The Additional BLOBS that have been created on the live post office and are in the OFFILES directory, are copied to the Master BLOBS location on the Reload server. On the average GroupWise post office the daily growth in the OFFILES directory represents about 2% of the total size of the post office.

So Reload has actually done what would commonly be referred to as an “Incemental Backup”. Namely Reload backed up data that changed, and new data. Reload then does this: – Makes the DAY-DATE directory spoken of earlier – Copies the GroupWise databases to their appropriate locations such as OFUSER, OFMSG etc. – Links the OFFILES directory to the Master BLOBS directory So the Incremental Backup is now just as effective and usable as a full backup set. The reason for this is that BLOBS, which represent 92% of the GroupWise Message Store never change from day-to-day. All that Reload needs to do is copy down the new BLOBS that get created, and link to the existing BLOBS.

[+10 Gig – Daily Backups]

Each night’s backup is going to be exactly the same. So at the end of 6 days, the Reload server now has effectly 14 Full Backups of the 100 Gig post office, and the disk space on the Reload server that is allocated to backup that post office is approximately 250 Gig

Let’s say you want Reload to also create the Tape Archive files, and you tell Reload to delete old Tape Archive files. Then add an additional 250 Gig.

= 500 Gig

There are some other factors to take into account to size things appropriately. Reload has a disk space threshold check, that is set at 90% by default. To maintain this feature, you want to allocate an additional 10% of disk space. I think it would also be prudent to add an additional 30% for growth. Even with other Hot Backup solutions you would want to consider such things. So in total, you may want to consider an additional 175 Gigabytes. In total then: 675 Gigabytes

Now if this number seems just too big, let’s tell you how you can tweak it a bit. – You can shave off the Tape Archive Feature – You can reduce the number of Daily Backups you keep

There are some other things to consider when determining disk space. Do you have Document Management Libraries at the post office? Do you intend to have Reload backup up the the Libraries? If so that changes the amount of disk space needed.

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