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Swapping SCSI Drives

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by rob baugh 2 views

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I have inherited the following situation:

1 exchange server with 4x18gb drives HW RAID 5(1 hot spare).
We have very few users and Exchange uses less than a gb of space for
everything.

1 File server with 4x9gb drives HW RAID 5(1 hot spare).
Quickly running out of room for users files.

Is it possible to remove one drive at a time from the Exchange server
and move it into the File server while taking the file server's drive
and putting it into the Exchange server, allowing time to rebuild the
drives between swapping the next set? Thus in the end I would like to have the drives from the Exchange server in the File server and the File server's drives in the Exchange server.

6 replies

by wanabedrsean

ABOUT ALL YOU CAN DO IS REMOVE THE HOT SPARE AND TAKE IT OUT OF YOUR CONFIGURATION AND JUST RELY ON THE RAID 5 FOR FAULT TOLERANCE YOU CANNOT PULL A DRIVE OUT OF A RAID SET THEN REPLACE IT WITH SOMTHING SMALLER IT CANT RESTRIPE 9GB WORTH OF DATA ONTO A SMALLER DRIVE IF THAT IS WHAT YOU WANT TO DO YOU DIDNT MENTION WHAT THE DRIVE CONFIGURATION IN THE FILE SERVER IS. THE
FORMULA FOR A RAID 5 SET IS SPACE EAQUALS NUMBER OF DRIVES TIMES SPACE ON EACH DIVE MINUS THE AMOUNT OF SPACE ON ONE DRIVE IFALL THE DRIVES ARE EAQUAL SIZE.IF THE ALL THE DRIVES ON THE RAID SET ARE NOT THE SAME SIZE THEN THE FORMULA CAHNGES A LITTLE THE AMOUNT OF SPACE EAQALS NUMBER OF DRIVES TIMES THE AMOUNT OF FREESPACE ON THE SMALLEST DRIVE MINUS THE AMOUNT OF FREE SPACE ON THE SMALLEST DRIVE. THE SAME GOES FOR PARTITIONS. THE MINIMUM NUMBER OF DRIVES FOR A RAID 5 SET IS THREE. SO A 18GB RAID5 SET MADE UP OF 3 9GB DRIVES IS 9GB x 3 = 27GB -9 = 18GB FOR 6 9GB DRIVES IT WOULD LOOK LIKE THIS 9X6=54GB-9GB=45GB OTHER THAN THAT YOU WILL HAVE TO REBUILD THE SERVER TO MAKE THE ARRAY ANY DIFFERENT

by wanabedrsean

sOME ONE OF YOUR LEVEL IT WOULD PROBABLY BE WELL WORTH THE MONEY TO PURCHASE MORE DRIVE SPACE FOR YOUR FILE SERVER YOUR TIME IS PROBABLY WORTH MORE MONEY TO THE COMPANY THAN ANOTHER COUPLE OF 400 DOLLAR DRIVES WICH ARE DROPS IN A BUCKET FOR MOST COMPANYS IF THEY NEED IT. YOUR TIME IS MORE VALUBLE THAN THIS.

by estebandelatorre

All raid5 disk must be ths same size (or bigger), so the only thing that you can do is to add the spare drive of the file server to the raid 5, so you will get 27 GB of disk
The hot spare of the exchange srv 1*18gb will remain as a spare, but can be used on both servers if one disk fails.
In order to make a complete disk swap, as you wish you will need to do a backup and restore of ghost file image.

by rob baugh

Thanks, that is what I was thinking, but just wanted another persons opinion on it. They say that the measure of a man's intelligence is how well he agrees with you.

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