Adaptec HW RAID 31605 Expandability?

You can add 8 more drives in the future and expand the size of the array you already have. I assume you would use the same drives. This will give you a windows volume larger than what you have. If you want to keep all this in 1 drive letter you will need to either resize the partition you have or delete and re-create the partition.

So, I'm assuming there's no way to expand the array via the hardware controller? The array is formatted in NTFS, so I guess in Windows there may be issues with expandability, but is there no way to expand the arrays and create a partition through parity rebuilding into one large, contingious partition without having to backup/dump/restore?

When you say expand the array via the hardware controller and create a partition through parity rebuilding into one large, contingious partition without having to backup/dump/restore, those are 2 different steps. Expanding the array is 1 step which in windows will give you more useable space on the volume. In disk manager for instance if disk 1 were your array you will see more unpartitioned space on that disk. Step 2 would be in windows and this is how you use that space, you can try to resize the partition you have that has data on it now and use the entire volume/disk to be 1 drive letter/partition or you can delete the partition you have and re-create it using the entire volume and have it all in 1 drive letter in windows.

I do not know of a utility that will re-size a partition that big, maybe somebody reading this can help. I assume it is a GUID Partition formatted NTFS now and about 4.7 TB in size.

Windows XP x64, Windows Server 2003 SP1, Windows Server 2008, and Windows Vista have a built-in command line utility called DISKPART that can expand a GPT data partition.

See this thread for details.

Using this method, would this mean that any sort of RAID would be software-based? I created my initial array using the Adaptec controller, and then formatted in NTFS with Windows Server 2008; would this method tie me down to my current OS install in terms of the NTFS DISKPART file system?

No. The file system (NTFS) and the RAID operation are two different things.

The RAID operation is the portion that is responsible for taking several physical drives and using one of several different redundancy schemes (like RAID 1, RAID 5, or RAID 6) to make the several physical drives look like one logical drive to the computer. The RAID operation can be software-based (done primarily in the driver software), or can be hardware-based (the RAID controller performs all functions).

The file system is responsible for creating a partition on a device and creating directory structures to keep track of all the files. The file system's tasks are always software-based, and are part of the operating system. Windows uses primarily the NTFS file system. Linux OS's typically use EXT2 or EXT3 file systems. There are others for other OS's.

If you have a RAID array and want to expand its size without losing data, that is a 2-part operation:

1. The RAID controller must be able to add a drive to the array and rearrange the data and redundancy information so that the logical drive looks bigger. Most hardware-based enterprise-level RAID controllers can do this, they generally call this operation Online Capacity Expansion (OCE). This operation is independent of the OS on the computer. Thus, you have to do this step whether you're running Windows, Linux, or anything else.

2. The second step is to expand the partition that's on the logical device so that the computer and OS have more space to actually store more files. This operation is dependent on the file system that was chosen, and expanding the partition without losing data is a task that only a few software programs can do.

Software programs that can expand an NTFS partition without losing data include Symantec's Partition Magic, the freeware GParted, and a few others. However, all of these suffer from a particular problem - they don't work with partitions that are larger than 2TB. Your array is larger than this, so you need a different tool.

The DISKPART program is a tool that can expand an NTFS partition that is larger than 2TB. You would run this according to the instructions I previously referenced to expand your partition (after you've performed the OCE via the RAID controller software).

Thanks so much for your info, that was exactly what I needed to know!

The term "Online Capacity Expansion" makes Google searching much, much easier.  

Kudos.

I`ve tried to expand 7x750gb>16x750gb raid5 volume (initial volume was stuffed to its fullest - 300mb free)

it took 3 days (yep, its 72hrs +-3hr) to progress for whole three(3) persents(%).
i`m using it in generic chieftec bigtower and was really scared to burn my hdds to hell with such kind of work (it sounded like drives were under really heavy load, and for generic sata drives(seagate barracudas), such kind of usage is not a good thing (as in 'fatal'), in my opinion)

the bad thing with current state of storage solutions is that the cheapest way to backup data for large soho fs - not really fast but bigger than 10TB - is to buy\rent(try to find if anyone could rent you lots of large hdds, lol) hdds.

Here to bump this thread after many months of working with my Adaptec RAID card.

I appreciate this forum's help when I was a newbie back in Summer, and in a lot of ways, I'm still learning stuff about storage and RAID and whatnot...so here goes.

The Adaptec controller, I will also confirm (as well as another forum thread I posted on [H]ardForums) is DEAD slow in Online Capacity Expansion.

I've done a 6-disk RAID 6 to a 8-disk RAID 5 for an experiment and it took a good part of a month to complete; even Adaptec technical support confirm that it takes a boatload of time to complete an expansion.

For this reason (and various other reasons that are less of an importance), I'm probably going to move to a 3Ware 9650-16ML as that controller card seems to have generally greater performance over the Adaptec as well as much, much faster OCEs.

Unless anyone can chime in as to their personal experiences with OCEs with 3ware (and any other card for that matter), please let us know! The more information we know, the better.  

I have the Adaptec 31605, I can absolutely confirm the slowness of the OCE and migration. I had 8 1TB drives in RAID 5. Put another 8 drives in and migrated to RAID 6 as well as OCE to all but one I set as hot spare. 1 day, 3% done. Would have been faster to offload all the data and start fresh.

So just a quick update... 30 days later and the OCE and migration are complete. Minor problem, almost all my media files are now corrupted, mp3's skip and videos crash.

Additionally just to add to the situation, Adaptec does not play well with Dynamic disks for OCE or migration, so the array was set to a GPT in windows. Diskpart refused to extend the volume for an unspecified reason.

My backup is a bit out of date, but at least I have something to go on!

Should have went with the Areca 1680ML  

Interesting. Last year after I created a Raid 5 set with one hot spare on the Adaptec 31605, I spoke with Support about expanding the raid set. The answer I received was for optimized speed with Raid 5, do not expand beyond the 8 drives, rather create another 8 drive raid set off the 31605.

He also explained the reduced risk to the data on the original set due to the possibility of a drive failure during an expansion of the raid set.

It sounded reasonable to me, and this is the way I went.

I can totally attest to the speed (or lack thereof) of adaptec oce. I'm still waiting for my 4x1.5tb raid 5 array to expand to a 7x1.5tb raid 6 array and it's progressing at roughly 1% per 12hrs. Totally insane. How they allow their product to be this slow is beyond me. Other than that I've been quite happy with it.

Let me add to this thread my two cents.

I'm trying to do online capacity expansion with Adaptec 6805, adding wo 3TB HDD to extisting 12x3TB SATA HDDRAID6. It took almost 48 hours to progress to 21%. The array is almost offloaded. Actually I'm amazed how bad OCE feature is implemented by Adaptec - no redundancy as you go, disks are highly-overloaded (blinking constantly), overall system performance is impacted (max speed is 50mb/s), no way to cancel this process. I think they shouldn't have created this feature at all.

This topic has been closed by Mousemonkey