My Terastation saga
23/10/08 19:38 Filed in: Hardware
Haa the Buffalo
Terastation, oh how I love/hate thee!
Yes I have to manage 12Tb’s worth of Terastations at work and well, it’s been a long story...
Yes I have to manage 12Tb’s worth of Terastations at work and well, it’s been a long story...
Yes, I have under my management 12 Tb of storage
across 10 Terastations of various different versions
(which is part of my problem)
This storage is used to keep the museum’s photo and film archives which are as might guess are large! Most of the Terastations are showing 96% to 99% full. Thats a lot of data!
The system had been set up well with 5 of the stations in the archives being the working copies and these where backing up to another 5 in a different building connected by a fiber link, so a fire wouldn’t lose the data. This sounds fine but for the minor problem that the main building suffers from a lot of power cuts and the Terastations don’t come back up after power loss.
Now mainly due to me not knowing where these lived I hadn’t been checking them and they had been down for some time and hence where way out of sync!
The first thing I did was to move the things in to ‘my domain’, which is the server room. The solved the power and checking problem (I have lots of UPS’s there). Also since I could now plug them in to the switch that handles the fiber link, which has to be (slightly) faster than the 10 meg hub they where plugged in to before.
Now I had to worry about backing up 100 of gigs of changes that have stacked up since the last time the backup units where on line. To explain the Terastations do have a backup capability built in. In theory they will see other Terastations on the network and will very simply back up to them. I say in theory, because this only works well, or at all, if both ends are on the same version of the software. This did become a problem for me, again largely due to me jumping to a silly conclusion.
One of the backup stations had a drive go bad, now the main problem I have with this set up is that to get all of the data we need in to the system most of the stations (all but 2) have been configured with all 4 drives in spanning mode, otherwise known as scary RAID. Lose one drive you lose the array. This means the backups are very important.
Any the backup unit with the bad drive was an Terastation 1 which meant, I knew from previous experience disassembling the whole thing (taking out 22 screws in the process). Now I knew I could get away with 3 drives in this thing, just. So I when to configure it as a 3 drive RAID 5 array. It wouldn’t let me do that. I could have a RAID 1 array using 2 drives and that was it.
That was not enough space.
But why can’t I have a 3 drive RAID 5 array? It’s theoretically possible, so I jumped to the conclusion it was a software problem, since this had version 1 of the firmware and when for an update.
Of course I know relalise that while a 3 disk RAID array is possible, it is not a true Redundant Array of Independent Disks, because it is the minimum that RAID 5 will work with, so if I lost a disk I would lose the array. 4 is the minimum number of disks that you can have in a RAID 5 array and still be able to lose a disk without losing data.
I didn’t think of this until after I had done the update. The update it’s self didn’t go so well. The software had not been originally written in English and the translation was not good. This worried me. If I got this wrong I could end up with a large expensive ‘brick’ and in fact this what appeared to happen. I was sure I’d killed the thing.
I’d given up and had been working on other ideas for backing up this data when at the end of the day I deiced to try powering the thing up one more time. This it worked and what’s more it had been updated!
Now I though my problems where over, but no now I had a different problem. The main and backup stations where now on different versions and would not see each other. I’ve not yet come across any one else on the internet that has had this problem but looking at all of the different versions I have this seems to be the case. They need to be on the same version.
So now I had to update the main station, but given my experiences with the backup I was not going to do this without some form of backup. I wasn’t going to be the one to lose 600 gigs of data!
This had to be done as a ‘manual’ copy, i.e not using the built in backup capability. To do this I installed a PC and used the SyncBack software. As I type this is probably about 6 hours from completing, having been running for 2 days! The fiber link is the bottle neck here. Anyway once that is done I can do he update, then do the proper backup and then I will be up to date, some 2 weeks after discovering the problem!
So my thoughts on the Terastations? They are cheep and I mean this in both the good and bad ways. There is only the Drobo out that at a similar price with the same sort of features. However they are not hot swappable (at least the version 2 models you can swap a drive in about 2 minutes) and the software on them is not the best, version 1 Terastations are slow on windows file shares and the back up is not that reliable (I had to restart several times a 800 gig backup job). Things have got better with version 2 to be fair.
Would I use one at home, given my paranoia about back ups?
No, for two good reasons, 1 at the moment I can’t afford it and 2, when I can afford it, I will go for a Drobo!
This storage is used to keep the museum’s photo and film archives which are as might guess are large! Most of the Terastations are showing 96% to 99% full. Thats a lot of data!
The system had been set up well with 5 of the stations in the archives being the working copies and these where backing up to another 5 in a different building connected by a fiber link, so a fire wouldn’t lose the data. This sounds fine but for the minor problem that the main building suffers from a lot of power cuts and the Terastations don’t come back up after power loss.
Now mainly due to me not knowing where these lived I hadn’t been checking them and they had been down for some time and hence where way out of sync!
The first thing I did was to move the things in to ‘my domain’, which is the server room. The solved the power and checking problem (I have lots of UPS’s there). Also since I could now plug them in to the switch that handles the fiber link, which has to be (slightly) faster than the 10 meg hub they where plugged in to before.
Now I had to worry about backing up 100 of gigs of changes that have stacked up since the last time the backup units where on line. To explain the Terastations do have a backup capability built in. In theory they will see other Terastations on the network and will very simply back up to them. I say in theory, because this only works well, or at all, if both ends are on the same version of the software. This did become a problem for me, again largely due to me jumping to a silly conclusion.
One of the backup stations had a drive go bad, now the main problem I have with this set up is that to get all of the data we need in to the system most of the stations (all but 2) have been configured with all 4 drives in spanning mode, otherwise known as scary RAID. Lose one drive you lose the array. This means the backups are very important.
Any the backup unit with the bad drive was an Terastation 1 which meant, I knew from previous experience disassembling the whole thing (taking out 22 screws in the process). Now I knew I could get away with 3 drives in this thing, just. So I when to configure it as a 3 drive RAID 5 array. It wouldn’t let me do that. I could have a RAID 1 array using 2 drives and that was it.
That was not enough space.
But why can’t I have a 3 drive RAID 5 array? It’s theoretically possible, so I jumped to the conclusion it was a software problem, since this had version 1 of the firmware and when for an update.
Of course I know relalise that while a 3 disk RAID array is possible, it is not a true Redundant Array of Independent Disks, because it is the minimum that RAID 5 will work with, so if I lost a disk I would lose the array. 4 is the minimum number of disks that you can have in a RAID 5 array and still be able to lose a disk without losing data.
I didn’t think of this until after I had done the update. The update it’s self didn’t go so well. The software had not been originally written in English and the translation was not good. This worried me. If I got this wrong I could end up with a large expensive ‘brick’ and in fact this what appeared to happen. I was sure I’d killed the thing.
I’d given up and had been working on other ideas for backing up this data when at the end of the day I deiced to try powering the thing up one more time. This it worked and what’s more it had been updated!
Now I though my problems where over, but no now I had a different problem. The main and backup stations where now on different versions and would not see each other. I’ve not yet come across any one else on the internet that has had this problem but looking at all of the different versions I have this seems to be the case. They need to be on the same version.
So now I had to update the main station, but given my experiences with the backup I was not going to do this without some form of backup. I wasn’t going to be the one to lose 600 gigs of data!
This had to be done as a ‘manual’ copy, i.e not using the built in backup capability. To do this I installed a PC and used the SyncBack software. As I type this is probably about 6 hours from completing, having been running for 2 days! The fiber link is the bottle neck here. Anyway once that is done I can do he update, then do the proper backup and then I will be up to date, some 2 weeks after discovering the problem!
So my thoughts on the Terastations? They are cheep and I mean this in both the good and bad ways. There is only the Drobo out that at a similar price with the same sort of features. However they are not hot swappable (at least the version 2 models you can swap a drive in about 2 minutes) and the software on them is not the best, version 1 Terastations are slow on windows file shares and the back up is not that reliable (I had to restart several times a 800 gig backup job). Things have got better with version 2 to be fair.
Would I use one at home, given my paranoia about back ups?
No, for two good reasons, 1 at the moment I can’t afford it and 2, when I can afford it, I will go for a Drobo!
|