Koozali.org: home of the SME Server
Obsolete Releases => SME Server 9.x => Topic started by: abhijitb on July 19, 2016, 02:12:47 AM
-
Hello Friends,
I am a new user of SME Server. I am installing SME Server 9 on Lenovo TS140 Server. I have configured the harddisks using servers Hardware RAID.
I am using RAID 5 Configuration. While installing SME Server I have selected Manual Partitioning of harddisks.
I am trying to create partitions like /Boot, /Swap, / , and two other partitions for saving my file server Data.
The interface is showing 3 Hard disks. But when I create a partition it is getting created on just one of hard disk out of 3 hard disks.
I want to know if SME Server supports Hardware RAID. (My server is Lenovo TS140) or I have to go with software RAID provided by package.
Thanks.
-
The wiki is the bible :-) at least usually has an answer.
https://wiki.contribs.org/SME_Server:Documentation:Administration_Manual:Chapter5#Hardware_Mirroring
-
I want to know if SME Server supports Hardware RAID. (My server is Lenovo TS140) or I have to go with software RAID provided by package.
Yes, SME Server supports (most) hardware RAID. But if it sees 3 drives, then, the problem is on your RAID controller, not SME (SME should see one single, big drive). My guess is that your server doesn't support hardware RAID, but only Fake RAID. In this case, you'd better use the software RAID provided by SME
-
As another point in the mix....(apart from saying you most likely have 'fakeraid' and not real hardware RAID)
3 drives in RAID 5 however you do it is a disaster waiting to happen....
Have a REALLY good read online (try googling 3 drive raid 5) before you go down this road, and if you do make sure you have good TESTED backups...... you are probably going to need them.
Yes Koozali SME will support lots of different RAID/drive configurations. 3 drive RAID 5.... Would you really want to use it ? Errrrrrrrr
B. Rgds
John
-
Unfortunately most small servers from Lenovo, HP, Dell etc no longer have real on-board RAID, it's firmware assisted BIOS raid. AFAICS the Lenovo in question has Intel Intel® RSTe which is one of the above. Real RAID cards cost more than small servers, sadly...
Here's the Intel docs for Linux support:
https://www-ssl.intel.com/content/www/us/en/support/boards-and-kits/000006376.html (https://www-ssl.intel.com/content/www/us/en/support/boards-and-kits/000006376.html)
- which specifies "using Linux* MDADM" ie software RAID. So that's what you use.
A few hints:
1. Don't use RAID 5 if you have SATA disks
2. Really, don't use RAID5 even on SAS
3. Actually just don't use RAID5
RAID5 was wonderful when disks were small, now it will bite you.
More hints:
1. Use RAID1 or 10 or 6
2. Unless you have more than 6 drives use RAID 1 or 10
3. Don't use hot spares without a proper RAID controller and RAID 6 and SAS drives
So if you have 3 SATA drives use them in RAID 1 (with three drives) then it does not fall over in a heap when you lose one drive and the system tries to re-stripe the hot spare causing the other disk to fail :)
Speaks the Voice of Experience (tm)
MeJ
-
3. Actually just don't use RAID5
RAID5 was wonderful when disks were small, now it will bite you.
In a nutshell !
Reason being (for the OP) with larger drives there is a high chance of another drive failing during the rebuild which will kill you (I have seen the theory on the linux raid list which shows you can rebuild a RAID 5 from one disk - assuming all the data and parity would fit). Some ugly maths involved, and it would not be something I'd like to see !
So if you have 3 SATA drives use them in RAID 1 (with three drives) then it does not fall over in a heap when you lose one drive and the system tries to re-stripe the hot spare causing the other disk to fail :)
+1
Speaks the Voice of Experience (tm)
ROFL....
-
I second all the good words above.
So if you have 3 SATA drives use them in RAID 1 (with three drives) then it does not fall over in a heap when you lose one drive and the system tries to re-stripe the hot spare causing the other disk to fail :)
the result might be quite slow write access, but it is a good way to do,
or use the third as online or spare backup ( meaning you actually use it to do backup of data)
or use it as cold spare ( meaning you keep it in the blister, after testing it, next to the machine ready to replace manually a failed drive whenit occurs)