On 29/06/19 2:46 AM, Blake Hudson wrote: > > Nikos Gatsis - Qbit wrote on 6/27/2019 8:36 AM: >> Hello list. >> >> The next days we are going to install Centos 7 on a new server, with >> 4*3Tb sata hdd as raid-5. We will use the graphical interface to >> install and set up raid. >> >> Do I have to consider anything before installation, because the disks >> are very large? >> >> Does the graphical use the parted to set/format the raid? >> > > Hi Nikos, I've read the other posts in this thread and wanted to > provide my perspective. I've used Linux RAID at various times over the > past 10-20 years with both desktop and server class hardware. I've > also used hardware RAID controllers from 3ware, Adaptec, LSI, AMI, and > others with IDE, SATA, SAS, and SCSI drives. The goal of RAID 1 and > above is to increase availability. Unfortunately, I've never had Linux > software RAID improve availability - it has only decreased > availability for me. This has been due to a combination of hardware > and software issues that are are generally handled well by HW RAID > controllers, but are often handled poorly or unpredictably by desktop > oriented hardware and Linux software. > Sorry for your poor experience. I have used and achieved much improved availability by using Linux Software RAID - most often I use RAID 1 and had disks fail with no impact to the client other than slightly reduced response times (in fact they were totally unaware that a drive had failed, until I told them). Replaced the faulty drive (done by a local person who barely knew how to use a screw driver), resynchronized and all is well - zero data lost. It was a hot swap bay and thus the server did not even have to be powered down - zero customer noticed impact - 100% availability. > Given that Linux software RAID does not achieve the goal of RAID > (improved availability), my recommendation would be to avoid it. If > you are looking for a backup mechanism, RAID is not it (use a backup > program instead). If you do need high availability, my recommendation > is to purchase an LSI based RAID controller. If you plan to use RAID > 5, make sure the model you choose has a write cache (this could double > the cost of the controller). Used IBM, HP, or Dell RAID controllers > are available for a reasonable price or you can purchase a new one > from Newegg or wherever. SAS RAID controllers will work with either > SAS or SATA drives and you can purchase the appropriate breakout > cables for connecting the controller to individual drives. Since > you're planning on using 3TB+ drives that are likely 4k native sector, > I'd recommend a newer model controller like the Dell PERC H730 (LSI > MegaRAID SAS 9361-8i) for RAID5/6 or a PERC H330 (LSI MegaRAID SAS > 9341-8i) for RAID 0/1/10. > > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos