pro 4 - incorrect total volume reported and lun setup
we have a backup pro 4 using os 6.10.8 which is populated with 2 x 10 tb (9.1) and 2 x 16 tb (14.6) disks running x-raid (raid 5). no snapshot space is allocated to or used by any of the thick luns set up on the system, so as i understand it, the total volume size should equate to approximately 32.8 tb of usable space. however, our total volume reports 27.27 tb: 17.79 tb used by data, zero for snapshots and 9.48 tb of free space. i am unaware of how the box was originally set up (i.e. disk order and expansion process) but any ideas why this is please? we use this as a backup nas so if needed, we could do a factory reset with the drives in place if that meant we’d regain the missing tb.
on the topic of luns, • what is the maximum sized lun that can be created on the pro 4?
• the recommendation when setting up block sizes was that they should mirror one another. when creating luns on the pro 4, the default block size is 512, whereas when formatting under windows, the default setting is 4096. bench tests suggest there isn’t a great deal of difference in terms of performance between the two, so when used to copy a mix of small and large file sizes (including system files), is there a setting the pro 4 likes best?
• we also have some large virtual machine files that require backing up. valuing ease of use, future compatibility and disk utilisation over speed/time, what advantages/disadvantages are there to using a sector size of 64k for this particular lun?
• sync writes are allowed by default. the manual on p69 and p100 references this but not in any detail. can somebody explain its purpose and the best way to use this setting please?
we have a backup pro 4 using os 6.10.8 which is populated with 2 x 10 tb (9.1) and 2 x 16 tb (14.6) disks running x-raid (raid 5). no snapshot space is allocated to or used by any of the thick luns set up on the system, so as i understand it, the total volume size should equate to approximately 32.8 tb of usable space. however, our total volume reports 27.27 tb: 17.79 tb used by data, zero for snapshots and 9.48 tb of free space. i am unaware of how the box was originally set up (i.e. disk order and expansion process) but any ideas why this is please?
27.27 TiB is 30 TB, so this sounds like either XRAID expansion failed (or that the unit is actually set up for RAID-5/FlexRAID). (4x10TB RAID-5 would give 30 TB). You could look into the history more by downloading the full log zip file. Status.log might go back far enough.
Looking at lsblk.log and mdstat.log would also give you clues on why the volume is the size it is (and the partition and RAID group structure would give some information on the expansion history).
You might be able to manually expand the volume with ssh (and a factory default should also give you the full size)
