> On Nov 4, 2020, at 9:21 PM, John Pierce <jhn.pierce at gmail.com> wrote: > > is it RAID 0 (striped) or raid1 (mirrored) ?? > > if you wrote on half of a raid0 stripe set, you basically trashed it. > blocks are striped across both drives, so like 16k on the first disk, then > 16k on the 2nd then 16k back on the first, repeat (replace 16k with > whatever your raid stripe size is). > > if its a raid 1 mirror, then either disk by itself has the complete file > system on it, so you should be able to remirror the changed disk onto the > other drive. you MUST do that re-mirror because your two disks are no > longer identical, and reads will alternate between them, so some reads will > get new data and others will get old data, which will be highly chaotic. > John, I figure, BIOS RAID is essentially software RAID (handled by Linux kernel’s md module, or whatever module's name is). I have a question then. If it were RAID-1, and one of the drives was mounted, would the kernel’s md (?) module recognize that the other drive is out of sync, - there should be timestamp when each of RAID members was last in sync/used. Right? Or I am mistaken? If I understand correctly, OP has, or rather had (uh-huh), RAID-0. Valeri PS. I thought I was wrong, but I was mistaken ;-) > > > On Wed, Nov 4, 2020 at 6:18 PM H <agents at meddatainc.com> wrote: > >> My computer running CentOS 7 is configured to use BIOS RAID0 and has two >> identical SSDs which are also encrypted. I had a crash the other day and >> due to a bug in the operating system update, I am unable to boot the system >> in RAID mode since dracut does not recognize the disks in grub. After >> modifying the grub command line I am able to boot the system from one of >> the harddisks after entering the LUKS password, seemingly without any >> problems but am obviously not running in RAID0 mode. When I booted in >> single-disk mode I am sure there were some new files created on the single >> SSD the system sees but I fairly quickly shut it down until this can be >> fixed. >> >> >> >> My question is: once the operating system fix has been released and I can >> once again boot in BIOS RAID0 mode and decrypting both SSDs (same password >> entered only once of course), how will the BIOS RAID0 react? How will it >> handle new files on one disk, altered timestamps etc.? >> >> >> Thanks. >> >> _______________________________________________ >> CentOS mailing list >> CentOS at centos.org >> https://lists.centos.org/mailman/listinfo/centos >> > > > -- > -john r pierce > recycling used bits in santa cruz > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos